包装类的学习

1）  用包装类进行数据传输

package IO;

import java.io.*;

public class DataStreamTest {

 

 

    public static void main(String[] args) throws Exception{

       FileOutputStream fos=new FileOutputStream("count.txt");//定义一个文件写入流

       BufferedOutputStream bos=new BufferedOutputStream(fos);//用缓冲类包装文件写入流

       DataOutputStream dos=new DataOutputStream(bos);//用包装类包装缓冲类

       dos.writeUTF("ab中国");//用utf格式向文件中写入信息

       dos.writeBytes("ab中国");

       dos.writeChars("ab中国");

       dos.close();//关闭文件输入流

      

       FileInputStream fis=new FileInputStream("count.txt");//定义一个文件输出流

       BufferedInputStream bis=new BufferedInputStream(fis);

       DataInputStream dis=new DataInputStream(bis);

       System.out.println(dis.readUTF());//以utf格式读取数据流

       byte []buf=new byte[1024];

       int len=dis.read(buf);

       System.out.println(new String(buf,0,len));

       dis.close();

    }

 

}

2）ObjectOutputStream和ObjectInputStream包装类的学习

package IO;

import java.io.*;

 

public class Serialization {

 

    public static void main(String[] args) throws Exception {

       Student stu1=new Student(19,"张三",25,"化学");//定义对象

       Student stu2=new Student(20,"李四",23,"物理");

       FileOutputStream fos=new FileOutputStream("student.txt");//定义输出流

       ObjectOutputStream os=new ObjectOutputStream(fos);//包装输出流，为对象的输出

       os.writeObject(stu1);//写入对象

       os.writeObject(stu2);

       os.close();//关闭输出流

      

       FileInputStream fis=new FileInputStream("student.txt");//定义输入流，读取文件

       ObjectInputStream is=new ObjectInputStream(fis);//定义输入类型为对象输入

       stu1=(Student)is.readObject();//用对象接收数据

       stu2=(Student)is.readObject();

       is.close();

       System.out.println("id:"+stu1.id);//打印对象信息

       System.out.println("name:"+stu1.name);

       System.out.println("age:"+stu1.age);

       System.out.println("department:"+stu1.department+"/n");

      

       System.out.println("id:"+stu2.id);

       System.out.println("name:"+stu2.name);

       System.out.println("age:"+stu2.age);

       System.out.println("department:"+stu2.department);

 

    }

 

}