这里是准备使用的方法:

调用一个不带参数的方法:

public static void callMethodByName(Object object, String methodName) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
    object.getClass().getDeclaredMethod(methodName).invoke(object);
}

使用Arguments调用一个方法:

    public static void callMethodByName(Object object, String methodName, int i, String s) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
        object.getClass().getDeclaredMethod(methodName, int.class, String.class).invoke(object, i, s);
    }

使用上述方法如下:

package practice;

import java.io.IOException;
import java.lang.reflect.InvocationTargetException;

public class MethodInvoke {

    public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException, SecurityException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, IOException {
        String methodName1 = "methodA";
        String methodName2 = "methodB";
        MethodInvoke object = new MethodInvoke();
        callMethodByName(object, methodName1);
        callMethodByName(object, methodName2, 1, "Test");
    }

    public static void callMethodByName(Object object, String methodName) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
        object.getClass().getDeclaredMethod(methodName).invoke(object);
    }

    public static void callMethodByName(Object object, String methodName, int i, String s) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
        object.getClass().getDeclaredMethod(methodName, int.class, String.class).invoke(object, i, s);
    }

    void methodA() {
        System.out.println("Method A");
    }

    void methodB(int i, String s) {
        System.out.println("Method B: "+"\n\tParam1 - "+i+"\n\tParam 2 - "+s);
    }
}

输出:

Method A  
Method B:  
	Param1 - 1  
	Param 2 - Test

这里是准备使用的方法:

调用一个不带参数的方法:

public static void callMethodByName(Object object, String methodName) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
    object.getClass().getDeclaredMethod(methodName).invoke(object);
}

使用Arguments调用一个方法:

    public static void callMethodByName(Object object, String methodName, int i, String s) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
        object.getClass().getDeclaredMethod(methodName, int.class, String.class).invoke(object, i, s);
    }

使用上述方法如下:

package practice;

import java.io.IOException;
import java.lang.reflect.InvocationTargetException;

public class MethodInvoke {

    public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException, SecurityException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, IOException {
        String methodName1 = "methodA";
        String methodName2 = "methodB";
        MethodInvoke object = new MethodInvoke();
        callMethodByName(object, methodName1);
        callMethodByName(object, methodName2, 1, "Test");
    }

    public static void callMethodByName(Object object, String methodName) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
        object.getClass().getDeclaredMethod(methodName).invoke(object);
    }

    public static void callMethodByName(Object object, String methodName, int i, String s) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException {
        object.getClass().getDeclaredMethod(methodName, int.class, String.class).invoke(object, i, s);
    }

    void methodA() {
        System.out.println("Method A");
    }

    void methodB(int i, String s) {
        System.out.println("Method B: "+"\n\tParam1 - "+i+"\n\tParam 2 - "+s);
    }
}

输出:

Method A  
Method B:  
	Param1 - 1  
	Param 2 - Test

对于jooR，它仅仅是:

on(obj).call(methodName /*params*/).get()

这里有一个更详细的例子:

public class TestClass {

    public int add(int a, int b) { return a + b; }
    private int mul(int a, int b) { return a * b; }
    static int sub(int a, int b) { return a - b; }

}

import static org.joor.Reflect.*;

public class JoorTest {

    public static void main(String[] args) {
        int add = on(new TestClass()).call("add", 1, 2).get(); // public
        int mul = on(new TestClass()).call("mul", 3, 4).get(); // private
        int sub = on(TestClass.class).call("sub", 6, 5).get(); // static
        System.out.println(add + ", " + mul + ", " + sub);
    }
}

这个打印:

3, 12, 1

从通俗的角度来说，它应该是这样的:

java.lang.reflect.Method method;
try {
  method = obj.getClass().getMethod(methodName, param1.class, param2.class, ..);
} catch (SecurityException e) { ... }
  catch (NoSuchMethodException e) { ... }

参数确定你需要的非常具体的方法(如果有几个重载可用，如果方法没有参数，只给出methodName)。

然后通过调用调用该方法

try {
  method.invoke(obj, arg1, arg2,...);
} catch (IllegalArgumentException e) { ... }
  catch (IllegalAccessException e) { ... }
  catch (InvocationTargetException e) { ... }

同样，如果没有.invoke中的参数，请省略。但是是的。阅读Java反射

Method method = someVariable.class.getMethod(SomeClass);
String status = (String) method.invoke(method);

SomeClass是类，somvariable是变量。

Student.java

class Student{
    int rollno;
    String name;

    void m1(int x,int y){
        System.out.println("add is" +(x+y));
    }

    private void m3(String name){
        this.name=name;
        System.out.println("danger yappa:"+name);
    }
    void m4(){
        System.out.println("This is m4");
    }
}

StudentTest.java

import java.lang.reflect.Method;
public class StudentTest{

     public static void main(String[] args){

        try{

            Class cls=Student.class;

            Student s=(Student)cls.newInstance();


            String x="kichha";
            Method mm3=cls.getDeclaredMethod("m3",String.class);
            mm3.setAccessible(true);
            mm3.invoke(s,x);

            Method mm1=cls.getDeclaredMethod("m1",int.class,int.class);
            mm1.invoke(s,10,20);

        }
        catch(Exception e){
            e.printStackTrace();
        }
     }
}