java.util.zip.InflaterInputStream.markSupported()方法範例

java.util.zip.InflaterInputStream.markSupported()方法測試此輸入流是否支援mark()和reset()方法。 InflaterInputStream的markSupported方法返回false。

宣告

以下是java.util.zip.InflaterInputStream.markSupported()方法的宣告。

public boolean markSupported()

引數

• N/A

返回值

• 指示此流型別是否支援mark()和reset()方法的布林值。

異常

• IOException - 如果發生I/O錯誤。

範例

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

package com.yiibai;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.InflaterInputStream;

public class InflaterInputStreamDemo {
   public static void main(String[] args) throws DataFormatException, IOException {
      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");
      int length = message.length();
      // 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);
      System.out.println("Total uncompressed bytes input :" + deflater.getTotalIn());
      System.out.println("Compressed Message Checksum :" + deflater.getAdler());     
      deflater.finished();

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

      ByteArrayInputStream bin = new ByteArrayInputStream(output);
      InflaterInputStream inflaterInputStream = new InflaterInputStream(bin);
      byte[] result = new byte[1024];

      ByteArrayOutputStream buffer = new ByteArrayOutputStream();
      if(inflaterInputStream.markSupported()){
         inflaterInputStream.mark(0);  
      }
      if(inflaterInputStream.markSupported()){
         inflaterInputStream.reset();  
      }
      while(inflaterInputStream.available() != 0){
         buffer.write(inflaterInputStream.read());
      }

      inflaterInputStream.close();
      // Decode the bytes into a String
      String message1 = new String(buffer.toByteArray(),0, length,"UTF-8");
      System.out.println(message.equals(message1));
   }
}

執行上面範例程式碼，得到以下結果 -

Original Message length : 300
Total uncompressed bytes input :300
Compressed Message Checksum :368538129
Compressed Message length : 42
true