Java CharArrayReader mark()方法

java.io.CharArrayReader.mark(int readAheadLimit) 用于标记流中的当前位置。调用reset()会将流重新定位。

1 语法

public void mark(int readAheadLimit)

2 参数

readAheadLimit：参数设置保留标记时可以读取的字符数限制。由于实际上没有限制，因为流的输入来自字符数组，因此通常会忽略该参数。

3 返回值

无

4 示例 

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * java.io.CharArrayReader.mark(int readAheadLimit)方法的例子
 */
import java.io.CharArrayReader;
import java.io.IOException;

public class Demo {
    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);

            // 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
            System.out.print("Stream is already closed");
        } finally {
            // releases any system resources associated with the stream
            if(car!=null)
                car.close();
        }
    }
}

输出结果为：

65
66
Mark() is invoked
67
68
Reset() is invoked
67
68
69