A server is a computer that responds to requests from clients like web browsers. Common requests include serving web pages, uploading/downloading files, and sending email. Apache is a popular web server software that runs on 66% of websites. It is feature-rich, efficient, robust, secure, and open source. A port is a software connection between a server and client used to identify the service, like port 80 for HTTP. Servlets are Java programs that extend functionality of web servers. They have advantages over CGI scripts like improved performance from residing in memory.
Servlet API life cycle methods
init(): called when servlet is instantiated; must return before any other methods will be called
service(): method called directly by server when an HTTP request is received; default service() method calls doGet() (or related methods covered later)
destroy(): called when server shuts down
This document provides an overview of server-side web programming and different technologies used to create dynamic web pages, including Common Gateway Interface (CGI), servlets, and JavaServer Pages (JSP). CGI allows building dynamic web sites by running programs on the server that can generate HTML responses. Servlets provide a Java-based alternative to CGI with improved performance, portability, and security. Servlets use a request-response model and are executed by a servlet container. JSP is a technology that simplifies web page programming by mixing static elements like HTML with scripting code.
Servlets are Java classes that extend the functionality of a web server by dynamically generating web pages. Servlets use the Java programming language and are managed by a servlet container that handles loading, unloading, and directing requests. Servlets provide advantages over older technologies like CGI scripts such as better performance, portability, security, and access to full Java features. The basic servlet lifecycle involves initialization, handling requests, and destruction. Servlets can be generic or HTTP-specific, with HTTP servlets providing specialized methods for different HTTP request types. Sessions allow servlets to maintain state across multiple requests.
Servlet is java class which extends the functionality of web server by dynamically generating web pages.
Servlet technology is used to create Dynamic web application. Servlet technology is robust and scalable. init() and service() methods are more important in life cycle of a servlet. doGet() and doPost() are methods used under service() method.
The document provides an overview of servlets and related technologies. It discusses that servlets are Java programs that run on a web or application server, process client requests, and produce dynamic web pages. Servlets act as a middle layer between requests from browsers/clients and databases on the server. The document also covers common gateway interface (CGI), GET and POST methods, query strings, advantages of servlets over CGI, the servlet API, servlet lifecycle, session tracking techniques including cookies, and examples of using cookies to track sessions.
This document summarizes how to build a web application using Flask. It introduces HTTP requests and responses, and how Flask works with request and response objects. It then provides an example of building a basic Flask app with a view function to display "Hello World", and how to use Jinja templates to separate code and markup. The document also discusses using HTML forms to submit data via GET and POST requests.
Servlets are Java programs that run on a web or application server and act as a middle layer between a request coming from a web browser or other HTTP client and databases or applications on the HTTP server. Servlets receive HTTP requests and return HTTP responses by accepting request parameters, generating dynamic content, accessing databases, and performing network communications using Java. Servlets are commonly used to add dynamic content to web pages and to access backend databases. The lifecycle of a servlet involves initialization, servicing client requests, and destruction. Common servlet APIs include classes for handling HTTP requests and responses, reading request parameters, using cookies and sessions.
Python Flask Tutorial For Beginners | Flask Web Development Tutorial | Python...Edureka!
This document provides an overview of Flask, a Python-based web application framework. It begins with an introduction to Flask, explaining what Flask is and its advantages like being open source with a large community. It then covers topics like installing Flask, creating Flask applications, routing, templates, static files, the request object, cookies, redirects and errors. It concludes by mentioning some popular Flask extensions that add additional functionality for tasks like email, forms, databases and AJAX. The document appears to be from an online training course on Flask and aims to teach the basics of how to use the Flask framework to build web applications.
This document discusses servlets, which are Java programs that extend the capabilities of web servers to enable dynamic web content. Servlets run on the server-side and generate HTML responses to HTTP requests from clients. The document covers the basics of servlets, how they interface with web servers, their lifecycle including initialization and destruction, advantages over previous technologies like CGI, and implementation details.
The document provides an overview of advanced patterns in Flask including:
1. State management using application and request contexts to bind resources like databases.
2. Resource management using teardown callbacks to commit transactions and release resources.
3. Customizing response creation by passing response objects down a stack or replacing implicit responses.
4. Server-sent events for real-time updates using Redis pub/sub and streaming responses.
5. Separating worker processes for blocking and non-blocking tasks using tools like Gunicorn and Nginx.
6. Signing data with ItsDangerous to generate tokens and validate user activations without a database.
7. Customizing Flask like adding cache bust
Servlets are Java programs that run on the server-side and dynamically generate web pages using Java code. Servlets provide server-side programming functionality and are an effective replacement for CGI scripts. Servlets follow a standard API and can be deployed across distributed server environments.
This document provides an overview of Java servlets, including what servlets are, their advantages over other technologies like CGI scripts, their lifecycle and program structure, deploying servlets on Tomcat, HTTP request methods, accessing request data, and redirecting URLs. Servlets are Java classes that extend functionality to handle HTTP requests and responses. They have advantages like faster performance than CGI scripts and reuse of the Java platform. The servlet lifecycle involves initialization, processing requests, and destruction. Servlets are deployed on a web container like Tomcat by compiling, configuring in web.xml, and placing in the webapps folder.
This document provides an overview of servlets and related Java web application concepts. It discusses the servlet lifecycle, how servlets handle HTTP requests and responses, and how they fit into the Java EE context. It also covers servlet containers, the model-view-controller pattern, using servlet contexts and configurations, session management, filters, and multithreading issues.
This document provides instructions for building a RESTful API with Flask that allows users to be created, viewed, updated, and deleted. It discusses installing Python, Flask, Flask-SQLAlchemy, and Flask-Marshmallow. It then demonstrates how to create a user model and schema, and build API endpoints to add a new user, retrieve all users, get a single user by ID, update a user, and delete a user. Finally, it provides instructions for running the application and testing the API with Postman.
