如何从Java中的类名获取类对象

I know the class name, say "MyClass" and want to retrieve the Class object, ie. MyClass.class for future references. Is there a way to do that?

我知道类名，说“MyClass”并想要检索Class对象，即。 MyClass.class以供将来参考。有没有办法做到这一点？

I've looked through the web but most of the things I found related to it were about the ClassLoader, which I presume are not suitable for my case. I do not want to initialize a class, but only get a class object for future uses.

我已经浏览了网页，但我发现的大部分内容都与ClassLoader有关，我认为这不适合我的情况。我不想初始化一个类，但只获取一个类对象以供将来使用。

EDIT: Regarding the first answers to this:

编辑：关于这个的第一个答案：

I've already checked the forName() method but I thought that is supposed to also initialize the class. Now I can call it with the full arguments and pass false to the second argument, but would the third have to be null or what?

我已经检查了forName（）方法，但我认为这也应该初始化类。现在我可以使用完整的参数调用它并将false传递给第二个参数，但第三个参数必须为null或者是什么？

Would

将

Class.forName("MyClass", false, null);

return MyClass.class?

返回MyClass.class？

In fact, what I want to do, is replace an array of String IDs associated with Class objects, with an array of IDs from which the class objects are fetched automatically, to get rid of some manual work :)

事实上，我想要做的是替换与Class对象关联的String ID数组，以及从中自动获取类对象的ID数组，以摆脱一些手动工作:)

Thanks for the quick answers and sorry for not mentioning this before.

感谢您的快速回答，并且抱歉之前没有提及此问题。

4 个解决方案

#1

You can use:

您可以使用：

Class c = Class.forName("com.package.MyClass");

And later instantiate an object:

然后实例化一个对象：

Object obj = c.newInstance();

EDIT: This is just the simplest use case. As indicated in the comments, you will need to consider constructor arguments and exceptions thrown by the initialization process. The JavaDocs for newInstance has all the details.

编辑：这只是最简单的用例。如注释中所示，您将需要考虑初始化过程抛出的构造函数参数和异常。 newInstance的JavaDocs具有所有细节。

#2

Class.forName("MyClass")

Read the JavaDoc for details

阅读JavaDoc以获取详细信息

#3

It sounds like you might be able to use the Class class's static forName method.

听起来您可能能够使用Class类的静态forName方法。

#4

It's also worth noting that the above suggestions are correct, but will only work for default (parameterless) constructors. You could also do something like:

值得注意的是，上述建议是正确的，但仅适用于默认（无参数）构造函数。你也可以这样做：

    public Object newInstance(String className, Object...args) throws Exception {
        Class<?> clazz = Class.forName(className);
        if(args == null || args.length == 0) {
            return clazz.newInstance();
        }

        List<Class<?>> argTypes = new ArrayList<Class<?>>();
        for(Object object : args) {
            argTypes.add(object.getClass());
        }
        Constructor<?> explicitConstructor = clazz.getConstructor(argTypes.toArray(new Class[argTypes.size()]));
        return explicitConstructor.newInstance(args);
    }

#1