java中對象的序列化問題

dubbo接口中，傳遞的對象都是implements Serializable 接口的。今天改bug，我不當心把對象中的參數類型改了報錯了。

 

將person對象寫進文件中作測試。

package com.demo;

import java.io.Serializable;

public class Person implements Serializable {
	
	private static final long serialVersionUID = 1L;

	private String name;

	private String address;

	private Integer age;

	private int status = 0;

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}

	public Integer getAge() {
		return age;
	}

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

	public int getStatus() {
		return status;
	}

	public void setStatus(int status) {
		this.status = status;
	}

}

package com.demo;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OutputStream;

public class Test {
	
	private static File file = new File("obj.txt");

	public static void main(String[] args) {
		/*Person p1 = new Person();
		p1.setName("李四");
		p1.setAge(89);
		writeToFile(p1, file);*/
		
		Object obj = readToFile(file);
		Person p = (Person) obj;
		System.out.println(p.getAge());
	}
	
	public static void writeToFile(Object obj, File file){
		OutputStream out = null;
		ObjectOutputStream oos = null;
		try {
			out = new FileOutputStream(file);
			oos = new ObjectOutputStream(out);
			oos.writeObject(obj);
			oos.flush();
		} catch (Exception e) {
			e.printStackTrace();
		}finally{
			if(oos!=null){
				try {
					oos.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			if(out!=null){
				try {
					out.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}
	
	public static Object readToFile(File file){
		Object obj = null;
		FileInputStream fis = null;
		ObjectInputStream ois = null;
		try {
			fis = new FileInputStream(file);
			ois = new ObjectInputStream(fis);
			obj = ois.readObject();
		} catch (Exception e) {
			e.printStackTrace();
		}finally{
			if(fis!=null){
				try {
					fis.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
			
			if(ois!=null){
				try {
					ois.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
		return obj;
	}

}

person的age都爲Integer或int時，讀出/寫入都沒有問題。

寫入與讀出類型不一致時，就會報錯（java.io.InvalidClassException: com.demo.Person; incompatible types for field age）。

時間長了，忘記了包裝類與基本類型的區別了。