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我有处理用户实体的用户服务，并在使用用户服务之前在用户控制器类中使用 @Autowired。所以，我得到了错误：

Unsatisfied 'required' dependency of type [class com.yes.service.UserService]. Expected at least 1 matching bean

这里的代码：

用户服务

package com.yes.service;

import java.util.List;
import java.util.UUID;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.yes.domain.User;
import com.yes.repository.RoleRepository;
import com.yes.repository.UserRepository;

@Service
public class UserService {


    @Autowired
    private UserRepository userRepository;
    @Autowired
    private RoleRepository roleRepository;

    public User create(User user) {
        user.setId(UUID.randomUUID().toString());
        user.getRole().setId(UUID.randomUUID().toString());
        // We must save both separately since there is no cascading feature
        // in Spring Data MongoDB (for now)
        roleRepository.save(user.getRole());
        return userRepository.save(user);
    }
    public User read(User user) {
        return user;
    }
    public List<User> readAll() {
        return userRepository.findAll();
    }
    public User update(User user) {
        User existingUser = userRepository.findByUsername(user.getUserName());
        if (existingUser == null) {
            return null;
        }
        existingUser.setFirstName(user.getFirstName());
        existingUser.setLastName(user.getLastName());
        existingUser.getRole().setRole(user.getRole().getRole());
        // We must save both separately since there is no cascading feature
        // in Spring Data MongoDB (for now)
        roleRepository.save(existingUser.getRole());
        return userRepository.save(existingUser);
    }
    public Boolean delete(User user) {
        User existingUser = userRepository.findByUsername(user.getUserName());
        if (existingUser == null) {
            return false;
        }
        // We must delete both separately since there is no cascading feature
        // in Spring Data MongoDB (for now)
        roleRepository.delete(existingUser.getRole());
        userRepository.delete(existingUser);
        return true;
    }
}

userController（我在哪里使用 userService，问题是）

@Controller
@RequestMapping("/users")
public class UserController {

    @Autowired
    private UserService service;
    @RequestMapping
    public String getUsersPage() {
        return "users";
    }
    @RequestMapping(value="/records")
    public @ResponseBody UserListDto getUsers() {
        UserListDto userListDto = new UserListDto();
        userListDto.setUsers(service.readAll());
        return userListDto;
    }
    @RequestMapping(value="/get")
    public @ResponseBody User get(@RequestBody User user) {
        return service.read(user);
    }

    @RequestMapping(value="/create", method=RequestMethod.POST)
    public @ResponseBody User create(
            @RequestParam String username,
            @RequestParam String password,
            @RequestParam String firstName,
            @RequestParam String lastName,
            @RequestParam Integer role) {

        Role newRole = new Role();
        newRole.setRole(role);
        User newUser = new User();
        newUser.setUserName(username);
        newUser.setPassword(password);
        newUser.setFirstName(firstName);
        newUser.setLastName(lastName);
        newUser.setRole(newRole);
        return service.create(newUser);
    }
    @RequestMapping(value="/update", method=RequestMethod.POST)
    public @ResponseBody User update(
            @RequestParam String username,
            @RequestParam String firstName,
            @RequestParam String lastName,
            @RequestParam Integer role) {

        Role existingRole = new Role();
        existingRole.setRole(role);
        User existingUser = new User();
        existingUser.setUserName(username);
        existingUser.setFirstName(firstName);
        existingUser.setLastName(lastName);
        existingUser.setRole(existingRole);
        return service.update(existingUser);
    }
    @RequestMapping(value="/delete", method=RequestMethod.POST)
    public @ResponseBody Boolean delete(
            @RequestParam String username) {

        User existingUser = new User();
        existingUser.setUserName(username);
        return service.delete(existingUser);
    }
}

弹簧数据.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:p="http://www.springframework.org/schema/p"
    xmlns:c="http://www.springframework.org/schema/c" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:mongo="http://www.springframework.org/schema/data/mongo"
    xmlns:util="http://www.springframework.org/schema/util"
    xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/data/mongo
http://www.springframework.org/schema/data/mongo/spring-mongo-1.0.xsd
http://www.springframework.org/schema/util
http://www.springframework.org/schema/util/spring-util-3.1.xsd">

