Java通过反射调用方法详解编程语言

下面代码演示如何通过反射调用方法。

首先通过Class实例的getDeclaredMethods()获得所有方法的定义，然后通过Method的invoke方法触发方法调用，invoke方法的第一个参数是方法所属对象，第二个参数是方法调用的参数列表。

import java.lang.reflect.InvocationTargetException; 
import java.lang.reflect.Method; 
 
  
public class Main { 
 
    /** 
     * Invokes the methods of an object using the Reflection api. 
     */ 
    public void invokeMethodsUsingReflection() { 
 
        //Obtain the Class instance 
        Class computerClass = Computer.class; 
 
        //Get the methods 
        Method[] methods = computerClass.getDeclaredMethods(); 
 
        //Create the object that we want to invoke the methods on 
        Computer computer = new Computer(); 
 
        //Loop through the methods and invoke them 
        for (Method method : methods) { 
            Object result; 
            try { 
                //Call the method. Since none of them takes arguments we just 
                //pass an empty array as second parameter. 
                result = method.invoke(computer, new Object[0]); 
            } catch (IllegalArgumentException ex) { 
                ex.printStackTrace(); 
                return; 
            } catch (InvocationTargetException ex) { 
                ex.printStackTrace(); 
                return; 
            } catch (IllegalAccessException ex) { 
                ex.printStackTrace(); 
                return; 
            } 
            System.out.println(method.getName() + ": " + result); 
        } 
    } 
 
    /** 
     * @param args the command line arguments 
     */ 
    public static void main(String[] args) { 
        new Main().invokeMethodsUsingReflection(); 
    } 
 
    class Computer { 
 
        private String brand = "DELL"; 
        private String type = "Laptop"; 
        private int harddiskSize_GB = 300; 
        private boolean AntiVirusInstalled = true; 
 
        public String getBrand() { 
            return brand; 
        } 
 
        public String getType() { 
            return type; 
        } 
 
        public int getHarddiskSize_GB() { 
            return harddiskSize_GB; 
        } 
 
        public boolean isAntiVirusInstalled() { 
            return AntiVirusInstalled; 
        } 
    } 
}