八.Spring的属性注入注入对象,复杂的集合类型属性

在上一篇博客上,用字符串类型的属性简单的介绍了下Spring的属性注入,这片文章会介绍更高级的属性注入.

属性注入-注入对象类型

场景介绍:我们现在要做一个新增用户的操作.
在不使用Spring类开发时,我们传统的开发应该是UserService通过UserDao来操作数据库实现对User的新增,代码如下.
传统的开发:

package cn.com.yves.spring;public class UserDao {public void addUser() {System.out.println("add user success!");}}

public class UserService {private UserDao dao &＃61; null;/* 提供UserDao的构造方法 或 set方法进行属性的赋值 */public UserService(UserDao dao) {this.dao &＃61; dao;}public void setDao(UserDao dao) {this.dao &＃61; dao;}/* 新增操作 */public void addUser() {this.dao.addUser();}}

使用Spring开发
在UserService中的属性dao就是一个对象类型.这里就需要用到注入对象类型的属性.要用到属性ref.ref 属性可以引用另一个 bean 的 id 或 name.

<bean id&＃61;"userService" class&＃61;"cn.com.yves.spring.UserService"><property name&＃61;"dao" ref&＃61;"userDao">property>bean>

name属性值dao为类UserService中的属性,ref的值:的id值.

具体代码如下:

package cn.com.yves.spring;public class UserDao {public void addUser() {System.out.println("add user success!");}
}

package cn.com.yves.spring;public class UserService {private UserDao dao &＃61; null;public void setDao(UserDao dao) {this.dao &＃61; dao;}public void addUser() {System.out.println("do add user service.");this.dao.addUser();}}


<beans xmlns&＃61;"http://www.springframework.org/schema/beans" xmlns:xsi&＃61;"http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation&＃61;"http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"><bean id&＃61;"userService" class&＃61;"cn.com.yves.spring.UserService"><property name&＃61;"dao" ref&＃61;"userDao">property>bean><bean id&＃61;"userDao" class&＃61;"cn.com.yves.spring.UserDao">bean>beans>

测试方法:

&＃64;Testpublic void test() {// 1 加载spring配置文件&＃xff0c;根据配置创建对象ApplicationContext context &＃61; new ClassPathXmlApplicationContext("Application.xml");// 2 配置文件中的id获取创建的对象UserService service &＃61; (UserService) context.getBean("userService");service.addUser();}

结果:

do add user service.
add user success!

spring-属性注入(对象类型)

属性注入-注入复杂类型属性

这里以简单的String类型为例子,如果子类型时对象类型,可以参考注入对象的ref属性来注入.

User.java

package cn.com.yves.spring;import java.util.List;
import java.util.Map;
import java.util.Properties;public class User {private String[] arrays;private List lists;private Map maps;private Properties props; // 最终实现的mappublic String[] getArrays() {return arrays;}public void setArrays(String[] arrays) {this.arrays &＃61; arrays;}public List getLists() {return lists;}public void setLists(List lists) {this.lists &＃61; lists;}public Map getMaps() {return maps;}public void setMaps(Map maps) {this.maps &＃61; maps;}public Properties getProps() {return props;}public void setProps(Properties props) {this.props &＃61; props;}public void showInfo() {System.out.println("message:" &＃43; this.arrays &＃43; "\t" &＃43; this.lists &＃43; "\t" &＃43; this.maps &＃43; "\t" &＃43; this.props);}}

Application.xml


<beans xmlns&＃61;"http://www.springframework.org/schema/beans" xmlns:xsi&＃61;"http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation&＃61;"http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"><bean id&＃61;"user" class&＃61;"cn.com.yves.spring.User"><property name&＃61;"arrays"><list><value>array1value><value>array2value><value>array3value>list>property><property name&＃61;"lists"><list><value>list1value><value>list2value><value>list3value>list>property><property name&＃61;"maps"><map><entry key&＃61;"aa" value&＃61;"lucy">entry><entry key&＃61;"bb" value&＃61;"jack">entry><entry key&＃61;"cc" value&＃61;"yves">entry>map>property><property name&＃61;"props"><props><prop key&＃61;"driverclass">com.mysql.jdbc.Driverprop><prop key&＃61;"username">rootprop>props>property>bean>beans>

测试代码:

&＃64;Testpublic void test() {// 1 加载spring配置文件&＃xff0c;根据配置创建对象ApplicationContext context &＃61; new ClassPathXmlApplicationContext("Application.xml");// 2 配置文件中的id获取创建的对象User user &＃61; (User) context.getBean("user");user.showInfo();}

结果:

message:[Ljava.lang.String;&＃64;77ec78b9 [list1, list2, list3] {aa&＃61;lucy, bb&＃61;jack, cc&＃61;yves} {driverclass&＃61;com.mysql.jdbc.Driver, username&＃61;root}

spring-属性注入(复杂类型)