import java.io.DataOutputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;

public class DataOutputStream1 {
    public static void main(String[] args) {
        //创建一个数据输出流包装一个低级的字节输出流
        try (DataOutputStream dos=new DataOutputStream(new FileOutputStream("D:\\code\\weilai1\\src\\itheima.txt"));){
            dos.writeInt(97);
            dos.writeByte(99);
            dos.writeChar('中');
            dos.writeDouble(99.9);
            dos.writeUTF("世界，你好");
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}

 

import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;

public class DataInputStream1 {
    public static void main(String[] args) {

        try ( DataInputStream dis=  new DataInputStream (new FileInputStream
                ("D:\\code\\weilai1\\src\\itheima.txt"))){
            int a=dis.readInt();
            System.out.println(a);
            byte b=dis.readByte();
            System.out.println(b);
            char c= dis.readChar();
            System.out.println(c);
            double d= dis.readDouble();
            System.out.println(d);
            String rs= dis.readUTF();
            System.out.println(rs);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

序列化流

对象序列化：把对象写到Java文件中去

对象反序列化：把文件中的Java对象读出来

import java.io.DataOutputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;

public class DataOutputStream1 {
    public static void main(String[] args) {
        //创建一个数据输出流包装一个低级的字节输出流
        try (DataOutputStream dos=new DataOutputStream(new FileOutputStream("D:\\code\\weilai1\\src\\itheima.txt"));){
            dos.writeInt(97);
            dos.writeByte(99);
            dos.writeChar('中');
            dos.writeDouble(99.9);
            dos.writeUTF("世界，你好");
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}

 

import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;

public class DataInputStream1 {
    public static void main(String[] args) {

        try ( DataInputStream dis=  new DataInputStream (new FileInputStream
                ("D:\\code\\weilai1\\src\\itheima.txt"))){
            int a=dis.readInt();
            System.out.println(a);
            byte b=dis.readByte();
            System.out.println(b);
            char c= dis.readChar();
            System.out.println(c);
            double d= dis.readDouble();
            System.out.println(d);
            String rs= dis.readUTF();
            System.out.println(rs);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

import java.io.Serializable;
//注意：对象如果需要序列化，必须实现序列化接口
public class ObjectUser implements Serializable {
    private String loginname;
    private String username;
    private int age;
    //transient 这个成员变量将不参与序列化
    private  transient String password;

    public ObjectUser() {
    }

    public ObjectUser(String loginname, String username, int age, String password) {
        this.loginname = loginname;
        this.username = username;
        this.age = age;

        this.password = password;
    }

    public String getLoginname() {
        return loginname;
    }

    public void setLoginname(String loginname) {
        this.loginname = loginname;
    }

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }

    @Override
    public String toString() {
        return "ObjectUser{" +
                "loginname='" + loginname + '\'' +
                ", username='" + username + '\'' +
                ", age=" + age +
                ", password='" + password + '\'' +
                '}';
    }
}