Java Java.io.BufferedOutputStream.flush()用法及代碼示例

描述

這個java.io.BufferedInputStream.flush()方法刷新緩衝的輸出字節以寫出底層輸出流。

聲明

以下是聲明java.io.BufferedOutputStream.flush()方法。

public void flush()

參數

NA

返回值

此方法不返回任何值。

異常

IOException− 如果發生 I/O 錯誤。

示例

下麵的例子展示了 java.io.BufferedOutputStream.flush() 方法的用法。

package com.tutorialspoint;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.IOException;

public class BufferedOutputStreamDemo {
   public static void main(String[] args) throws Exception {
      FileInputStream is = null;
      BufferedInputStream bis = null;
      ByteArrayOutputStream baos = null;
      BufferedOutputStream bos = null;
		
      try {
         // open input stream test.txt for reading purpose.
         is = new FileInputStream("c:/test.txt");

         // input stream is converted to buffered input stream
         bis = new BufferedInputStream(is);

         // creates a new byte array output stream
         baos = new ByteArrayOutputStream();

         // creates a new buffered output stream to write 'baos'
         bos = new BufferedOutputStream(baos);
		
         int value;

         // the file is read to the end
         while ((value = bis.read()) != -1) {
            bos.write(value);
         }

         // invokes flush to force bytes to be written out to baos
         bos.flush();

         // every byte read from baos
         for (byte b:baos.toByteArray()) {
            
            // converts byte to character
            char c = (char)b;
            System.out.print(c);
         }
      } catch(IOException e) {
         // if any IOException occurs 
         e.printStackTrace();
      } finally {
         // releases any system resources associated with the stream
         if(is!=null)
            is.close();
         if(bis!=null)
            bis.close();
         if(baos!=null)
            baos.close();
         if(bos!=null)
            bos.close();
      }	
   }
}

假設我們有一個文本文件c:/test.txt，其內容如下。該文件將用作我們示例程序的輸入 -

ABCDEFGHIJKLMNOPQRSTUVWXYZ 

讓我們編譯並運行上麵的程序，這將產生以下結果 -

ABCDEFGHIJKLMNOPQRSTUVWXYZ