java.util.zip.Deflater.getAdler()方法範例

java.util.zip.Deflater.getAdler()方法返回未壓縮資料的ADLER-32值。

宣告

以下是java.util.zip.Deflater.getAdler()方法的宣告。

public int getAdler()

引數

• N/A

返回值

• 未壓縮資料的ADLER-32值。

範例

以下範例顯示了java.util.zip.Deflater.getAdler()方法的用法。

package com.yiibai;

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 Tw511.com;"
         +"Welcome to Tw511.com;"
         +"Welcome to Tw511.com;"
         +"Welcome to Tw511.com;"
         +"Welcome to Tw511.com;"
         +"Welcome to Tw511.com;"
         +"Welcome to Tw511.com;"
         +"Welcome to Tw511.com;"
         +"Welcome to Tw511.com;"
         +"Welcome to Tw511.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);
      System.out.println("Compressed Message Checksum :" + deflater.getAdler());
      deflater.finished();

      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.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());
   }
}

執行上面範例程式碼，得到以下結果 -

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