spring对象属性的注入

注入:为对象的属性赋值

1.基本数据类型的set注入

public class User {
 private int userid;
 private String username;
 private String password;
}

 
为此类添加getter和setter
配置文件:

<bean id="user" class="com.dowebber.inject.User">
 <property name="userid" value="1"></property>
 <property name="password" value="pass_word"></property>
 <property name="username" value="tom"></property>
</bean>

 
测试类:

User user = (User)context.getBean("user");

 2.基本数据类型的构造器注入(构造方法)
为User添加构造方法
 

public User(String username, String password) {
  super();
  this.username = username;
  this.password = password;
 }
 
 public User(int userid, String username, String password) {
  super();
  this.userid = userid;
  this.username = username;
  this.password = password;
 }

 配置文件

<bean id="user" class="com.dowebber.inject.User">
 <constructor-arg value="1"></constructor-arg>
 <constructor-arg value="tom"></constructor-arg>
 <constructor-arg value="pass_word"></constructor-arg>
</bean>

 多构造器时应该指定参数顺序和类型

<constructor-arg value="1" type="int" index="0"></constructor-arg>
<constructor-arg value="tom" type="String" index="1"></constructor-arg>

 特殊类型数据的注入

public class Student {
 private int id;
 private String name;
 private String [] favor;
 private Set set;
 private List list;
 private Map map;
 private User user;
}

 添加setter 和getter

<!--数组的注入-->
 <property name="favor">
  <list>
   <value>上网</value>
   <value>足球</value>
  </list>
 </property>
<!--Set的注入-->
<property name="set">
  <set>
   <value>setvalue1</value>
   <value>setvalue2</value>
  </set>
</property>
<!--List的注入-->
 <property name="list">
  <list>
   <value>listvalue1</value>
   <value>listvalue2</value>
  </list>
 </property>
<!--Map的注入-->
 <property name="map">
  <map>
   <entry key="key1" value="value1"></entry>
   <entry key="key2" value="value2"></entry>
  </map>
 </property>

 
自定义类型对象的注入

<bean id="user" class="com.dowebber.inject.User">
 <constructor-arg value="1" type="int" index="0"></constructor-arg>
 <constructor-arg value="tom" type="String" index="1"></constructor-arg>
 <constructor-arg value="pass_word"></constructor-arg>
</bean>
 <property name="user" >
  <ref bean="user"/><!-- 也可以使用local="user" 不过这样的话,只能引用本配置文件中的Bean -->
 </property>

 

测试代码:

 public static void main(String[] args) {
  ApplicationContext context = new ClassPathXmlApplicationContext("com/dowebber/inject/spring.xml");
  
  Student std = (Student) context.getBean("student");
  
  System.out.println(std.getId());
  System.out.println(std.getName());
  System.out.println(std.getFavor().toString());
  System.out.println(std.getList());
  System.out.println(std.getSet());
  System.out.println(std.getMap());
  System.out.println(std.getUser());
 }