java高薪之路__005_IO流

参考地址：
1. http://blog.csdn.net/yczz/article/details/38761237

File类

ObjectInputStream  &&  ObjectOutputStream, 该流允许读取或写入用户自定义的类，但被读取或写入的类必须实现了Serializable接口 

DataInputStream  &&  DataOutputStream  有时没有必要存储整个对象的信息，而只是要存储一个对象的成员数据，成员数据的类型假设都是Java的基本数据类型，这样的需求不必使用到与Object输入、输出相关的流对象，可以使用DataInputStream、DataOutputStream来写入或读出数据
打算将Member类实例的成员数据写入文件中，并打算在读入文件数据后，将这些数据还原为Member对象。下面的代码简单示范了如何实现这个需求

package com.hxw.io;  

class Student implements Serializable{  
   private String name;  
   private int age;  
    
   public Student(String name, int age) {  
      super();  
      this.name = name;  
      this.age = age;  
   }  
   
   @Override  
   public String toString() {  
      return "Student [name=" + name + ", age=" + age + "]";  
   }  
    
    
}
   
import java.io.*;     
public class ObjetStream { 
   public static void main(String[] args) { 
      ObjectOutputStream objectwriter = null;  
      ObjectInputStream objectreader = null;  
       
      try {  
         objectwriter = new ObjectOutputStream(new FileOutputStream("D:/David/Java/java 高级进阶/files/student.txt"));  
         objectwriter.writeObject(new Student("gg", 22));  
         objectwriter.writeObject(new Student("tt", 18));  
         objectwriter.writeObject(new Student("rr", 17));  

         objectreader=new ObjectInputStream(new FileInputStream("D:/David/Java/java 高级进阶/files/student.txt"));  
         for (int i = 0; i < 3; i++) {  
            System.out.println(objectreader.readObject());  
         }  
      } catch (IOException | ClassNotFoundException e) {  
         // TODO自动生成的 catch 块  
         e.printStackTrace();  
      }finally{  
         try {  
            objectreader.close();  
            objectwriter.close();  
         } catch (IOException e) {  
            // TODO自动生成的 catch 块  
            e.printStackTrace();  
         }            
      }         
   }     
} 

package com.hxw;  
public class Member {  
    private String name;  
    private int age;  
    public Member() {  
    }  
   public Member(String name, int age) {  
        this.name = name;  
        this.age = age;  
    }  
    public void setName(String name){  
        this.name = name;  
    }  
    public void setAge(int age) {  
        this.age = age;  
    }  
    public String getName() {  
        return name;  
    }  
    public int getAge() {  
        return age;  
    }  
}  


import java.io.*;  
public class DataStreamDemo  
{  
    public static void main(String[]args)  
    {  
        Member[] members = {new Member("Justin",90),  
                new Member("momor",95),  
                new Member("Bush",88)};  
        try {  
            DataOutputStream dataOutputStream = new DataOutputStream(new FileOutputStream(args[0]));  

            for(Member member:members)  
            {  
                //写入UTF字符串  
                dataOutputStream.writeUTF(member.getName());  
                //写入int数据  
                dataOutputStream.writeInt(member.getAge());  
            }  

            //所有数据至目的地  
            dataOutputStream.flush();  
            //关闭流  
            dataOutputStream.close();  

            DataInputStream dataInputStream = new DataInputStream(new FileInputStream(args[0]));  

            //读出数据并还原为对象  
            for(int i=0;i<members.length;i++)  
            {  
                //读出UTF字符串  
                String name =dataInputStream.readUTF();  
                //读出int数据  
                int score =dataInputStream.readInt();  
                members[i] = new Member(name,score);  
            }  

            //关闭流  
            dataInputStream.close();  

            //显示还原后的数据  
            for(Member member : members)  
            {  
                System.out.printf("%s	%d%n",member.getName(),member.getAge());  
            }  
        }  
        catch(IOException e)  
        {  
            e.printStackTrace();  
        }  
    }  
}