java transient关键字

男娘i 2022-05-10 04:52 264阅读 0赞

当序列化实现Serializable这个接口时，transient修饰属性，用来表示不进行序列化。

举例：

实体类：

package com.xhx.java.javatransient.entity;
    
    
    import java.io.Serializable;
    
    public class User implements Serializable {
    
        private String name;
        private String gender;
    
        private transient String password;
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
        public String getGender() {
            return gender;
        }
    
        public void setGender(String gender) {
            this.gender = gender;
        }
    
        public String getPassword() {
            return password;
        }
    
        public void setPassword(String password) {
            this.password = password;
        }
    
        @Override
        public String toString() {
            return "User{" +
                    "name='" + name + '\'' +
                    ", gender='" + gender + '\'' +
                    ", password='" + password + '\'' +
                    '}';
        }
    }

把上面实体类写入文件中：

package com.xhx.java.javatransient;
    
    
    import com.xhx.java.javatransient.entity.User;
    
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.ObjectInputStream;
    import java.io.ObjectOutputStream;
    
    public class JavaTransientApplication {
    
        public static void main(String[] args) throws Exception {
            User user = new User();
            user.setName("xu");
            user.setGender("man");
            user.setPassword("abcdefg");
            String path = "/media/xuhaixing/java/myDocument/java/java-transient/src/main/java/aa.txt";
            ObjectOutputStream objectOutputStream = new ObjectOutputStream(new FileOutputStream(path));
            objectOutputStream.writeObject(user);
            objectOutputStream.close();
    
            ObjectInputStream objectInputStream = new ObjectInputStream(new FileInputStream(path));
            Object o = objectInputStream.readObject();
            objectInputStream.close();
    
            System.out.println(o);
            //transient 修饰后不可被通过Serializable接口的序列化
            //输出结果
            //User{name='xu', gender='man', password='null'}
    
        }
    }

如果实体类不实现Serializable会报下面错误：

Exception in thread "main" java.io.NotSerializableException: com.xhx.java.javatransient.entity.User
    	at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1184)
    	at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
    	at com.xhx.java.javatransient.JavaTransientApplication.main(JavaTransientApplication.java:20)
    Disconnected from the target VM, address: '127.0.0.1:33093', transport: 'socket'

执行结果输出如下：

User{name='xu', gender='man', password='null'}

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