spring注入对象类型的属性

一.1.创建service类和Dao类

（1）在service中得到dao对象

2.具体实现过程

（1）在service里边把dao作为类型属性

（2）生成dao类型属性的set方法

public class UserDao {
    public void add(){
        System.out.println("dao--------------");
    }
}

public class UserService {
    private UserDao userDao;
    public void setUserDao(UserDao userDao) {
        this.userDao = userDao;
    }
    public void add(){
        System.out.println("service--------------");
        userDao.add();
    }
}

3.xml配置：

<bean id="userService" class="com.example.propetys.UserService">
<!-- name的值是 UserService类属性的值  ref是UserDao配置的ID的值-->
<property name="userDao" ref="userDao"></property>
</bean>
<bean id="userDao" class="com.example.propetys.UserDao"></bean>

  二：P名称空间注入

1.建一个类：

public class Person {
    private String pname;

    public void setPname(String pname) {
        this.pname = pname;
    }
    public void test(){
        System.out.println("asdhjcbsdj"+pname);
    }
}

2.xml文件<beans>下

xmlns:p="http://www.springframework.org/schema/p"

<bean id="person" class="com.example.propetys.Person" p:pname="lucy"></bean>

三.注入复杂类型属性

1.数组

2.list集合

3.map集合

4.properties类型

（1）建一个类

import java.util.List;
import java.util.Map;
import java.util.Properties;

public class Person {
    private String pname;

    public void setPname(String pname) {
        this.pname = pname;
    }
    private String[] arrs;
    private List<String> list;
    private Map<String, String> map;
    private Properties properties;
    
    public void setArrs(String[] arrs) {
        this.arrs = arrs;
    }
    public void setList(List<String> list) {
        this.list = list;
    }
    public void setMap(Map<String, String> map) {
        this.map = map;
    }
    public void setProperties(Properties properties) {
        this.properties = properties;
    }
    public void test(){
        System.out.println("arrs:"+arrs);
        System.out.println("list:"+list);
        System.out.println("map:"+map);
        System.out.println("properties:"+properties);
    }
}

（2）配置xml文件

<bean id="person" class="com.example.propetys.Person" >
<!-- 数组 -->
     <property name="arrs">
         <list>
            <value>数学</value>
            <value>语文</value>
            <value>历史</value>
            <value>英语</value>
         </list>
     </property>
<!-- list -->
      <property name="list">
         <list>
             <value>c/c++</value>
             <value>java</value>
         </list>
      </property>
<!-- map -->
      <property name="map">
        <map>
           <entry key="a" value="图书馆"></entry>
           <entry key="b" value="教学楼"></entry>
           <entry key="c" value="宿舍"></entry>
        </map>
      </property>
<!-- properties -->
     <property name="properties">
     <props>
       <prop key="driverclass">com.mysql.jdbc.Driver</prop>
       <prop key="username">root</prop>
     </props>
     </property>
</bean>