A Java servlet is a server-side program that processes requests from clients. Servlets offer improved performance over CGI by remaining loaded in memory between requests. The Servlet API defines interfaces and classes for writing servlets, including Servlet, ServletRequest, and ServletResponse. Tomcat is a popular servlet container for developing and testing servlets. A basic "Hello World" servlet uses the Servlet API to write a response containing HTML.
Server side programs can be written using different server-side technologies , such as Common Gateway Interface (CGI) , Active Server Pages (ASP) and Servlets.
CGI scripts are written in C , C++ or perl programming languages .
In case of an application server using CGI script to process client request , the server creates a separate instance of the CGI script to process the request.
As a result, the efficiency of the server is affected when there is large number of concurrent requests.
This document provides an overview of Java servlets technology, including:
1. What Java servlets are and their main purposes and advantages such as portability, power, and integration with server APIs.
2. Key aspects of servlet architecture like the servlet lifecycle, the HttpServletRequest and HttpServletResponse objects, and how different HTTP methods map to servlet methods.
3. Examples of simple servlets that process parameters, maintain a session counter, and examples of deploying servlets in Eclipse IDE.
This document provides an overview of web application development and servlet technology. It discusses the history and evolution of web pages to dynamic web applications. It then defines web applications and the request-response model. Common Gateway Interface (CGI) is introduced as the first technique for dynamic content, along with its limitations which led to the creation of servlets. Key servlet concepts like the servlet interface, generic servlet, HTTP servlet, and servlet lifecycle methods are covered. The document also examines the HttpServletRequest and HttpServletResponse interfaces and their various methods. Finally, it discusses session tracking approaches including cookies and the session API.
GenericServlet defines a generic, protocol-independent servlet that uses the service() method to handle requests. HttpServlet extends GenericServlet to define an HTTP protocol specific servlet that uses doGet and doPost methods to handle requests. Servlets follow a lifecycle of initialization, service, and destruction when loaded and unloaded from the servlet container.
This document provides information on Java servlets including: what servlets are and their advantages; the servlet architecture and lifecycle including initialization, processing requests via doGet and doPost methods, and destruction; how to deploy servlets in an application server; and how servlets handle form data submission. Servlets act as a middle layer between web requests and applications/databases, and allow dynamically generating web pages.
The document discusses servlets and how they work. Servlets are server-side Java programs that generate responses, usually in the form of HTML pages, to requests from web clients. Servlets run within a servlet container, which manages loading and executing servlets in response to requests. Servlets can access request parameters and session information, generate dynamic content, connect to databases, and more. Common methods include doGet() and doPost() to handle different HTTP request types.
This article tries to demystify HTTP, "servlet", "web server", "application server", "servlet container" and gives the fundamentals of the Java Servlet API (that comes with the J2EE SDK).
Java servlets are server-side Java programs that run within a web server and act as a middle layer between requests from web browsers and databases or applications on the server. Servlets have advantages over other server-side technologies like CGI in that they are persistent, portable, server-independent, and faster since they are compiled to bytecode. To run a servlet, you create a directory structure under Tomcat for the application, write and compile the servlet source code, create a deployment descriptor, run Tomcat, and call the servlet from a browser.
Matt Gauger - Lamp vs. the world - MKE PHP Users Group - December 14, 2010 Matt Gauger
This document summarizes a talk comparing PHP and Rails web development frameworks. It discusses the evolution of web servers from Apache to more scalable options like Nginx. Nginx acts as a reverse proxy, passing requests to application servers like FastCGI that execute code and return responses. This represents a shift from simply serving static files to building full-featured web applications using the MVC pattern. Node.js is presented as the next step, allowing JavaScript to be used for server-side development in an event-driven, non-blocking way.
This document provides an overview of Java servlets including:
- Servlets allow Java code to generate dynamic web page content in response to HTTP requests. They are hosted by a servlet container inside a web server.
- The servlet lifecycle involves initialization, processing requests, and destruction. Common methods are init(), service(), destroy().
- The javax.servlet and javax.servlet.http APIs provide interfaces and classes for building servlets and handling HTTP requests/responses.
- Servlets can collaborate by forwarding or redirecting requests between servlets using methods like RequestDispatcher and HttpServletResponse.
- Session management techniques like cookies, hidden fields, and HTTP sessions allow servlets to maintain state across
Web Component Development Using Servlet & JSP Technologies (EE6) - Chapter 4...WebStackAcademy
Setting up a servlet environment
Servlets are Java programs that run on a Web server and build Web pages. Here are a few definitions:
Servlet Development Kits
Java Servlet Development Kit (JSDK) provides Servlet API classes (servlet.jar). Place servlet.jar into CLASSPATH, so that java classes can access it.
Servlet Engines
A servlet is a Java class that needs to be executed in a Java VM by servlet engine. The servlet engine loads the servlet class the first time the servlet is requested. The servlet then stays loaded to handle multiple requests until it is explicitly unloaded or the servlet engine is shut down.
Following are few WebServers that supports servlets:
Apache Tomcat
BEA WebLogic
IBM Websphere
Sun's Java Web Server (JWS)
Apache Tomcat.
Java Servlet Development Kit (JSDK)
The document provides information on various web server software, web application servers, HTTP requests and responses, and the differences between web servers and application servers. It also discusses servlets, web applications, and the servlet API. Specifically, it lists popular web server software like Apache HTTP Server, Microsoft IIS, and Apache Tomcat. It explains how web application servers extend web servers to support dynamic content through templates, programs, and databases. It also defines the key components of HTTP requests and responses.
