JavaZip Deflater.needsInput() 方法

package com.codingdict;



import java.io.UnsupportedEncodingException;

import java.util.zip.DataFormatException;

import java.util.zip.Deflater;

import java.util.zip.Inflater;



public class DeflaterDemo {

   public static void main(String[] args) 

      throws DataFormatException, UnsupportedEncodingException {

      String message = "Welcome to codingdict.com;"

         +"Welcome to codingdict.com;"

         +"Welcome to codingdict.com;"

         +"Welcome to codingdict.com;"

         +"Welcome to codingdict.com;"

         +"Welcome to codingdict.com;"

         +"Welcome to codingdict.com;"

         +"Welcome to codingdict.com;"

         +"Welcome to codingdict.com;"

         +"Welcome to codingdict.com;";

      System.out.println("Original Message length : " + message.length());

      byte[] input = message.getBytes("UTF-8");

      // Compress the bytes

      byte[] output = new byte[1024];



      Deflater deflater = new Deflater();

      int inCount = input.length;  

      int inPosition = 0;

      int outPosition = 0;



      int MAX_BUFFER_SIZE = 10;

      while(!deflater.finished()){

         int want = -1;

         int got;

         if (deflater.needsInput() && inCount != 0) {

            want = (inCount < MAX_BUFFER_SIZE) ? inCount : MAX_BUFFER_SIZE;



            deflater.setInput(input, inPosition, want);



            inCount -= want;

            inPosition += want;

            if (inCount == 0) {

               deflater.finish();

            }

         }

         // deflate to current position in output buffer

         int compCount;



         compCount = deflater.deflate(output, outPosition, MAX_BUFFER_SIZE);

         outPosition += compCount;

      }



      System.out.println("Total uncompressed bytes output :" + deflater.getTotalOut());     

      System.out.println("Compressed Message Checksum :" + deflater.getAdler());     

      deflater.finished();



      System.out.println("Compressed Message length : " + outPosition);



      // Decompress the bytes

      Inflater inflater = new Inflater();

      inflater.setInput(output, 0, outPosition);

      byte[] result = new byte[1024];

      int resultLength = inflater.inflate(result);

      inflater.finished();



      // Decode the bytes into a String

      message = new String(result, 0, resultLength, "UTF-8");

      System.out.println("UnCompressed Message Checksum :" + inflater.getAdler());  

      System.out.println("UnCompressed Message length : " + message.length());

   }

}