Spring框架（一）

 1 <?xml version="1.0" encoding="UTF-8"?>
 2 <beans xmlns="http://www.springframework.org/schema/beans"
 3     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 4     xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
 5 
 6     <bean id="user" class="com.model.User">
 7     <!-- 通过Spring給类注入属性，通过空参构造方法 -->
 8         <property name="username">
 9             <value>hanqi</value>
10         </property>
11         <property name="password">
12             <value>123</value>
13         </property>    
14         
15         <!-- 
16         另一种通过带参构造方法
17         <constructor-arg index="0" value="name1"></constructor-arg>
18         <constructor-arg index="1" value="pwd1"></constructor-arg>     
19         -->
20     </bean>
21 
22 </beans>

 1 package com.model;
 2 
 3 public class User {
 4     private String username;
 5     private String password;
 6     
 7     
 8     
 9     public User() {
10         super();
11         System.out.println("调用User类的空参构造方法");
12         // TODO Auto-generated constructor stub
13     }
14     public User(String username, String password) {
15         super();
16         this.username = username;
17         this.password = password;
18         System.out.println("调用User类的带参构造方法 ");
19     }
20     public String getUsername() {
21         return username;
22     }
23     public void setUsername(String username) {
24         this.username = username;
25     }
26     public String getPassword() {
27         return password;
28     }
29     public void setPassword(String password) {
30         this.password = password;
31     }
32     @Override
33     public String toString() {
34         return "User [username=" + username + ", password=" + password + "]";
35     }
36     
37     
38     
39 }

 1 package com.test;
 2 
 3 import org.springframework.context.ApplicationContext;
 4 import org.springframework.context.support.ClassPathXmlApplicationContext;
 5 
 6 import com.model.User;
 7 
 8 public class Test {
 9     public static void main(String[] args) {
10         ApplicationContext ac=new ClassPathXmlApplicationContext("Spring-all.xml");//调用此方法时类已经实例化好了
11         User u=(User)ac.getBean("user");//拿到实例化的类，带有默认的值
12         
13         System.out.println(u);
14         ((ClassPathXmlApplicationContext)ac).close();
15         
16     }
17 }

 1 package com.test;
 2 
 3 import org.springframework.context.ApplicationContext;
 4 import org.springframework.context.support.ClassPathXmlApplicationContext;
 5 
 6 import com.model.User;
 7 
 8 public class Test {
 9     public static void main(String[] args) {
10         ApplicationContext ac=new ClassPathXmlApplicationContext("Spring-all.xml");//调用此方法时类已经实例化好了
11         
12         User u=(User)ac.getBean("user");//拿到实例化的类
13         
14         u.setUsername("u");
15         u.setPassword("p");
16         System.out.println(u);
17         ((ClassPathXmlApplicationContext)ac).close();
18         
19     }
20 }

 1 package com.test;
 2 
 3 import java.lang.reflect.Method;
 4 
 5 import com.model.User;
 6 
 7 public class Test2 {
 8     public static void main(String[] args) {
 9         try {
10             //实例化一个类，<?>代表可以是任何类型
11             Class<?> cla=Class.forName("com.model.User");
12             //cla.getConstructor(parameterTypes);获取类里的构造方法
13             //cla.getFields();//获取类里的成员变量
14             
15             //获得对象实例
16             User u=(User)cla.newInstance();
17             //u.setUsername("直接调用set设置的");
18             
19             //获取类里的所有方法
20             Method[] me=cla.getMethods();
21             
22             Object obj=null;
23             Object obj1=null;
24             
25             for(Method m:me){
26                 //找到方法，回调方法反射
27                 if("setUsername".equals(m.getName())){
28                     obj=m.invoke(u, "回调反射");
29                 }
30             }
31             for(Method m:me){
32                 if("getUsername".equals(m.getName())){
33                     obj1=m.invoke(u);
34                 }
35             }
36             //set方法没有返回值，打印null
37             System.out.println("setUsername方法的返回值:"+obj);
38             //直接打印对象，属性null
39             System.out.println("对象："+u);
40             //
41             System.out.println("getUsername方法的返回值:"+obj1);
42             
43         } catch (Exception e) {
44             // TODO Auto-generated catch block
45             e.printStackTrace();
46         }
47     }
48 }