Servlet
Common Gateway Interface (CGI), Lifecycle of a Servlet, deploying a servlet, The Servlet API, Reading Servlet parameters, Reading Initialization parameters, Handling Http Request & Responses, Using Cookies and Sessions, connecting to a database using JDBC.
This talk was given at the Dutch PHP Conference 2011 and details the use of Comet (aka reverse ajax or ajax push) technologies and the importance of websockets and server-sent events. More information is available at http://joind.in/3237.
The document discusses servlets, including their life cycle, handling HTTP requests and responses, and session tracking using cookies. It provides details on:
- The init(), service(), and destroy() methods that are central to a servlet's life cycle.
- How servlets can read data from HTTP requests using the HttpServletRequest interface and write data to HTTP responses using the HttpServletResponse interface.
- How servlets can maintain session state across requests using the HttpSession interface and cookies.
- Examples of simple servlets that retrieve and display request parameters, and handle GET and POST requests.
Server-side programming with Java servlets allows dynamic web content generation. Servlets extend the capabilities of web servers by responding to incoming requests. A servlet is a Java class that implements the servlet interface. It handles HTTP requests and responses by overriding methods like doGet() and doPost(). Servlets provide better performance than CGI by using threads instead of processes to handle requests. They also offer portability, robustness, and security due to being implemented in Java. Sessions allow servlets to maintain state across multiple requests from the same user by utilizing session IDs stored in cookies.
Server-side programming with Java servlets allows dynamic web content generation. A servlet is a Java class that extends HTTP servlet functionality. It handles HTTP requests and responses by overriding methods like doGet() and doPost(). Servlets offer benefits over older CGI technologies like improved performance through multithreading and portability through the Java programming language. Servlets communicate with clients via HTTP request and response objects, and can establish sessions to identify users across multiple requests.
The document discusses Java servlets and server-side programming. It defines servlets as Java programs that extend the capabilities of web servers. Servlets can respond dynamically to web requests and are used to create dynamic web content. The document outlines the servlet lifecycle and how servlets handle HTTP requests and responses through request and response objects. It also discusses advantages of servlets like performance and portability compared to older CGI technologies.
This document provides an introduction to servlets, including concepts of CGI, advantages of servlets over CGI, servlet life cycle, servlet deployment, and servlet API. Some key points:
- CGI enables a web server to call an external program and pass HTTP request information, but has performance and scalability disadvantages due to starting a new process for each request.
- Servlets address CGI limitations by running within a JVM on the server, allowing requests to be handled on threads rather than processes for better performance.
- The servlet life cycle includes initialization via init(), processing requests via service()/doGet()/doPost(), and cleanup via destroy().
- Servlets are deployed by placing class
The document discusses the control-view architecture pattern for server-side web programming. Servlets act as controllers that categorize requests and decide which JSP view to forward the request to. Information can be passed from the servlet to the JSP using request attributes. Servlets are classes that contain methods executed by the server in response to requests, rather than generating web pages directly.
The document provides an overview of servlets, including:
- What servlets are and how they work
- The lifecycle of a servlet from initialization to handling requests to destruction
- Options for server-side development like CGI, FastCGI, PHP
- Advantages of using servlets like performance, portability, and security
Java Web Programming [2/9] : Servlet BasicIMC Institute
This document provides an overview of servlets, including:
- Servlets extend the functionality of HTTP servers and allow for dynamic content generation.
- Servlets handle requests and responses more efficiently than CGI due to being server-independent and allowing for session management.
- The servlet lifecycle includes initialization, request handling, and destruction. Common methods are init(), service(), doGet(), doPost(), and destroy().
- Servlets extract information from HTTP requests and use this to generate and return HTTP responses by setting headers and writing response content.
Http Server Programming in JAVA - Handling http requests and responsesbharathiv53
This ppt contains HTML forms and CGI; HTTP; Servlet Programming; The Life Cycle of a
Servlet; Using Tomcat for Servlet Development; A simple Servlet;
deployment of simple servlets, web server (Java web server / Tomcat/ Web
logic) The Servlet API; The Javax.servlet Package; Reading Servlet
Parameter; The Javax.servlet.http package; Handling HTTP Requests and
Responses, HTTP GET and POST methods, Using Cookies; Session
Tracking
This document provides an overview of servlets and Java EE. It discusses what servlets are, how they work, their lifecycle, and how to handle GET and POST requests. Servlets are Java programs that extend HttpServlet to create dynamic web applications. They receive and respond to requests via doGet() and doPost() methods. The document also covers servlet API, environments for developing servlets, MIME types, and handling GET/POST requests by overriding doGet() and doPost(). The next session will demonstrate a complete web application flow with servlet coding.
Mulesoft is an open source integration platform that allows users to connect different applications and platforms through a Java-based enterprise service bus. It can exchange data in real-time or batch modes between systems like JMS, Salesforce, HTTP, web services, and JDBC. Mulesoft is platform independent, integrates a wide variety of applications, and allows business logic to remain separate from messaging logic. To get certified in Mulesoft, users can study free online materials on the Mulesoft training site and take an open book, unproctored exam within 90 minutes after 8 weeks of study. Users are encouraged to thoroughly review materials, take notes, complete exercises, and engage with online communities to best prepare
MuleSoft is an integration platform that allows developers to connect applications together using Mule, its lightweight Java-based enterprise service bus (ESB). Anypoint Studio is MuleSoft's graphical development tool for building, testing, and deploying integrations. JMS is an API that enables loosely-coupled, reliable messaging between distributed application components using queues or topics. The document provides steps for using File, File-to-String, and JMS connectors in MuleSoft to place a file in a JMS queue.
This document provides an overview of using Mule to integrate with web services. It discusses building a bookstore web service using JAX-WS, generating a client, and configuring Mule with a CXF connector. It also covers transforming CSV book data to objects and sending to the web service, and transforming order objects to emails and sending via SMTP. The key steps are building the web service, generating a client, developing message transformers, and configuring Mule endpoints and routing.
