java.util.zip.DeflaterOutputStream.flush() 方法示例

描述

java.util.zip.DeflaterOutputStream.flush() 方法重新整理壓縮輸出流。如果在構建此壓縮輸出流時 syncFlush 為 true，則此方法首先使用重新整理模式Deflater.SYNC_FLUSH，讓底層壓縮器重新整理全部待處理的資料以將其強制重新整理到輸出流，然後重新整理輸出流。否則，此方法只重新整理輸出流而不重新整理壓縮器。

宣告

以下是 java.util.zip.DeflaterOutputStream.flush() 方法的宣告。

public void flush()
   throws IOException

異常

• IOException − 如果發生 I/O 錯誤。

示例

以下示例顯示了 java.util.zip.DeflaterOutputStream.flush() 方法的用法。

package com.tutorialspoint;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.Arrays;
import java.util.zip.Adler32;
import java.util.zip.CheckedInputStream;
import java.util.zip.DataFormatException;
import java.util.zip.Deflater;
import java.util.zip.DeflaterInputStream;
import java.util.zip.DeflaterOutputStream;
import java.util.zip.Inflater;
import java.util.zip.InflaterInputStream;

public class DeflaterOutputStreamDemo {

   public static void main(String[] args) throws DataFormatException, IOException {
      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;";
      String dictionary = "Welcome";
      System.out.println("Original Message length : " + message.length());
      byte[] input = message.getBytes("UTF-8");

      // Compress the bytes
      ByteArrayOutputStream arrayOutputStream = new ByteArrayOutputStream();
      DeflaterOutputStream outputStream = new DeflaterOutputStream(arrayOutputStream);
      outputStream.write(input);
      outputStream.flush();
      outputStream.close();

      //Read and decompress the data
      byte[] readBuffer = new byte[5000];
      ByteArrayInputStream arrayInputStream = 
         new ByteArrayInputStream(arrayOutputStream.toByteArray());
      InflaterInputStream inputStream = new InflaterInputStream(arrayInputStream);
      int read = inputStream.read(readBuffer);

      //Should hold the original (reconstructed) data
      byte[] result = Arrays.copyOf(readBuffer, read);

      // Decode the bytes into a String
      message = new String(result, "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
UnCompressed Message length : 300