Java:如何根据值返回不同的对象/数据类型

public Object getObjectByValue(int value) {
    if (value == 1) {
        return new String("Hello");
    } else if (value == 2) {
        return new Integer(100);
    } else {
        return null;
    }
}

public Object getObjectByValue(int value) {
    switch (value) {
        case 1:
            return new String("Hello");
        case 2:
            return new Integer(100);
        default:
            return null;
    }
}

public interface MyInterface {
    void doSomething();
}

public class MyFactory {
    public static MyInterface createObjectByValue(int value) {
        if (value == 1) {
            return new MyImplementation1();
        } else if (value == 2) {
            return new MyImplementation2();
        } else {
            return null;
        }
    }
}

public class MyImplementation1 implements MyInterface {
    public void doSomething() {
        System.out.println("Implementation 1");
    }
}

public class MyImplementation2 implements MyInterface {
    public void doSomething() {
        System.out.println("Implementation 2");
    }
}

MyInterface object = MyFactory.createObjectByValue(1);
object.doSomething(); // 输出：Implementation 1