The document provides an overview of the Perl programming language. It discusses that Perl stands for Practical Extraction and Reporting Language and is similar to shell script but more powerful and easier. It then covers basic Perl concepts like file extensions, self-executing scripts, advantages over other languages, and using print statements. The document also summarizes storing values using scalar and list variables, control structures, regular expressions, functions, and more advanced Perl topics.
Hibernate is an object-relational mapping tool that allows developers to interact with a relational database (such as MySQL) using object-oriented programming. It provides functionality for persisting Java objects to tables in a database and querying those objects using HQL or SQL. Hibernate utilizes XML mapping files or annotations to define how Java classes map to database tables. A typical Hibernate application includes entity classes, mapping files, configuration files, and a controller class to manage persistence operations.
The document provides an overview of the Java Persistence API (JPA). It defines JPA as a framework that helps developers control relational data in Java applications. JPA offers developers an easier way to access and manipulate relational data compared to previous solutions. It consists of the JPA API, the Java Persistence Query Language (JPQL), and object-relational metadata. JPA defines a runtime API to process queries and transactions on objects against a database, and JPQL allows querying objects from the database in a SQL-like syntax. The document also compares JPA to EJB solutions, noting advantages like reduced complexity and the ability to use outside an application server.
Spring is an open source Java application framework that uses dependency injection and inversion of control to reduce coupling between application layers. It includes modules for core functions, aspects, data access, web MVC, and other services. Spring promotes loose coupling, testability, and separation of concerns through its lightweight container that manages lifecycles and dependencies of application components.
JSON is a lightweight data format that can represent complex data structures like objects and arrays. It is useful for AJAX applications because JSON data can be easily evaluated and accessed in JavaScript. JSON has advantages over XML in AJAX as data can be accessed at any depth without additional processing, and JSON syntax is simpler. However, using JSON in AJAX also raises security concerns due to the ability of malicious scripts to access sensitive transmitted data.
The Spring Framework provides an inversion of control container and aspects for aspect-oriented programming. It includes services for data access, exceptions, ORM tools, web services, messaging and scheduling. It also offers a full MVC framework with clear separation of controller, validator, form object and view resolver roles. The Spring Framework has benefits like code extensibility, readability and replaceable modules, as well as transaction handling and security through AOP.
REST is a style of software architecture for distributed hypermedia systems such as the World Wide Web. It uses a stateless, client-server, cacheable communications protocol and standard interface to access and manipulate representations of web resources. The key aspects of REST include using a uniform interface, separating concerns through resources and representations, and hypermedia as the engine of application state. REST contrasts with SOAP which is message-oriented and focuses on integrated applications rather than interacting with resources. While REST and SOA share some principles like loose coupling and statelessness, REST emphasizes resources and representations over messages and operations.
Exceptions in Java allow programs to handle errors and unexpected conditions in a uniform way. Exceptions break normal program flow and can be caught and handled in catch blocks. Common exceptions include runtime exceptions for errors like null pointer exceptions and checked exceptions for errors like IOExceptions. Exceptions are organized in a hierarchy with Throwable at the top. The Java compiler enforces exception handling to improve correctness.
This document provides an overview of JUnit, a unit testing framework for Java. It discusses JUnit's history and development by Kent Beck and others. The key aspects covered include: writing test cases by extending TestCase and adding test methods; using assertion methods like assertTrue and assertEquals to check conditions; organizing tests into test suites; and running JUnit tests within the Eclipse IDE. Other unit testing tools for other languages are also briefly mentioned.
XML parsers are software libraries that allow client applications to work with XML documents. There are two main types: DOM parsers build an in-memory tree representation, while SAX parsers use event-based callbacks. Xerces-J is a popular Java XML parser that implements both DOM and SAX interfaces. An example extracts circle data from an XML file using both a DOM parser to iterate through nodes and a SAX parser overriding callback methods.
XPath is a syntax for selecting parts of an XML document, similar to how file paths work in an operating system. It allows selecting elements, attributes, and text from an XML document. XPath uses paths containing axis, nodes, and predicates to navigate within an XML document. Common axes include child, parent, ancestor, descendant, following, and preceding. Functions, arithmetic expressions, and other features allow complex querying of XML documents.
XSLT is used to transform XML documents into other formats like HTML. It uses an XML document and an XSL stylesheet to perform the transformation. The XSL stylesheet contains templates that are applied to the XML data to output a new formatted document. Common XSL elements include xsl:value-of to output node values, xsl:for-each for loops, and xsl:apply-templates to apply templates to child nodes. XSLT provides powerful tools for transforming XML but requires careful debugging due to its complexity.
XHTML was created to replace HTML and is defined using XML rather than SGML. It is nearly identical to HTML but aims to be cleaner and more extensible by requiring elements to be properly nested, closed, and case-sensitive. Documents must also have a DOCTYPE declaration and refer to a DTD that defines syntax requirements. There are three main DTDs that can be used with XHTML - Strict, Transitional, and Frameset - depending on whether style information or frames are needed.
Cascading Style Sheets (CSS) is used to separate a document's semantics from its presentation. CSS allows content to be displayed differently on different devices. CSS rules consist of selectors and declarations blocks. The CSS box model represents elements as boxes that can be sized and positioned with properties like width, height, padding, borders, and margins. CSS handles conflicts between rules through specificity, source order, and inheritance to determine which styles get applied.
HTML5 is the newest version of HTML that simplifies elements and syntax compared to previous versions. It was first published in 2012 but has been in development since 2004. HTML5 incorporates features from earlier HTML versions and adds new tools for developers, though full browser support will take many years. The document provides examples of simplified DOCTYPE, HTML, HEAD, and BODY elements in HTML5 compared to previous versions like XHTML.
