Java ByteArrayInputStream markSupported()用法及代码示例

markSupported()方法是Java.io.ByteArrayInputStream方法的内置方法，用于测试此输入流是否支持mark和reset方法。 ByteArrayInputStreamInputStream的markSupported方法始终返回true

用法：

public boolean markSupported()

参数：该函数不接受任何参数。

返回值：该函数返回一个布尔值。如果此流实例支持mark和reset方法，则返回true，否则返回false。

下面是上述函数的实现：

示例1:

// Java program to implement 
// the above function 
import java.io.*; 
  
public class Main { 
    public static void main(String[] args) throws Exception 
    { 
  
        byte[] buf = { 5, 6, 7, 8, 9 }; 
  
        // Create new byte array input stream 
        ByteArrayInputStream exam 
            = new ByteArrayInputStream(buf); 
  
        // print bytes 
        System.out.println(exam.read()); 
        System.out.println(exam.read()); 
        System.out.println(exam.read()); 
  
        System.out.println("Mark() invocation"); 
  
        // Use of markSupported 
        boolean check = exam.markSupported(); 
        System.out.println("markSupported() : "
                           + check); 
  
        if (exam.markSupported()) { 
  
            // Use of reset() method : 
            // repositioning the stram to marked positions. 
            exam.reset(); 
  
            System.out.println("\nreset() invoked"); 
            System.out.println(exam.read()); 
            System.out.println(exam.read()); 
        } 
        else { 
            System.out.println("reset() method not supported."); 
        } 
    } 
}

输出：

5
6
7
Mark() invocation
markSupported() : true

reset() invoked
5
6

示例2:

// Java program to implement 
// the above function 
import java.io.*; 
  
public class Main { 
    public static void main(String[] args) throws Exception 
    { 
  
        byte[] buf = { 1, 2, 3 }; 
  
        // Create new byte array input stream 
        ByteArrayInputStream exam 
            = new ByteArrayInputStream(buf); 
  
        // print bytes 
        System.out.println(exam.read()); 
        System.out.println(exam.read()); 
        System.out.println(exam.read()); 
  
        // Use of markSupported 
        boolean check = exam.markSupported(); 
  
        System.out.println("markSupported() : "
                           + check); 
  
        if (exam.markSupported()) { 
  
            // Use of reset() method : 
            // repositioning the stram to marked positions 
            exam.reset(); 
  
            System.out.println("\nreset() invoked"); 
            System.out.println(exam.read()); 
            System.out.println(exam.read()); 
        } 
        else { 
            System.out.println("reset() method not supported."); 
        } 
    } 
}

输出：

1
2
3
markSupported() : true

reset() invoked
1
2

参考： https://docs.oracle.com/javase/10/docs/api/java/io/ByteArrayInputStream.html#markSupported()

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注：本文由纯净天空筛选整理自gopaldave大神的英文原创作品 ByteArrayInputStream markSupported() method in Java with Examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。