java.io.Serializable 序列化问题
Person.java
package a.b.c; public class Person implements java.io.Serializable{ // private static final long serialVersionUID = 2481632967198330813L; String field1;
String field2;
String field3;
public String getField1() {
return field1;
}
public void setField1(String field1) {
this.field1 = field1;
}
public String getField2() {
return field2;
}
public void setField2(String field2) {
this.field2 = field2;
}
public String getField3() {
return field3;
}
public void setField3(String field3) {
this.field3 = field3;
} }
Student.java Student继承自Person,但为了清晰表示,按Person一模一样又覆盖了一遍
package a.b.c; public class Student extends Person implements java.io.Serializable { // private static final long serialVersionUID = 2481632967198330813L; String field1;
String field2;
String field3;
public String getField1() {
return field1;
}
public void setField1(String field1) {
this.field1 = field1;
}
public String getField2() {
return field2;
}
public void setField2(String field2) {
this.field2 = field2;
}
public String getField3() {
return field3;
}
public void setField3(String field3) {
this.field3 = field3;
} }
SerializableWriter.java
package a.b.c; import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream; public class SerializableWriter { public static void main(String[] args) throws Exception{
write();
} public static void write() throws Exception{
Student stu= new Student();
stu.setField1("aaa111");
stu.setField2("bbb222");
ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream("C:/Users/King/Desktop/jx.txt"));
objectOutputStream.writeObject(stu);
objectOutputStream.flush();
objectOutputStream.close();
} }
SerializableReader.java
package a.b.c; import java.io.FileInputStream;
import java.io.ObjectInputStream; public class SerializableReader { public static void main(String[] args) throws Exception{
read();
} public static void read() throws Exception{
ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream("C:/Users/King/Desktop/jx.txt"));
Object obj=objectInputStream.readObject();
Person person=(Person)obj;
System.out.println(person.getField1());
System.out.println(person.getField2());
objectInputStream.close();
} }
打印结果
aaa111
bbb222
总结
- 只要版本号一致,且Student就算删掉field3的属性和方法,仍旧可以把序列化后的Student反序列化成Student.
- 只要版本号一致,且Student 继承自父类 Person,那么就可以把序列化后的Student反序列化成Person.
自己项目经历:
esb_new.jar包中的head多加了一个password属性(这个场景是说添加属性的那个包就是新包)
然后生产上 核心 通过http连接 ESB(esb_old.jar) 去调用 电销(esb_new.jar)回调接口 ,报序列号版本不一致问题, 因为电销提供的回调接口是Spring Invoke远程方法调用,需要依赖请求对象RequestBusinessObjVo,在转对象时会用到序列化头部信息,此时旧包(esb_old.jar)丢了新包(esb_new.jar)需要的属性,所以旧包不能调新包.
但是电销(esb_new.jar)通过http连接 ESB(esb_old.jar)去调代理平台(esb_old.jar) 没报错. 是因为 电销 和ESB是http通信的,而ESB和代理平台此时通过Spring Invoke远程方法调用,仍旧用的是esb_old.jar包所以没有报序列号问号.