The document discusses AJAX (Asynchronous JavaScript and XML), which allows web pages to be updated asynchronously by exchanging data with a web server behind the scenes, without reloading the entire page. It provides an overview of the basic objects and steps needed to make AJAX work, including the XMLHttpRequest object, how servers respond, and using the response. It then contrasts the traditional synchronous web page model with AJAX's asynchronous approach. The document also covers the basics of writing AJAX applications, including creating XMLHttpRequest objects, sending requests, handling responses, and using properties and methods. Finally, it provides a skeleton for a general AJAX application and an example to get the time from the server without refreshing the whole page.
Scaling Connections in PostgreSQL Postgres Bangalore(PGBLR) Meetup-2 - MydbopsMydbops
This presentation, delivered at the Postgres Bangalore (PGBLR) Meetup-2 on June 29th, 2024, dives deep into connection pooling for PostgreSQL databases. Aakash M, a PostgreSQL Tech Lead at Mydbops, explores the challenges of managing numerous connections and explains how connection pooling optimizes performance and resource utilization.
Key Takeaways:
* Understand why connection pooling is essential for high-traffic applications
* Explore various connection poolers available for PostgreSQL, including pgbouncer
* Learn the configuration options and functionalities of pgbouncer
* Discover best practices for monitoring and troubleshooting connection pooling setups
* Gain insights into real-world use cases and considerations for production environments
This presentation is ideal for:
* Database administrators (DBAs)
* Developers working with PostgreSQL
* DevOps engineers
* Anyone interested in optimizing PostgreSQL performance
Contact info@mydbops.com for PostgreSQL Managed, Consulting and Remote DBA Services
Are you interested in dipping your toes in the cloud native observability waters, but as an engineer you are not sure where to get started with tracing problems through your microservices and application landscapes on Kubernetes? Then this is the session for you, where we take you on your first steps in an active open-source project that offers a buffet of languages, challenges, and opportunities for getting started with telemetry data.
The project is called openTelemetry, but before diving into the specifics, we’ll start with de-mystifying key concepts and terms such as observability, telemetry, instrumentation, cardinality, percentile to lay a foundation. After understanding the nuts and bolts of observability and distributed traces, we’ll explore the openTelemetry community; its Special Interest Groups (SIGs), repositories, and how to become not only an end-user, but possibly a contributor.We will wrap up with an overview of the components in this project, such as the Collector, the OpenTelemetry protocol (OTLP), its APIs, and its SDKs.
Attendees will leave with an understanding of key observability concepts, become grounded in distributed tracing terminology, be aware of the components of openTelemetry, and know how to take their first steps to an open-source contribution!
Key Takeaways: Open source, vendor neutral instrumentation is an exciting new reality as the industry standardizes on openTelemetry for observability. OpenTelemetry is on a mission to enable effective observability by making high-quality, portable telemetry ubiquitous. The world of observability and monitoring today has a steep learning curve and in order to achieve ubiquity, the project would benefit from growing our contributor community.
How Social Media Hackers Help You to See Your Wife's Message.pdfHackersList
In the modern digital era, social media platforms have become integral to our daily lives. These platforms, including Facebook, Instagram, WhatsApp, and Snapchat, offer countless ways to connect, share, and communicate.
Best Programming Language for Civil EngineersAwais Yaseen
The integration of programming into civil engineering is transforming the industry. We can design complex infrastructure projects and analyse large datasets. Imagine revolutionizing the way we build our cities and infrastructure, all by the power of coding. Programming skills are no longer just a bonus—they’re a game changer in this era.
Technology is revolutionizing civil engineering by integrating advanced tools and techniques. Programming allows for the automation of repetitive tasks, enhancing the accuracy of designs, simulations, and analyses. With the advent of artificial intelligence and machine learning, engineers can now predict structural behaviors under various conditions, optimize material usage, and improve project planning.
INDIAN AIR FORCE FIGHTER PLANES LIST.pdfjackson110191
These fighter aircraft have uses outside of traditional combat situations. They are essential in defending India's territorial integrity, averting dangers, and delivering aid to those in need during natural calamities. Additionally, the IAF improves its interoperability and fortifies international military alliances by working together and conducting joint exercises with other air forces.
Sustainability requires ingenuity and stewardship. Did you know Pigging Solutions pigging systems help you achieve your sustainable manufacturing goals AND provide rapid return on investment.
How? Our systems recover over 99% of product in transfer piping. Recovering trapped product from transfer lines that would otherwise become flush-waste, means you can increase batch yields and eliminate flush waste. From raw materials to finished product, if you can pump it, we can pig it.
Transcript: Details of description part II: Describing images in practice - T...BookNet Canada
This presentation explores the practical application of image description techniques. Familiar guidelines will be demonstrated in practice, and descriptions will be developed “live”! If you have learned a lot about the theory of image description techniques but want to feel more confident putting them into practice, this is the presentation for you. There will be useful, actionable information for everyone, whether you are working with authors, colleagues, alone, or leveraging AI as a collaborator.
Link to presentation recording and slides: https://bnctechforum.ca/sessions/details-of-description-part-ii-describing-images-in-practice/
Presented by BookNet Canada on June 25, 2024, with support from the Department of Canadian Heritage.
UiPath Community Day Kraków: Devs4Devs ConferenceUiPathCommunity
We are honored to launch and host this event for our UiPath Polish Community, with the help of our partners - Proservartner!
We certainly hope we have managed to spike your interest in the subjects to be presented and the incredible networking opportunities at hand, too!
