java.io.InputStreamReader.ready() 方法通知此流是否已準備好被讀取。

聲明

以下是java.io.InputStreamReader.ready()方法的聲明：

public boolean ready()

參數

• NA

返回值

如果下一讀取保證不會阻塞輸入，該方法返回true，否則返回false。

異常

• IOException -- 如果發生I/ O錯誤

例子

下麵的示例演示java.io.InputStreamReader.ready()方法的用法。

package com.yiibai;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;

public class InputStreamReaderDemo {
   public static void main(String[] args) throws IOException {
      
      FileInputStream fis = null;
      InputStreamReader isr =null;
      boolean bool = false;
      int i;
      char c;
      
      try {
         // new input stream reader is created 
         fis = new FileInputStream("C:/test.txt");
         isr = new InputStreamReader(fis);
         
         // reads into the char buffer
         while((i=isr.read())!=-1)
         {
            // converts int to char
            c=(char)i;
            
            // prints the character
            System.out.println("Character read: "+c);
            
            // true if the next read is guaranteed
            bool = isr.ready();
            
            // prints
            System.out.println("Ready to read: "+bool);
         }
      } catch (Exception e) {
      
         // print error
         e.printStackTrace();
      } finally {
         
         // closes the stream and releases resources associated
         if(fis!=null)
            fis.close();
         if(isr!=null)
            isr.close();
      }   
   }
}

假設我們有一個文本文件c:/ test.txt，它具有以下內容。該文件將被用作輸入到我們的示例程序：

ABCDE

讓我們編譯和運行上麵的程序，這將產生以下結果：

Character read: A
Ready to read: true
Character read: B
Ready to read: true
Character read: C
Ready to read: true
Character read: D
Ready to read: true
Character read: E
Ready to read: false