java.util.zip.Deflater.deflate() 方法示例

描述

java.util.zip.Deflater.deflate(byte[] b) 方法壓縮輸入資料，並用壓縮資料填充指定緩衝區。返回實際壓縮資料位元組數。值為 0 則表示呼叫 needsInput 來確定是否需要更多輸入資料。

宣告

以下是 java.util.zip.Deflater.deflate(byte[] b) 方法的宣告：

public int deflate(byte[] b)

引數

• b − 用於存放壓縮資料的緩衝區。

返回

寫入輸出緩衝區的實際壓縮資料位元組數。

示例

以下示例顯示瞭如何使用 java.util.zip.Deflater.deflate(byte[] b) 方法：

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);
      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());
   }
}

讓我們編譯並執行上述程式，將生成以下結果 -

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