Java 使用反射调用静态方法
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/2467544/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Invoking a static method using reflection
提问by Steven
I want to invoke the mainmethod which is static. I got the object of type Class, but I am not able to create an instance of that class and also not able to invoke the staticmethod main.
我想调用main静态方法。我得到了类型的对象Class，但我无法创建该类的实例，也无法调用该static方法main。
采纳答案by Adeel Ansari
// String.class here is the parameter type, that might not be the case with you
Method method = clazz.getMethod("methodName", String.class);
Object o = method.invoke(null, "whatever");
In case the method is private use getDeclaredMethod()instead of getMethod(). And call setAccessible(true)on the method object.
如果该方法是私人使用getDeclaredMethod()而不是getMethod(). 并调用setAccessible(true)方法对象。
回答by Frostman
String methodName= "...";
String[] args = {};
Method[] methods = clazz.getMethods();
for (Method m : methods) {
if (methodName.equals(m.getName())) {
// for static methods we can use null as instance of class
m.invoke(null, new Object[] {args});
break;
}
}
回答by atk
Fromthe Javadoc of Method.invoke():
来自 Method.invoke() 的 Javadoc：
If the underlying method is static, then the specified obj argument is ignored. It may be null.
如果底层方法是静态的，则指定的 obj 参数将被忽略。它可能为空。
What happens when you
当你
Class klass = ...; Method m = klass.getDeclaredMethod(methodName, paramtypes); m.invoke(null, args)
回答by Hari Krishna
public class Add {
static int add(int a, int b){
return (a+b);
}
}
In the above example, 'add' is a static method that takes two integers as arguments.
在上面的例子中，'add' 是一个静态方法，它接受两个整数作为参数。
Following snippet is used to call 'add' method with input 1 and 2.
以下代码段用于使用输入 1 和 2 调用“添加”方法。
Class myClass = Class.forName("Add");
Method method = myClass.getDeclaredMethod("add", int.class, int.class);
Object result = method.invoke(null, 1, 2);
Reference link.
参考链接。
