Application scenario of the Invariant framework (Invariant) framework
Application scenario of the Invariant framework (Invariant) framework
Invariant is a very common concept in the Java class library, which is used to describe an object that is not affected by external state changes.In the constant framework, once the object is created, its state will not be modified again.This design mode can ensure the consistency and security of the object, and can reduce the complicated problems and the competitive conditions in the multi -threaded environment.
Application scenario:
1. Shared data in multi -threaded environment: In parallel programming, it is very important to unchanged objects.Because the unchanging object does not change its state, multiple threads can safely share the same constant object without need to perform additional synchronization operations.While improving performance and avoiding competition conditions, this also provides a method of simplifying concurrent programming complexity.
2. Capture mechanism: Non -changing objects are often used in cache mechanisms, which can relieve the frequently used objects in memory to avoid repeatedly created and destroy the expenses of objects.Because the object of the cache is immutable, other code cannot be modified, so it can return the cache object directly when used multiple times to improve the operating efficiency of the system.
3. Forced execution of unchanged semantics: Some classes need to ensure that their status is immutable to ensure the correctness and security of the program.The constant framework can be forced to execute unchanged semantics during the compilation and operation period to prevent misunderstanding from changing status.
Java code example:
public final class ImmutableObject {
private final String name;
private final int age;
public ImmutableObject(String name, int age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
}
public class Main {
public static void main(String[] args) {
ImmutableObject obj = new ImmutableObject("John", 30);
System.out.println ("name:" + obj.getName ()); // Output: name: John
System.out.println ("Age:" + Obj.getage ()); // Output: Age: 30
// Obj's status is unchanged. The following modification operation will cause compilation errors
// obj.setName("David");
// obj.setAge(40);
}
}
The above code example shows the use of an unchanging object.Member variables of the ImmutableObject class are declared as Final, and no way to modify its state.A ImmutableObject object was created in the main class, and its name and age information was exported, which also shows that the state of the object is immutable.