    <context:property-placeholder
        properties-ref="deployProperties" />


    <!-- MongoDB host -->
    <mongo:mongo host="${mongo.host.name}" port="${mongo.host.port}" />

    <!-- Template for performing MongoDB operations -->
    <bean id="mongoTemplate" class="org.springframework.data.mongodb.core.MongoTemplate"
        c:mongo-ref="mongo" c:databaseName="${mongo.db.name}" />

    <!-- Activate Spring Data MongoDB repository support -->
    <mongo:repositories base-package="com.yes.repository" mongo-template-ref="mongoTemplate"/>



    <!-- Service for initializing MongoDB with sample data using MongoTemplate -->
    <bean id="initMongoService" class="com.yes.service.InitMongoService" init-method="init"/>
</beans>

servlet-context.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:beans="http://www.springframework.org/schema/beans"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.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.xsd">

<!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->

<!-- Enables the Spring MVC @Controller programming model -->
<annotation-driven />
<context:component-scan base-package="com.yes.controller"/>



<!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
<resources mapping="/resources/**" location="/resources/" />

<!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->
<beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <beans:property name="prefix" value="WEB-INF/views/" />
    <beans:property name="suffix" value=".jsp" />
</beans:bean>

应用程序上下文.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"
xmlns:p="http://www.springframework.org/schema/p" xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<context:property-placeholder
    properties-ref="deployProperties" />

<!-- Activates various annotations to be detected in bean classes -->
<context:annotation-config />

<!-- Scans the classpath for annotated components that will be auto-registered 
    as Spring beans. For example @Controller and @Service. Make sure to set the 
    correct base-package -->

    <context:component-scan base-package="com.yes.domain"/>
    <context:component-scan base-package="com.yes.dto"/>
    <context:component-scan base-package="com.yes.service"/>

<!-- Configures the annotation-driven Spring MVC Controller programming 
    model. Note that, with Spring 3.0, this tag works in Servlet MVC only! -->
<mvc:annotation-driven />
<mvc:resources mapping="/resources/**" location="/resources/" />

<!-- Imports datasource configuration -->
<import resource="spring-data.xml" />
<bean id="deployProperties"
    class="org.springframework.beans.factory.config.PropertiesFactoryBean"
    p:location="/WEB-INF/spring/spring.properties" />

错误堆栈：

ERROR: org.springframework.web.servlet.DispatcherServlet - Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.yes.service.UserService com.yes.controller.UserController.service; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No matching bean of type [com.yes.service.UserService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:287)

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">

    <!-- The definition of the Root Spring Container shared by all Servlets and Filters -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/spring/applicationContext.xml</param-value>
    </context-param>

    <!-- Creates the Spring Container shared by all Servlets and Filters -->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <!-- Processes application requests -->
    <servlet>
        <servlet-name>appServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>/WEB-INF/spring/appServlet/servlet-context.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>appServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

编辑：问题是在修复 Sotirios Delimanolis 回答和评论中写的错误之后。

是什么问题导致错误？

回答：问题出在 Sotirios Delimanolis 的回答中。对他的回答的评论中描述的确切解决方案

谢谢你

4

1 回答 1

2

您的应用程序上下文和 servlet 上下文是对相同包的组件扫描。

您的应用程序上下文

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

与 servlet 上下文中的所有内容相比

<context:component-scan base-package="com.yes.service"/>
<context:component-scan base-package="com.yes.controller"/>
<context:component-scan base-package="com.yes.domain"/>
<context:component-scan base-package="com.yes.repository"/>
<context:component-scan base-package="com.yes.dto"/>

所以一些bean将被覆盖。你不想要这个。您的 servlet 上下文应该扫描@Controllerbean。您的应用程序上下文应该扫描其他所有内容，但不要让您的应用程序上下文扫描您的子（导入）数据上下文已经扫描的内容。修复你的包声明，使所有这些都是不相交的。

于 2013-08-27T19:04:02.523 回答