Java反射实例化对象和常规方法实例化对象

1.一个car类

package java_foundation.test_reflect;

public class Car {
 private String brand;
 private String color;
 private int maxSpeed;
 
 /**
  * 创建一个新的实例Car.
  *
  */
 public Car() {
  
 }

 
 /**
  * 创建一个新的实例Car.
  *
  * @param brand
  * @param color
  * @param maxSpeed
  */
 public Car(String brand, String color, int maxSpeed) {
  super();
  this.brand = brand;
  this.color = color;
  this.maxSpeed = maxSpeed;
 }
 
 public void introduce() {
  System.out.println("brand:"+brand+";color:"+color+";maxSpeed:"+maxSpeed);
 }

 public String getBrand() {
  return this.brand;
 }

 public void setBrand(String brand) {
  this.brand = brand;
 }

 public String getColor() {
  return this.color;
 }

 public void setColor(String color) {
  this.color = color;
 }

 public int getMaxSpeed() {
  return this.maxSpeed;
 }

 public void setMaxSpeed(int maxSpeed) {
  this.maxSpeed = maxSpeed;
 }
}

2.用两种方式实例化对象

package java_foundation.test_reflect;

import java.lang.reflect.Constructor;
import java.lang.reflect.Method;

@SuppressWarnings(value={"unchecked","rawtypes"})
public class RelectTest {

 /**
  * @creationDate. 2013-7-20 上午12:11:14
  * @param args
  */

 public static void main(String[] args) throws Throwable{
  // TODO Auto-generated method stub
  Car carA = initByCommon();
  carA.introduce();
  Car carB = initByDefaultConstructor();
  carB.introduce();
 }
 
 /**
  * 常规实例化对象
  * @creationDate. 2013-7-20 上午12:42:52
  * @return
  */
 public static Car initByCommon(){
  Car car = new Car();
  car.setBrand("红旗A");
  car.setColor("红色");
  car.setMaxSpeed(300);
  return car;
 }
 
 /**
  * 通过反射实例化对象
  * @creationDate. 2013-7-20 上午12:43:29
  * @return
  * @throws Throwable
  */
 public static Car initByDefaultConstructor() throws Throwable{
  // 获取类对象
  ClassLoader loader = Thread.currentThread().getContextClassLoader();
  Class clazz = loader.loadClass("java_foundation.test_reflect.Car");
  
  // 获取构造器对象
  Constructor cons = clazz.getDeclaredConstructor((Class[])null);
  // 获得实例化对象
  Car car = (Car)cons.newInstance();
  
  // 获得反射方法
  Method setBrand = clazz.getMethod("setBrand", String.class);
  // 调用实例对象的相应方法
  setBrand.invoke(car, "红旗B");
  
  // 同理
  Method setColor = clazz.getMethod("setColor", String.class);
  setColor.invoke(car, "黑色");
  
  // 同理
  Method setMaxSpeed = clazz.getMethod("setMaxSpeed", int.class);
  setMaxSpeed.invoke(car, 200);
  
  return car;
 }
}