Java Java.io.ByteArrayInputStream markSupported() 方法

描述

如果输入流支持mark()和reset()方法调用，则java.io.ByteArrayInputStream.markSupported()对于ByteArrayInputStream该方法始终返回true 。

声明

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

 public boolean markSupported()

参数

不适用

返回值

此方法为ByteArrayInputStream返回true

异常

不适用

例子

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

 package com.jc2182; 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(); } } }

让我们编译并运行以上程序，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