1. WIKI教程
2. Java.io包
3. boolean markSupported()

boolean markSupported()

描述 (Description)

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

声明 (Declaration)

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

public boolean markSupported()

参数 (Parameters)

NA

返回值 (Return Value)

对于ByteArrayInputStream，此方法返回true

异常 (Exception)

NA

例子 (Example)

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

package com.iowiki;
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