2.8serialVersionUID&transient【应用】
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serialVersionUID
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用对象序列化流序列化了一个对象后，假如我们修改了对象所属的类文件，读取数据会不会出问题呢？
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会出问题，会抛出InvalidClassException异常
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如果出问题了，如何解决呢？
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重新序列化
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给对象所属的类加一个serialVersionUID
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private static final long serialVersionUID = 42L;
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transient
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如果一个对象中的某个成员变量的值不想被序列化，又该如何实现呢？
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给该成员变量加transient关键字修饰，该关键字标记的成员变量不参与序列化过程
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示例代码
package duixiangxuliehua;import java.io.Serial;
import java.io.Serializable;public class Student implements Serializable {@Serial// 显示序列化idprivate static final long serialVersionUID = 42L;private String name;// private int age;// 不参与序列化private transient int age;public Student() {}public Student(String name, int age) {this.name = name;this.age = age;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}/* @Overridepublic String toString() {return "Student{" +"name='" + name + '\'' +", age=" + age +'}';}*/
}
package duixiangxuliehua;import java.io.*;public class demo1 {public static void main(String[] args) throws IOException, ClassNotFoundException {// write();read();}public static void write() throws IOException {ObjectOutputStream oo = new ObjectOutputStream(new FileOutputStream("stu\\src\\duixiangxuliehua\\demo.txt"));Student s = new Student("林青霞",30);oo.writeObject(s);oo.close();}public static void read() throws IOException, ClassNotFoundException {ObjectInputStream ois = new ObjectInputStream(new FileInputStream("stu\\src\\duixiangxuliehua\\demo.txt"));Object o = ois.readObject();Student s = (Student) o;System.out.println(s.getName()+s.getAge());ois.close();}
}