可以像这样调用该方法。还有更多的可能性(检查反射api)，但这是最简单的一个:

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import org.junit.Assert;
import org.junit.Test;

public class ReflectionTest {

    private String methodName = "length";
    private String valueObject = "Some object";

    @Test
    public void testGetMethod() throws SecurityException, NoSuchMethodException, IllegalArgumentException,
            IllegalAccessException, InvocationTargetException {
        Method m = valueObject.getClass().getMethod(methodName, new Class[] {});
        Object ret = m.invoke(valueObject, new Object[] {});
        Assert.assertEquals(11, ret);
    }



}

对我来说，一个非常简单和愚蠢的方法是简单地创建一个方法调用者，就像这样:

public static object methodCaller(String methodName)
{
    if(methodName.equals("getName"))
        return className.getName();
}

然后当你需要调用这个方法时，简单地输入如下内容

//calling a toString method is unnessary here, but i use it to have my programs to both rigid and self-explanitory 
System.out.println(methodCaller(methodName).toString()); 

从反射使用方法调用:

Class<?> c = Class.forName("class name");
Method method = c.getDeclaredMethod("method name", parameterTypes);
method.invoke(objectToInvokeOn, params);

地点:

“class name”是类的名称 objectToInvokeOn类型为Object，是您希望在其上调用方法的对象 "method name"是你想要调用的方法的名称 parameterTypes的类型是Class[]，声明方法所接受的参数 params类型为Object[]，声明要传递给方法的参数

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

对于那些想要Java 7中简单的代码示例的人:

狗类:

package com.mypackage.bean;

public class Dog {
    private String name;
    private int age;

    public Dog() {
        // empty constructor
    }

    public Dog(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public void printDog(String name, int age) {
        System.out.println(name + " is " + age + " year(s) old.");
    }
}

ReflectionDemo类:

package com.mypackage.demo;

import java.lang.reflect.*;

public class ReflectionDemo {

    public static void main(String[] args) throws Exception {
        String dogClassName = "com.mypackage.bean.Dog";
        Class<?> dogClass = Class.forName(dogClassName); // convert string classname to class
        Object dog = dogClass.newInstance(); // invoke empty constructor

        String methodName = "";

        // with single parameter, return void
        methodName = "setName";
        Method setNameMethod = dog.getClass().getMethod(methodName, String.class);
        setNameMethod.invoke(dog, "Mishka"); // pass arg

        // without parameters, return string
        methodName = "getName";
        Method getNameMethod = dog.getClass().getMethod(methodName);
        String name = (String) getNameMethod.invoke(dog); // explicit cast

        // with multiple parameters
        methodName = "printDog";
        Class<?>[] paramTypes = {String.class, int.class};
        Method printDogMethod = dog.getClass().getMethod(methodName, paramTypes);
        printDogMethod.invoke(dog, name, 3); // pass args
    }
}

输出: 米什卡3岁了。

你可以用这种方法调用带形参的构造函数:

Constructor<?> dogConstructor = dogClass.getConstructor(String.class, int.class);
Object dog = dogConstructor.newInstance("Hachiko", 10);

或者，您可以删除

String dogClassName = "com.mypackage.bean.Dog";
Class<?> dogClass = Class.forName(dogClassName);
Object dog = dogClass.newInstance();

,做

Dog dog = new Dog();

Method method = Dog.class.getMethod(methodName, ...);
method.invoke(dog, ...);

推荐阅读:创建新类实例

对于那些在同一个类中调用非静态方法的方法，请参见下面的代码:

class Person {
    public void method1() {
        try {
            Method m2 = this.getClass().getDeclaredMethod("method2");
            m1.invoke(this);
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        }
    }

    public void method2() {
        // Do something
    }

}