Java java.util.zip.Deflater.deflate()用法及代碼示例

描述

這個java.util.zip.Deflater.deflate(byte[] b, int off, int len, int flush)方法壓縮輸入數據並用壓縮數據填充指定的緩衝區。返回壓縮數據的實際字節數。

聲明

以下是聲明java.util.zip.Deflater.deflate(byte[] b, int off, int len, int flush)方法。

public int deflate(byte[] b, int off, int len, int flush)

參數

• b- 壓縮數據的緩衝區。

• off− 數據的起始偏移量。

• len− 壓縮數據的最大字節數。

• flush- 壓縮刷新模式。

返回

寫入輸出緩衝區的壓縮數據的實際字節數。

異常

• IllegalArgumentException− 如果刷新模式無效。

寫入輸出緩衝區的壓縮數據的實際字節數。

示例

下麵的例子展示了 java.util.zip.Deflater.deflate(byte[] b, int off, int len, int flush) 方法的用法。

package com.tutorialspoint;

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 TutorialsPoint.com;"
         +"Welcome to TutorialsPoint.com;"
         +"Welcome to TutorialsPoint.com;"
         +"Welcome to TutorialsPoint.com;"
         +"Welcome to TutorialsPoint.com;"
         +"Welcome to TutorialsPoint.com;"
         +"Welcome to TutorialsPoint.com;"
         +"Welcome to TutorialsPoint.com;"
         +"Welcome to TutorialsPoint.com;"
         +"Welcome to TutorialsPoint.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();
      deflater.setInput(input);
      deflater.finish();
      int compressedDataLength = deflater.deflate(output,0,output.length, Deflater.NO_FLUSH);
      deflater.end();

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

      // Decompress the bytes
      Inflater inflater = new Inflater();
      inflater.setInput(output, 0, compressedDataLength);
      byte[] result = new byte[1024];
      int resultLength = inflater.inflate(result);
      inflater.end();

      // Decode the bytes into a String
      message = new String(result, 0, resultLength, "UTF-8");
   
      System.out.println("UnCompressed Message length:" + message.length());
   }
}

讓我們編譯並運行上麵的程序，這將產生以下結果 -

Original Message length:300
Compressed Message length:42
UnCompressed Message length:300