Spring @Autowired variable is null inside of @Component

Question

Here is my component that contains userService auto wired. The problem is that is not initialized, always null. User service works fine from Controllers.

What should be done to autowire service inside of component?

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>

Is there a Service annotation on UserService? Can you add a Qualifier annotation? — duffymo, Jun 27 '15 at 17:56
@duffymo, yes, UserService works fine from other @ Controller classes. — Steve, Jun 27 '15 at 18:03
How are you using the class `ModelUtil`? If you instantiate it yourself with `new ModelUtil()` then it's not a Spring managed bean and autowiring will not be done. See: [Spring Dependency Injection Autowiring Null](http://stackoverflow.com/questions/8091203/spring-dependency-injection-autowiring-null) — Jesper, Jun 27 '15 at 19:44
Ping me if this isn't the problem, because it looks like the classic. — chrylis -cautiouslyoptimistic-, Jun 27 '15 at 20:37

score 0 · Accepted Answer · answered Jun 27 '15 at 19:41

0

You should use only one definition for component scan. The last one overrides previous definitions.

<context:component-scan base-package="com.boro.orange"/>

answered Jun 27 '15 at 19:41

Roman C

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Spring @Autowired variable is null inside of @Component

1 Answers1