Check out our proposed agenda below 👇👇
08:30 ☕ Welcome coffee (30')
09:00 Opening note/ Intro to UiPath Community (10')
Cristina Vidu, Global Manager, Marketing Community @UiPath
Dawid Kot, Digital Transformation Lead @Proservartner
09:10 Cloud migration - Proservartner & DOVISTA case study (30')
Marcin Drozdowski, Automation CoE Manager @DOVISTA
Pawel Kamiński, RPA developer @DOVISTA
Mikolaj Zielinski, UiPath MVP, Senior Solutions Engineer @Proservartner
09:40 From bottlenecks to breakthroughs: Citizen Development in action (25')
Pawel Poplawski, Director, Improvement and Automation @McCormick & Company
Michał Cieślak, Senior Manager, Automation Programs @McCormick & Company
10:05 Next-level bots: API integration in UiPath Studio (30')
Mikolaj Zielinski, UiPath MVP, Senior Solutions Engineer @Proservartner
10:35 ☕ Coffee Break (15')
10:50 Document Understanding with my RPA Companion (45')
Ewa Gruszka, Enterprise Sales Specialist, AI & ML @UiPath
11:35 Power up your Robots: GenAI and GPT in REFramework (45')
Krzysztof Karaszewski, Global RPA Product Manager
12:20 🍕 Lunch Break (1hr)
13:20 From Concept to Quality: UiPath Test Suite for AI-powered Knowledge Bots (30')
Kamil Miśko, UiPath MVP, Senior RPA Developer @Zurich Insurance
13:50 Communications Mining - focus on AI capabilities (30')
Thomasz Wierzbicki, Business Analyst @Office Samurai
14:20 Polish MVP panel: Insights on MVP award achievements and career profiling
Implementations of Fused Deposition Modeling in real worldEmerging Tech
The presentation showcases the diverse real-world applications of Fused Deposition Modeling (FDM) across multiple industries:
1. **Manufacturing**: FDM is utilized in manufacturing for rapid prototyping, creating custom tools and fixtures, and producing functional end-use parts. Companies leverage its cost-effectiveness and flexibility to streamline production processes.
2. **Medical**: In the medical field, FDM is used to create patient-specific anatomical models, surgical guides, and prosthetics. Its ability to produce precise and biocompatible parts supports advancements in personalized healthcare solutions.
3. **Education**: FDM plays a crucial role in education by enabling students to learn about design and engineering through hands-on 3D printing projects. It promotes innovation and practical skill development in STEM disciplines.
4. **Science**: Researchers use FDM to prototype equipment for scientific experiments, build custom laboratory tools, and create models for visualization and testing purposes. It facilitates rapid iteration and customization in scientific endeavors.
5. **Automotive**: Automotive manufacturers employ FDM for prototyping vehicle components, tooling for assembly lines, and customized parts. It speeds up the design validation process and enhances efficiency in automotive engineering.
6. **Consumer Electronics**: FDM is utilized in consumer electronics for designing and prototyping product enclosures, casings, and internal components. It enables rapid iteration and customization to meet evolving consumer demands.
7. **Robotics**: Robotics engineers leverage FDM to prototype robot parts, create lightweight and durable components, and customize robot designs for specific applications. It supports innovation and optimization in robotic systems.
8. **Aerospace**: In aerospace, FDM is used to manufacture lightweight parts, complex geometries, and prototypes of aircraft components. It contributes to cost reduction, faster production cycles, and weight savings in aerospace engineering.
9. **Architecture**: Architects utilize FDM for creating detailed architectural models, prototypes of building components, and intricate designs. It aids in visualizing concepts, testing structural integrity, and communicating design ideas effectively.
Each industry example demonstrates how FDM enhances innovation, accelerates product development, and addresses specific challenges through advanced manufacturing capabilities.
7 Most Powerful Solar Storms in the History of Earth.pdfEnterprise Wired
Solar Storms (Geo Magnetic Storms) are the motion of accelerated charged particles in the solar environment with high velocities due to the coronal mass ejection (CME).
Fluttercon 2024: Showing that you care about security - OpenSSF Scorecards fo...Chris Swan
Have you noticed the OpenSSF Scorecard badges on the official Dart and Flutter repos? It's Google's way of showing that they care about security. Practices such as pinning dependencies, branch protection, required reviews, continuous integration tests etc. are measured to provide a score and accompanying badge.
You can do the same for your projects, and this presentation will show you how, with an emphasis on the unique challenges that come up when working with Dart and Flutter.
The session will provide a walkthrough of the steps involved in securing a first repository, and then what it takes to repeat that process across an organization with multiple repos. It will also look at the ongoing maintenance involved once scorecards have been implemented, and how aspects of that maintenance can be better automated to minimize toil.
Advanced Techniques for Cyber Security Analysis and Anomaly DetectionBert Blevins
Cybersecurity is a major concern in today's connected digital world. Threats to organizations are constantly evolving and have the potential to compromise sensitive information, disrupt operations, and lead to significant financial losses. Traditional cybersecurity techniques often fall short against modern attackers. Therefore, advanced techniques for cyber security analysis and anomaly detection are essential for protecting digital assets. This blog explores these cutting-edge methods, providing a comprehensive overview of their application and importance.
An invited talk given by Mark Billinghurst on Research Directions for Cross Reality Interfaces. This was given on July 2nd 2024 as part of the 2024 Summer School on Cross Reality in Hagenberg, Austria (July 1st - 7th)
Paradigm Shifts in User Modeling: A Journey from Historical Foundations to Em...Erasmo Purificato
Slide of the tutorial entitled "Paradigm Shifts in User Modeling: A Journey from Historical Foundations to Emerging Trends" held at UMAP'24: 32nd ACM Conference on User Modeling, Adaptation and Personalization (July 1, 2024 | Cagliari, Italy)
Quality Patents: Patents That Stand the Test of TimeAurora Consulting
Is your patent a vanity piece of paper for your office wall? Or is it a reliable, defendable, assertable, property right? The difference is often quality.
