void flush

描述

所述java.io.BufferedWriter.flush（）方法从写入缓冲器以作为预期目的地的字符或字节流刷新字符。

声明

以下是 java.io.BufferedWriter.flush（） 方法的声明。

public Writer flush()

参数

NA

返回值

此方法不返回任何值。

异常

IOException - 如果发生I / O错误。

实例

以下示例显示了java.io.BufferedWriter.flush（）方法的用法。

package com.tutorialspoint;

  import java.io.BufferedWriter;
  import java.io.IOException;
  import java.io.StringWriter;

  public class BufferedWriterDemo {
     public static void main(String[] args) throws IOException {
        StringWriter sw = null;
        BufferedWriter bw = null;
        String letters = "ABCDEFGHIJK";

        try {
           // create string writer
           sw = new StringWriter();

           //create buffered writer
           bw = new BufferedWriter(sw);

           // for each character in the string
           for (char c: letters.toCharArray()) {

              // append character to the writer
              bw.append(c);

              // flush the characters to the intended stream
              bw.flush();

              // print string buffer from string writer
              System.out.println(sw.getBuffer());
           }
        } catch(IOException e) {
           // if I/O error occurs
           e.printStackTrace();
        } finally {
           // releases any system resources associated with the stream
           if(sw!=null)
              sw.close();
           if(bw!=null)
              bw.close();
        }
     }
  }

让我们编译并运行上面的程序，这将产生以下结果

A
  AB
  ABC
  ABCD
  ABCDE
  ABCDEF
  ABCDEFG
  ABCDEFGH
  ABCDEFGHI
  ABCDEFGHIJ
  ABCDEFGHIJK