What is the life cycle of Java objects?

Java object life cycle includes: object creation, initialization, reachability, invalidation, and recycling. Objects are created through the new keyword, initialization is performed in the constructor, reachability refers to access through reference variables, invalidation refers to no longer reachable, and recycling refers to the garbage collector releasing the memory of the invalid object.

The life cycle of Java objects

Java objects go through the following stages in their life cycles:

1. Create a

• object first created through the new keyword.
• When the new keyword is executed, the JVM will allocate memory and call the object's constructor.

2. Initialization

• When the constructor is executed, the object will be initialized.
• This is the stage of setting the initial value of the object.

3. Reachability

• When an object is created, it is reachable.
• Reachability means that the object can be accessed through a reference variable.

4. Invalidation

• When an object is no longer reachable, it is considered invalid.
• Invalid objects are managed by the garbage collector (GC).

5. Recycling

• The garbage collector will reclaim the memory of expired objects.
• This helps prevent memory leaks and frees resources for use by new objects.

Practical case:

public class Person {
    private String name;
    private int age;

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    // ...
}

public class Main {
    public static void main(String[] args) {
        // 创建一个 Person 对象
        Person person = new Person("John", 30);

        // 对象可达并且可以访问
        System.out.println(person.name); // 打印 "John"

        // 将 person 引用赋值给 null，对象失活
        person = null;

        // 垃圾回收器将回收 person 对象使用的内存
    }
}

In this case, when the person reference is assigned the value null , the Person object will become invalid. The object's memory will then be reclaimed by the garbage collector.

The above is the detailed content of What is the life cycle of Java objects?. For more information, please follow other related articles on the PHP Chinese website!