Is your patent simply a transactional cost and a large pile of legal bills for your startup? Or is it a leverageable asset worthy of attracting precious investment dollars, worth its cost in multiples of valuation? The difference is often quality.
Is your patent application only good enough to get through the examination process? Or has it been crafted to stand the tests of time and varied audiences if you later need to assert that document against an infringer, find yourself litigating with it in an Article 3 Court at the hands of a judge and jury, God forbid, end up having to defend its validity at the PTAB, or even needing to use it to block pirated imports at the International Trade Commission? The difference is often quality.
Quality will be our focus for a good chunk of the remainder of this season. What goes into a quality patent, and where possible, how do you get it without breaking the bank?
** Episode Overview **
In this first episode of our quality series, Kristen Hansen and the panel discuss:
⦿ What do we mean when we say patent quality?
⦿ Why is patent quality important?
⦿ How to balance quality and budget
⦿ The importance of searching, continuations, and draftsperson domain expertise
⦿ Very practical tips, tricks, examples, and Kristen’s Musts for drafting quality applications
https://www.aurorapatents.com/patently-strategic-podcast.html
Details of description part II: Describing images in practice - Tech Forum 2024BookNet Canada
This presentation explores the practical application of image description techniques. Familiar guidelines will be demonstrated in practice, and descriptions will be developed “live”! If you have learned a lot about the theory of image description techniques but want to feel more confident putting them into practice, this is the presentation for you. There will be useful, actionable information for everyone, whether you are working with authors, colleagues, alone, or leveraging AI as a collaborator.
Link to presentation recording and transcript: https://bnctechforum.ca/sessions/details-of-description-part-ii-describing-images-in-practice/
Presented by BookNet Canada on June 25, 2024, with support from the Department of Canadian Heritage.
2. 2
Servers
A server is a computer that responds to requests from a client
Typical requests: provide a web page, upload or download a file, send
email
A server is also the software that responds to these requests; a
client could be the browser or other software making these
requests
Typically, your little computer is the client, and someone else’s
big computer is the server
However, any computer can be a server
It is not unusual to have server software and client software running on the
same computer
3. 3
Apache
Apache is a very popular server
66% of the web sites on the Internet use Apache
Apache is:
Full-featured and extensible
Efficient
Robust
Secure (at least, more secure than other servers)
Up to date with current standards
Open source
Free
Why use anything else?
4. 4
Ports
A port is a connection between a server and a client
Ports are identified by positive integers
A port is a software notion, not a hardware notion, so there may be very
many of them
A service is associated with a specific port
Typical port numbers:
21—FTP, File Transfer Protocol
22—SSH, Secure Shell
25—SMTP, Simple Mail Transfer Protocol
53—DNS, Domain Name Service
80—HTTP, Hypertext Transfer Protocol
8080—HTTP (used for testing HTTP)
7648, 7649—CU-SeeMe
27960—Quake III
These are the ports
of most interest to us
5. 5
Ports II
My UPenn Web page is:
http://www.cis.upenn.edu/~matuszek
But it is also:
http://www.cis.upenn.edu:80/~matuszek
The http: at the beginning signifies a particular protocol
(communication language), the Hypertext Transfer Protocol
The :80 specifies a port
By default, the Web server listens to port 80
The Web server could listen to any port it chose
This could lead to problems if the port was in use by some other server
For testing servlets, we typically have the server listen to port 8080
In the second URL above, I explicitly sent my request to port 80
If I had sent it to some other port, say, 99, my request would either go
unheard, or would (probably) not be understood
6. 6
CGI Scripts
CGI stands for “Common Gateway Interface”
Client sends a request to server
Server starts a CGI script
Script computes a result for server
and quits
Another client sends a request
client server
client
script
Server starts the CGI script again
Etc.
script
Server returns response to client
7. 7
Servlets
A servlet is like an applet, but on the server side
Client sends a request to server
Server starts a servlet
Servlet computes a result for
server and does not quit
Another client sends a request
client server
client
servlet
Server calls the servlet again
Etc.
Server returns response to client
8. 8
Servlets vs. CGI scripts
Advantages:
Running a servlet doesn’t require creating a separate process
each time
A servlet stays in memory, so it doesn’t have to be reloaded
each time
There is only one instance handling multiple requests, not a
separate instance for every request
Untrusted servlets can be run in a “sandbox”
Disadvantage:
Less choice of languages (CGI scripts can be in any language)
9. 9
Tomcat
Tomcat is the Servlet Engine than handles servlet requests
for Apache
Tomcat is a “helper application” for Apache
It’s best to think of Tomcat as a “servlet container”
Apache can handle many types of web services
Apache can be installed without Tomcat
Tomcat can be installed without Apache
It’s easier to install Tomcat standalone than as part of
Apache
By itself, Tomcat can handle web pages, servlets, and JSP
Apache and Tomcat are open source (and therefore free)
10. 10
Servlets
A servlet is any class that implements the
javax.servlet.Servlet interface
In practice, most servlets extend the
javax.servlet.http.HttpServlet class
Some servlets extend javax.servlet.GenericServlet instead
Servlets, like applets, usually lack a main method, but
must implement or override certain other methods
11. 11
Important servlet methods, I
When a servlet is first started up, its init(ServletConfig config)
method is called
init should perform any necessary initializations
init is called only once, and does not need to be thread-safe
Every servlet request results in a call to
service(ServletRequest request, ServletResponse response)
service calls another method depending on the type of service requested
Usually you would override the called methods of interest, not service
itself
service handles multiple simultaneous requests, so it and the methods it
calls must be thread safe
When the servlet is shut down, destroy() is called
destroy is called only once, but must be thread safe (because other threads
may still be running)
12. 12
HTTP requests
When a request is submitted from a Web page, it is almost always
a GET or a POST request
The HTTP <form> tag has an attribute action, whose value can
be "get" or "post"
The "get" action results in the form information being put after
a ? in the URL
Example:
http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-
8&q=servlets
The & separates the various parameters
Only a limited amount of information can be sent this way
"put" can send large amounts of information
13. 13
Important servlet methods, II
The service method dispatches the following kinds of requests:
DELETE, GET, HEAD, OPTIONS, POST, PUT, and TRACE
A GET request is dispatched to the doGet(HttpServletRequest request,
HttpServletResponse response) method
A POST request is dispatched to the doPost(HttpServletRequest
request, HttpServletResponse response) method
These are the two methods you will usually override
doGet and doPost typically do the same thing, so usually you do the real
work in one, and have the other just call it
public void doGet(HttpServletRequest request,
HttpServletResponse response) {
doPost(request, response);
}
14. 14
A “Hello World” servlet
(from the Tomcat installation documentation)
public class HelloServlet extends HttpServlet {
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String docType =
"<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 " +
"Transitional//EN">n";
out.println(docType +
"<HTML>n" +
"<HEAD><TITLE>Hello</TITLE></HEAD>n" +
"<BODY BGCOLOR="#FDF5E6">n" +
"<H1>Hello World</H1>n" +
"</BODY></HTML>");
}
} Don’t worry, we’ll take this a little at a time!
