ZipOutputStream

ZipOutputStream

java.util.zip

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Java 1.1

closeable flushable

This class is a subclass of DeflaterOutputStream that writes data in ZIP file format to an output stream. Before writing any data to the ZipOutputStream , you must begin an entry within the ZIP file with putNextEntry( ) . The ZipEntry object passed to this method should specify at least a name for the entry. Once you have begun an entry with putNextEntry( ) , you can write the contents of that entry with the write( ) methods . When you reach the end of an entry, you can begin a new one by calling putNextEntry( ) again, you can close the current entry with closeEntry( ) , or you can close the stream itself with close( ) .

Before beginning an entry with putNextEntry( ) , you can set the compression method and level with setMethod( ) and setLevel( ) . The constants DEFLATED and STORED are the two legal values for setMethod( ) . If you use STORED , the entry is stored in the ZIP file without any compression. If you use DEFLATED , you can also specify the compression speed/strength tradeoff by passing a number from 1 to 9 to setLevel( ) , where 9 gives the strongest and slowest level of compression. You can also use the constants Deflater.BEST_SPEED , Deflater.BEST_COMPRESSION , and Deflater.DEFAULT_COMPRESSION with the setLevel( ) method.

If you are storing an entry without compression, the ZIP file format requires that you specify, in advance, the entry size and CRC-32 checksum in the ZipEntry object for the entry. An exception is thrown if these values are not specified or specified incorrectly.

Figure 16-147. java.util.zip.ZipOutputStream

 public class  ZipOutputStream  extends DeflaterOutputStream implements ZipConstants {  // Public Constructors  public  ZipOutputStream  (java.io.OutputStream  out  );  // Public Constants  public static final int  DEFLATED  ;  =8  public static final int  STORED  ;  =0   // Public Instance Methods  public void  closeEntry  ( ) throws java.io.IOException;        public void  putNextEntry  (ZipEntry  e  ) throws java.io.IOException;        public void  setComment  (String  comment  );        public void  setLevel  (int  level  );        public void  setMethod  (int  method  );  // Public Methods Overriding DeflaterOutputStream  public void  close  ( ) throws java.io.IOException;        public void  finish  ( ) throws java.io.IOException;        public void  write  (byte[ ]  b  , int  off  , int  len  ) throws java.io.IOException;  synchronized  } 

Subclasses

java.util.jar.JarOutput Stream