java.io.CharArrayReader.markSupported() 如果方法測試數據流支持mark()。 char數組讀取器支持 mark()方法。

聲明

以下是java.io.CharArrayReader.markSupported()方法的聲明：

public boolean markSupported()

參數

• NA

返回值

如果流支持mark()調用該方法返回true。

異常

• NA

例子

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

package com.yiibai;

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();
      }
   }
}

讓我們來編譯和運行上麵的程序，這將產生以下結果：

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