使用类名和调用构造函数创建实例 [英] Creating an instance using the class name and calling constructor

问题描述

有没有办法根据类名(动态)创建特定类的实例并将参数传递给其构造函数.

Is there a way to create an instance of a particular class given the class name (dynamic) and pass parameters to its constructor.

类似于:

Object object = createInstance("mypackage.MyClass","MyAttributeValue");

其中 "MyAttributeValue" 是 MyClass 的构造函数的参数.

Where "MyAttributeValue" is an argument to the constructor of MyClass.

推荐答案

是的，例如:

Class<?> clazz = Class.forName(className);
Constructor<?> ctor = clazz.getConstructor(String.class);
Object object = ctor.newInstance(new Object[] { ctorArgument });

这当然只适用于单个字符串参数，但您可以很容易地修改它.

That will only work for a single string parameter of course, but you can modify it pretty easily.

请注意，类名必须是完全限定的，即包括命名空间.对于嵌套类，您需要使用美元(因为这是编译器使用的).例如:

Note that the class name has to be a fully-qualified one, i.e. including the namespace. For nested classes, you need to use a dollar (as that's what the compiler uses). For example:

package foo;

public class Outer
{
    public static class Nested {}
}

要为此获得 Class 对象，您需要 Class.forName("foo.Outer$Nested").

To obtain the Class object for that, you'd need Class.forName("foo.Outer$Nested").

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