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;          }      }  }