Java 中的 Class getDeclaringClass()方法,带示例

原文:https://www . geesforgeks . org/class-getdeclaringclass-method-in-Java-with-examples/

Java . lang . classgetDeclaringClass() 方法用于获取该类的声明类。如果此类或接口是另一个类的成员,则方法返回此类的声明类。否则此方法返回 null。

语法:

public Constructor getDeclaringClass()

参数:此方法不接受任何参数。

返回值:如果这个类或接口是另一个类的成员,这个方法返回这个类的声明类。否则此方法返回 null。

异常如果有安全经理在场且不满足安全条件,此方法抛出安全异常

下面的程序演示了 getDeclaringClass()方法。

例 1:

// Java program to demonstrate getDeclaringClass() method

import java.util.*;

public class Test {
    public static void main(String[] args)
        throws ClassNotFoundException
    {

        // returns the Class object for this class
        Class myClass = Class.forName("Test");

        System.out.println("Class represented by myClass: "
                           + myClass.toString());

        // Get the declaring class of myClass
        // using getDeclaringClass() constructor
        System.out.println("DeclaringClass of myClass: "
                           + myClass.getDeclaringClass());
    }
}

输出:

Class represented by myClass: class Test
DeclaringClass of myClass: null

例 1:

// Java program to demonstrate getDeclaringClass() method

import java.util.*;

class Main {

    class Arr {
    };

    public Object obj;

    Main()
    {

        obj = new Arr();
    }

    public static void main(String[] args)
        throws ClassNotFoundException
    {
        Main t = new Main();

        // returns the Class object
        Class myClass = t.obj.getClass();

        // Get the declaring class of myClass
        // using getDeclaringClass() constructor
        System.out.println("DeclaringClass of myClass: "
                           + myClass.getDeclaringClass());
    }
}

输出:

DeclaringClass of myClass: class Main

参考:https://docs . Oracle . com/javase/9/docs/API/Java/lang/class . html # getDeclaringClass–