【发布时间】：2015-09-14 12:03:00
【问题描述】：
这是我的组件，其中包含 userService 自动连线。问题是未初始化，始终为空。用户服务在控制器中运行良好。
如何在组件内部自动装配服务？
package com.boro.orange.component;
@Component("modelUtil")
public class ModelUtil {
@Autowired
private UserService userService; //null
static Logger log = Logger.getLogger(ModelUtil.class.getName());
public ModelMap warp(ModelMap model) {
Object springUserObject = SecurityContextHolder.getContext().getAuthentication().getPrincipal();
if (springUserObject == null || !(springUserObject instanceof User)) {
return model;
}
User springUser = (User) springUserObject;
String userEmailAddress = springUser.getUsername();
com.boro.orange.entity.User signedInUser = userService.getUserByEmailAddress(userEmailAddress);
if (signedInUser == null) {
String errorMsg = "Failed to find user by email address[" + userEmailAddress + "]";
log.error(errorMsg);
model.addAttribute("Error", errorMsg);
// TODO add error messages
} else {
String userFirstName = signedInUser.getFirstName();
String userLastName = signedInUser.getLastName();
model.addAttribute("userFirstName", userFirstName);
model.addAttribute("userLastName", userLastName);
}
return model;
}
}
root-context.xml:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd">
<context:annotation-config/>
<context:component-scan base-package="com.boro.orange.dao"/>
<context:component-scan base-package="com.boro.orange.service"/>
<context:component-scan base-package="com.boro.orange.component"/>
<context:component-scan base-package="com.boro.orange.controller"/>
<import resource="data.xml"/>
</beans>
【问题讨论】：
-
UserService上有Service注解吗？可以加个限定符注解吗？
-
@duffymo，是的，UserService 可以在其他 @Controller 类中正常工作。
-
无法从这段代码中看出你做错了什么。
-
你如何使用
ModelUtil这个类？如果您使用new ModelUtil()自己实例化它，那么它不是 Spring 托管 bean，并且不会完成自动装配。见：Spring Dependency Injection Autowiring Null -
显示你调用
warp的班级。