ZIP, GZIP Streams in java
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This document discusses Java classes for working with archives and compression. It describes GZIPInputStream and GZIPOutputStream for reading and writing gzip-compressed streams. ZipInputStream, ZipOutputStream, and ZipEntry are covered for reading, writing, and working with entries in zip archives. Examples are provided for compressing/decompressing files using gzip and creating/reading zip archives.
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![GZipInputStream
class GZIPInputStream extends InflaterInputStream
public GZIPInputStream(InputStream in, int size) throws IOException
public GZIPInputStream(InputStream in) throws IOException
public int read(byte[] buf, int off, int len) throws IOException
public void close() throws IOException](https://cdn.statically.io/img/www.slideshare.net/data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
ZIP, GZIP Streams in java
- 2. GZipInputStream class GZIPInputStream extends InflaterInputStream public GZIPInputStream(InputStream in, int size) throws IOException public GZIPInputStream(InputStream in) throws IOException public int read(byte[] buf, int off, int len) throws IOException public void close() throws IOException
- 3. GZipOutputStream class GZIPOutputStream extends DeflaterOutputStream public GZIPOutputStream(OutputStream out, int size) public GZIPOutputStream(OutputStream out) throws IOException public synchronized void write(byte[] buf, int off, int len) throws IOException public void finish() throws IOException
- 4. Пример использования (упаковка) FileInputStream fi=null; try{ try{ fi=new FileInputStream("in.txt"); go=new GZIPOutputStream(new BufferedOutputStream(new FileOutputStream("out.gz"))); int l=fi.available(); byte[] b=new byte[l]; fi.read(b); go.write(b); } finally{ if(go!=null) go.close(); if(fi!=null) fi.close(); } }catch(Exception e) { System.out.println(e); }
- 5. Пример использования (распаковка) BufferedOutputStream bo = null; try { try { gi = new GZIPInputStream(new BufferedInputStream(new FileInputStream("out.gz"))); int i=0; bo = new BufferedOutputStream(new FileOutputStream("out2.txt")); while((i=gi.read())!=-1) bo.write(i); } finally { if (gi != null) gi.close(); if (bo != null) bo.close(); } } catch (Exception e) { System.out.println(e); }
- 6. ZipInputStream class ZipInputStream extends InflaterInputStream implements ZipConstants public ZipInputStream(InputStream in) public ZipEntry getNextEntry() throws IOException public void closeEntry() throws IOException public int available() throws IOException public int read(byte[] b, int off, int len) throws IOException public long skip(long n) throws IOException public void close() throws IOException
- 7. ZipOutputStream class ZipOutputStream extends DeflaterOutputStream implements ZipConstants public ZipOutputStream(OutputStream out) public void setComment(String comment) public void setMethod(int method) public void setLevel(int level) public void putNextEntry(ZipEntry e) throws IOException public void closeEntry() throws IOException public synchronized void write(byte[] b, int off, int len) public void finish() throws IOException public void close() throws IOException
- 8. ZipEntry class ZipEntry implements ZipConstants, Cloneable public ZipEntry(String name) public ZipEntry(ZipEntry e) public String getName() public void setTime(long time) public long getTime() public void setSize(long size) public long getSize() public long getCompressedSize() public void setCompressedSize(long csize) public void setMethod(int method) public int getMethod() public void setExtra(byte[] extra) public byte[] getExtra() public void setComment(String comment) public String getComment()
- 9. Пример использования public void createZip() { try { try { zo = new ZipOutputStream(new BufferedOutputStream(new FileOutputStream(s+".zip"))); File f=new File(s); String s1=f.getPath(); addFolderToZip(zo,f.getName(),f); } finally { if (zo != null) { zo.close(); } } } catch (Exception e) { System.out.println(e); } }
- 10. Пример использования (продолжение) public void addFolderToZip(ZipOutputStream zo, String path, File dir) { File[] fs = dir.listFiles(); for (File f : fs) { if (f.isFile()) { addFile(zo, path, f); } else { addFolderToZip(zo, path+""+f.getName(), f); } } }
- 11. Пример использования (продолжение) public void addFile(ZipOutputStream zo, String path, File f) { ZipEntry ze = new ZipEntry(path+""+f.getName()); BufferedInputStream bi = null; try { try { zo.putNextEntry(ze); bi = new BufferedInputStream(new FileInputStream(f.getPath())); byte[] b = new byte[1024]; int i = 0; while ((i = bi.read(b)) != -1) zo.write(b, 0, i); } finally { zo.closeEntry(); if (bi != null) bi.close(); } } catch (IOException e) { System.out.println(e); } }