15. 15
The superclass
public class HelloServlet extends HttpServlet {
Every class must extend GenericServlet or a
subclass of GenericServlet
GenericServlet is “protocol independent,” so you could
write a servlet to process any protocol
In practice, you almost always want to respond to an
HTTP request, so you extend HttpServlet
A subclass of HttpServlet must override at least one
method, usually one doGet, doPost, doPut,
doDelete, init and destroy, or getServletInfo
16. 16
The doGet method
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
This method services a GET request
The method uses request to get the information that was sent to
it
The method does not return a value; instead, it uses response to
get an I/O stream, and outputs its response
Since the method does I/O, it can throw an IOException
Any other type of exception should be encapsulated as a
ServletException
The doPost method works exactly the same way
17. 17
Parameters to doGet
Input is from the HttpServletRequest parameter
Our first example doesn’t get any input, so we’ll discuss this a
bit later
Output is via the HttpServletResponse object, which we
have named response
I/O in Java is very flexible but also quite complex, so this
object acts as an “assistant”
18. 18
Using the HttpServletResponse
The second parameter to doGet (or doPost) is
HttpServletResponse response
Everything sent via the Web has a “MIME type”
The first thing we must do with response is set the MIME type
of our reply: response.setContentType("text/html");
This tells the client to interpret the page as HTML
Because we will be outputting character data, we need a
PrintWriter, handily provided for us by the getWriter method
of response:
PrintWriter out = response.getWriter();
Now we’re ready to create the actual page to be returned
19. 19
Using the PrintWriter
From here on, it’s just a matter of using our PrintWriter,
named out, to produce the Web page
First we create a header string:
String docType =
"<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 " +
"Transitional//EN">n";
This line is technically required by the HTML spec
Browsers mostly don’t care, but HTML validators do care
Then use the println method of out one or more times
out.println(docType +
"<HTML>n" +
"<HEAD> ... </BODY></HTML>");
And we’re done!
20. 20
Input to a servlet
A GET request supplies parameters in the form
URL ? name=value & name=value & name=value
(Illegal spaces added to make it more legible)
Actual spaces in the parameter values are encoded by + signs
Other special characters are encoded in hex; for example, an
ampersand is represented by %26
Parameter names can occur more than once, with
different values
A POST request supplies parameters in the same syntax,
only it is in the “body” section of the request and is
therefore harder for the user to see
21. 21
Getting the parameters
Input parameters are retrieved via messages to the
HttpServletRequest object request
Most of the interesting methods are inherited from the superinterface
ServletRequest
public Enumeration getParameterNames()
Returns an Enumeration of the parameter names
If no parameters, returns an empty Enumeration
public String getParameter(String name)
Returns the value of the parameter name as a String
If the parameter doesn’t exist, returns null
If name has multiple values, only the first is returned
public String[] getParameterValues(name)
Returns an array of values of the parameter name
If the parameter doesn’t exist, returns null
22. 22
Enumeration review
An Enumeration is almost the same as Iterator
It’s an older class, and the names are longer
Example use:
Enumeration e = myVector.elements();
while (e.hasMoreElements()) {
System.out.println(e.nextElement());
}
23. 23
Example of input parameters
public void doGet(HttpServletRequest request,
HttpServletResponse response) {
... stuff omitted ...
out.println("<H1>Hello");
String names[] =
request.getParameterValues("name");
if (names != null)
for (int i = 0; i < names.length; i++)
out.println(" " + names[i]);
out.println("!");
}
24. 24
Java review: Data from Strings
All parameter values are retrieved as Strings
Frequently these Strings represent numbers, and
you want the numeric value
int n = new Integer(param).intValue();
double d = new Double(param).doubleValue();
byte b = new Byte(param).byteValue();
Similarly for short, float, and long
These can all throw a NumberFormatException, which is a
subclass of RuntimeException
boolean p = new Boolean(param).booleanValue();
But:
char c = param.charAt(0);
25. 25
What’s left?
We’ve covered enough so far to write simple servlets,
but not enough to write useful servlets
We still need to be able to:
Use configuration information
Authenticate users
Keep track of users during a session
Retain information across different sessions
Make sure our servlets are thread safe
Communicate between servlets
But remember: The most difficult program in any language is
Hello World!