Java Java.io.CharArrayReader.markSupported() 方法

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  描述

  java.io.CharArrayReader.markSupported()方法测试流是否支持mark()。字符数组读取器支持mark()方法。
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  声明

  以下是java.io.CharArrayReader.markSupported()方法的声明-

   public boolean markSupported()

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  参数

  不适用
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  返回值

  如果流支持mark()调用，则该方法返回true。
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  异常

  不适用
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  例子

  以下示例显示java.io.CharArrayReader.markSupported()方法的用法。

   
  package com.jc2182;
  import java.io.CharArrayReader;
  import java.io.IOException;
  
  public class CharArrayReaderDemo {
     public static void main(String[] args) {      CharArrayReader car = null;
        char[] ch = {'A', 'B', 'C', 'D', 'E'};
  
        try {
           // create new character array reader
           car = new CharArrayReader(ch);
           
           // verifies if the stream support mark() method
           boolean bool = car.markSupported();
           System.out.println("Is mark supported : "+bool);
           System.out.println("Proof:");
           
           // read and print the characters from the stream
           System.out.println(car.read());
           System.out.println(car.read());
           
           // mark() is invoked at this position
           car.mark(0);
           System.out.println("Mark() is invoked");
           System.out.println(car.read());
           System.out.println(car.read());
           
           // reset() is invoked at this position
           car.reset();
           System.out.println("Reset() is invoked");
           System.out.println(car.read());
           System.out.println(car.read());
           System.out.println(car.read());
           
        } catch(IOException e) {
           // if I/O error occurs
           e.printStackTrace();
        } finally {
           // releases any system resources associated with the stream
           if(car!=null)
              car.close();
        }
     }
  }
  

  让我们编译并运行以上程序，这将产生以下结果-

   
  Is mark supported : true
  Proof:
  65
  66
  Mark() is invoked
  67
  68
  Reset() is invoked
  67
  68
  69