testinputstream.java

本书是一本为Java学习者在基础内容学习结束后进行课程设计时提供参考的指导书

package apibook.c3.s1;

import java.io.*;

//测试InputStream类
public class TestInputStream {
  public TestInputStream(InputStream in) {
    try {
      System.out.println("execute read():" + (char)in.read());//读取第一个字符
      int availablenum = in.available();//查询可以读取的字节数
      System.out.println("available:" + in.available());
      if (in.markSupported())//查询是否支持mark和reset方法
      {
        in.mark(5);
        System.out.println("this input stream support mark");
      }
      else
        System.out.println("this input stream doesn't support mark");

      byte[] inbuf = new byte[10];
      int readsize = in.read(inbuf, 0, 10);//读取一个字节数组
      System.out.println("read number:" + readsize);
      System.out.println("read content:" + new String(inbuf));
      if (in.markSupported())
        in.reset();
      readsize = in.read(inbuf, 0, 10);//如果支持reset，对比结果
      System.out.println("read again number:" + readsize);
      System.out.println("read again content:" + new String(inbuf));

      in.close();//关闭
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
  public static void main(String[] args) {
    try {
      String filename = "TestInputStream.txt";//设定输入数据流文件
      TestInputStream testInputStream1 =
          new TestInputStream(new FileInputStream(filename));
    } catch (IOException e) {
        e.printStackTrace();
    }
  }

}