2.Sprng-IoC-Java反射例子

1.Car.java

 1 package com.jike.spring.chapter03.reflect;
 2
 3 public class Car {
 4     private String brand;
 5
 6     private String color;
 7
 8     private int maxSpeed;
 9
10     //1.默认构造函数
11     public Car(){
12         System.out.println("init car!!");
13         }
14
15     //2.带参构造函数
16     public Car(String brand,String color,int maxSpeed){
17         this.brand = brand;
18         this.color = color;
19         this.maxSpeed = maxSpeed;
20     }
21
22     //3.未带参的方法
23     public void introduce() {
24        System.out.println("brand:"+brand+";color:"+color+";maxSpeed:"+maxSpeed);
25     }
26
27     public String getBrand() {
28         return brand;
29     }
30
31     public void setBrand(String brand) {
32         this.brand = brand;
33     }
34
35     public String getColor() {
36         return color;
37     }
38
39     public void setColor(String color) {
40         this.color = color;
41     }
42
43     public int getMaxSpeed() {
44         return maxSpeed;
45     }
46
47     public void setMaxSpeed(int maxSpeed) {
48         this.maxSpeed = maxSpeed;
49     }
50 }

2.ReflectTest.java

 1 package com.jike.spring.chapter03.reflect;
 2
 3 import java.lang.reflect.Constructor;
 4 import java.lang.reflect.Method;
 5
 6
 7 public class ReflectTest {
 8
 9
10     public static Car  initByDefaultConst() throws Throwable
11     {
12         //1.通过类装载器获取Car类对象
13         ClassLoader loader = Thread.currentThread().getContextClassLoader();
14         Class clazz = loader.loadClass("com.jike.spring.chapter03.reflect.Car");
15
16         //2.获取类的默认构造器对象并实例化Car
17         Constructor cons = clazz.getDeclaredConstructor((Class[])null);
18         Car car = (Car)cons.newInstance();
19
20         //3.通过反射方法设置属性
21         Method setBrand = clazz.getMethod("setBrand",String.class);
22         setBrand.invoke(car,"奔驰");
23         Method setColor = clazz.getMethod("setColor",String.class);
24         setColor.invoke(car,"黑色");
25         Method setMaxSpeed = clazz.getMethod("setMaxSpeed",int.class);
26         setMaxSpeed.invoke(car,200);
27         return car;
28     }
29
30     public static Car initByParamConst()  throws Throwable{
31         //1.通过类装载器获取Car类对象
32         ClassLoader loader = Thread.currentThread().getContextClassLoader();
33         Class clazz = loader.loadClass("com.jike.spring.chapter03.reflect.Car");
34
35         //2.获取类的带有参数的构造器对象
36         Constructor cons = clazz.getDeclaredConstructor(new Class[]{String.class,String.class,int.class});
37
38         //3.使参数的构造器对象实例化Car
39         Car car = (Car)cons.newInstance(new Object[]{"宝马","红色",180});
40         return car;
41     }
42
43     public static void main(String[] args) throws Throwable {
44         Car car1 = initByDefaultConst();
45         Car car2 = initByParamConst();
46         car1.introduce();
47         car2.introduce();
48     }
49 }