java 我无法在春季自动装配存储库

I can't autowire repository in spring

提问by Black

I am trying to autowire repository in controller using spring annotation. I am getting error org.springframework.data.repository.query.QueryByExampleExecutor class not foundfor which I couldn't find a solution.

我正在尝试使用 spring 注释在控制器中自动装配存储库。我收到错误org.springframework.data.repository.query.QueryByExampleExecutor class not found，找不到解决方案。

Error that I am getting:

我得到的错误：

SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'articleController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.payforeign.article.ArticleRepository com.payforeign.article.ArticleController.repository; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'articleRepository': Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: org/springframework/data/repository/query/QueryByExampleExecutor

Controller

控制器

package com.payforeign.article;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
@RequestMapping("/service")
public class ArticleController {

   @Autowired
   private ArticleRepository repository;

   //controller methods
}

Repository

存储库

I have annotated repository with @Repository. According to spring documentation I am having only repository interface. Is it correct?

我用@Repository. 根据 spring 文档，我只有存储库接口。这是正确的吗？

package com.payforeign.article;

import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface ArticleRepository extends CrudRepository<Article, Long> {}

applicationContext.xml

应用上下文.xml

I have included jpa:repositorieswith correct base-packageand component-scan. I have specified that it is annotation driven (<mvc:annotation-driven /> <tx:annotation-driven />) and added JDBC and JPA settings. My applicationContext.xml is correctly loaded from web.xml

我已经包含jpa:repositories了正确的base-package和component-scan。我已经指定它是注释驱动的 ( <mvc:annotation-driven /> <tx:annotation-driven />) 并添加了 JDBC 和 JPA 设置。我的 applicationContext.xml 从 web.xml 正确加载

<?xml version='1.0' encoding='UTF-8' ?>
<beans ...>
    <context:component-scan base-package="com.payforeign,com.payforeign.article" />
    <mvc:annotation-driven />
    <jpa:repositories base-package="com.payforeign.article" />

    <!-- Data Source -->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close" >
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost/payforeign" />
        <property name="username" value="root" />
        <property name="password" value="" />
    </bean>

    <!-- Hibernate -->
    <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="packagesToScan" value="com.payforeign.article" />
        <property name="jpaVendorAdapter">
            <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
                <property name="showSql" value="true" />
                <property name="generateDdl" value="true" />
                <property name="database" value="MYSQL" />
            </bean>
        </property>
    </bean>

    <!-- enable the configuration of transactional behavior based on annotations -->
    <tx:annotation-driven />
    <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
        <property name="entityManagerFactory" ref="entityManagerFactory" />
    </bean>
</beans>

回答by Viacheslav Shalamov

Your issue is about dependencies.

您的问题与依赖项有关。

The class, you are looking for is here: https://github.com/spring-projects/spring-data-jpa/blob/master/src/main/java/org/springframework/data/jpa/repository/JpaRepository.java

您正在寻找的课程在这里：https: //github.com/spring-projects/spring-data-jpa/blob/master/src/main/java/org/springframework/data/jpa/repository/JpaRepository。爪哇

As you can see, the latest version of spring-data-jpa has it, therefore you should either upgrade your failing delendency to the latest version or downdrade spring-data-jpa version a little bit (not recommended).

如您所见，最新版本的 spring-data-jpa 具有它，因此您应该将失败的依赖升级到最新版本，或者稍微降级 spring-data-jpa 版本（不推荐）。

I had similar problem in my application with spring boot and mongoDB jpa repositories.

我的应用程序在使用 spring boot 和 mongoDB jpa 存储库时遇到了类似的问题。

As example, I have spring-data-jpa and spring-data-mongodb dependencies:

例如，我有 spring-data-jpa 和 spring-data-mongodb 依赖项：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency> 
<dependency>
    <groupId>org.springframework.data</groupId>
    <artifactId>spring-data-mongodb</artifactId>
    <version>1.9.2.RELEASE</version>
</dependency>

But spring boot spring-boot-starter-data-jpa implicitly uses an older version of spring-data-mongodb than 1.9.2.RELEASE. The easiest way to fix was to downgrade spring-data-mongodb to 1.8.4.RELEASE version.

但是 spring boot spring-boot-starter-data-jpa 隐式使用了比 1.9.2.RELEASE 更旧的 spring-data-mongodb 版本。最简单的修复方法是将 spring-data-mongodb 降级到 1.8.4.RELEASE 版本。

回答by tcharaf

Try to add this config in your applicationContext.xml

尝试在 applicationContext.xml 中添加此配置

<context:annotation-config/>

回答by naXa

You may encounter NoClassDefFoundErrorif the version of spring-data-commonsis older then required by spring-data-jpa. This exception nearly always means a version mismatch (dependency hell). Here's an example of such a bad dependency combination:

您可能会遇到NoClassDefFoundError，如果版本spring-data-commons是旧的然后要求spring-data-jpa。这个异常几乎总是意味着版本不匹配（依赖地狱）。这是这种不良依赖组合的示例：

<dependency>
    <groupId>org.springframework.data</groupId>
    <artifactId>spring-data-commons</artifactId>
    <version>1.6.2.RELEASE</version>
</dependency>

<dependency>
    <groupId>org.springframework.data</groupId>
    <artifactId>spring-data-jpa</artifactId>
    <version>1.11.8.RELEASE</version>
</dependency>

The solution is as simple as removing spring-data-commonsfrom your project dependencies (anyway you don't need to explicitly specify this library cause it's a transitive dependency of spring-data-jpa).

解决方案就像spring-data-commons从项目依赖项中删除一样简单（无论如何，您不需要显式指定此库，因为它是 的传递依赖项spring-data-jpa）。

回答by Charnjeet Singh

Please change the

请更改

<context:component-scan base-package="com.payforeign,com.payforeign.article" />

to

到

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

It is define the base package using this you com.payforeign.articlewill automatically scan.

它是使用此定义基本包，您com.payforeign.article将自动扫描。