Java ObjectOutputStream drain()用法及代碼示例

ObjectOutputStream類drain()方法

• drain() 方法可在java.io包。
• drain() 方法用於排出此 ObjectOutputStream 中的任何緩衝內容。
• drain() 方法是一個非靜態方法，它隻能通過類對象訪問，如果我們嘗試使用類名訪問方法，那麽我們將得到一個錯誤。
• drain() 方法可能會在排空緩衝數據時拋出異常。
  IOException:當從輸出流寫入時出現任何輸入/輸出錯誤時，可能會拋出此異常。

用法:

    protected void drain();

參數：

• 它不接受任何參數。

返回值：

該方法的返回類型是void，它什麽都不返回。

例：

// Java program to demonstrate the example 
// of void drain() method of
// ObjectOutputStream

import java.io.*;

public class Drain extends ObjectOutputStream {
 public Drain(OutputStream os) throws IOException {
  super(os);
 }

 public static void main(String[] args) throws Exception {
  // Instantiates ObjectOutputStream , ObjectInputStream 
  // FileInputStream and FileOutputStream
  FileOutputStream file_out_stm = new FileOutputStream("D:\\includehelp.txt");
  Drain obj_out_stm = new Drain(file_out_stm);
  FileInputStream file_in_stm = new FileInputStream("D:\\includehelp.txt");
  ObjectInputStream obj_in_stm = new ObjectInputStream(file_in_stm);

  // By using writeObject() method is to
  // write the object to the stream		
  obj_out_stm.writeInt(156924);

  // By using drain() method is to
  // drain the stream
  obj_out_stm.drain();

  // By using readObject() method is to 
  // read the object
  int in = (int) obj_in_stm.readInt();
  System.out.println("obj_in_stm.readInt():" + in );

  // By using close() method is to 
  // close all the streams 
  System.out.println("Stream Shutdown... ");

  file_in_stm.close();
  file_out_stm.close();
  obj_in_stm.close();
  obj_out_stm.close();
 }
}

輸出

obj_in_stm.readInt():156924
Stream Shutdown...