Java Java.io.ByteArrayInputStream markSupported()用法及代码示例

描述

这个java.io.ByteArrayInputStream.markSupported() 如果输入流支持 mark() 和 reset() 方法调用，则方法返回 true。为了ByteArrayInputStream该方法总是返回true。

声明

以下是声明java.io.ByteArrayInputStream.markSupported()方法≫

public boolean markSupported()

参数

NA

返回值

此方法为 ByteArrayInputStream 返回 true

异常

NA

示例

下面的例子展示了 java.io.ByteArrayInputStream.markSupported() 方法的用法。

package com.tutorialspoint;

import java.io.ByteArrayInputStream;
import java.io.IOException;

public class ByteArratInputStreamDemo {
   public static void main(String[] args) throws IOException {
      byte[] buf = {65, 66, 67, 68, 69};
      ByteArrayInputStream bais = null;
      
      try {
         // create new byte array input stream
         bais = new ByteArrayInputStream(buf);
         
         // test support for mark() and reset() methods invocation
         boolean isMarkSupported = bais.markSupported();
         System.out.println("Is mark supported:"+isMarkSupported);
         System.out.println("Following is the proof:");
         
         // print bytes
         System.out.println("Byte read "+ bais.read());
         System.out.println("Byte read "+ bais.read());
         System.out.println("Byte read "+ bais.read());
         
         System.out.println("Mark() invocation");

         // mark() invocation;
         bais.mark(0);
         System.out.println("Byte read "+ bais.read());
         System.out.println("Byte read "+ bais.read());
         
         System.out.println("Reset() invocation");
         
         // reset() invocation
         bais.reset();
         System.out.println("Byte read "+ bais.read());
         System.out.println("Byte read "+ bais.read());
         
      } catch(Exception e) {
         // if I/O error occurs
         e.printStackTrace();
      } finally {
         if(bais!=null)
            bais.close();
      }   
   }
}

让我们编译并运行上面的程序，这将产生以下结果——

Is mark supported:true
Following is the proof:
Byte read 65
Byte read 66
Byte read 67
Mark() invocation
Byte read 68
Byte read 69
Reset() invocation
Byte read 68
Byte read 69