Java FilterOutputStream flush()用法及代码示例

FilterOutputStream类flush()方法

• flush() 方法可在java.io包。
• flush() 方法用于刷新此 FilterOutputStream 并强制将字节从任何缓冲数据中写入 FilterInputStream。
• flush() 方法是一个非静态方法，它只能通过类对象访问，如果我们尝试使用类名访问方法，那么我们将得到一个错误。
• flush() 方法可能会在刷新流时抛出异常。
  IOException: 获取任何输入/输出错误时可能会抛出此异常。

用法:

    public void flush();

参数：

• 它不接受任何参数。

返回值：

该方法的返回类型是void，它什么都不返回。

例：

// Java program to demonstrate the example 
// of void flush() method of FilterInputStream

import java.io.*;

public class FlushOfFOS {
 public static void main(String[] args) throws Exception {
  FileInputStream fis_stm = null;
  FilterInputStream fil_stm = null;
  FileOutputStream fos_stm = null;
  FilterOutputStream fol_stm = null;

  int count = 0;

  try {
   // Instantiates FileOutputStream and 
   // FilterOutputStream
   fos_stm = new FileOutputStream("D:\\includehelp.txt");
   fol_stm = new BufferedOutputStream(fos_stm);

   // By using write() method is to
   // write byte to the fol_stm stream
   fol_stm.write(97);

   // By using flush() method is to
   // write bytes out to the basic 
   // output stream
   fol_stm.flush();

   // Instantiates FileInputStream and 
   // FilterInputStream
   fis_stm = new FileInputStream("C:\\Users\\Preeti Jain\\Desktop\\programs\\includehelp.txt");
   fil_stm = new BufferedInputStream(fis_stm);

   // Loop to read until available
   // bytes left
   while ((count = fil_stm.read()) != -1) {
    // Display corresponding bytes value
    char ch = (char) count;
    // Display value of b
    System.out.println("ch:" + ch);
   }
  } catch (Exception ex) {
   System.out.println(ex.toString());
  } finally {
   // with the help of this block is to
   // free all necessary resources linked
   // with the stream

   if (fis_stm != null) {
    fis_stm.close();

    if (fil_stm != null) {
     fil_stm.close();

     if (fol_stm != null) {
      fol_stm.close();

      if (fos_stm != null) {
       fos_stm.close();
      }
     }
    }
   }
  }
 }
}

输出

ch:a