没有定义名为“PlaceDAO”的 bean

Posted 2023-04-18

【中文标题】没有定义名为“PlaceDAO”的 bean

【英文标题】：No bean named 'PlaceDAO' is defined

【发布时间】：2015-12-13 23:37:16

【问题描述】：

我正在创建一个简单的应用程序，它应该使用 spring MVC 从数据库中打印一条记录。我设法到达这里，但现在我得到一个例外，上面写着：

SEVERE: Servlet.service() for servlet [SpringDispatcher] in context with path [/springProject] threw exception [Request processing failed; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'PlaceDAO' is defined] with root cause
org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'PlaceDAO' is defined

这是我的代码

Spring-Module.xml：

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">


    <import resource="database/Spring-Datasource.xml" />
    <import resource="place/Spring-Place.xml" />

</beans>

Spring-Place.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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

    <bean id="placeDAO" class="springProject.springProject.model.JdbcPlaceDAO">
        <property name="dataSource" ref="dataSource" />
    </bean>

</beans>

Spring-Datasource.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"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">

    <bean id="dataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">

        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/webservisdb" />
        <property name="username" value="root" />
        <property name="password" value="" />
    </bean>

</beans>

pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>springProject</groupId>
    <artifactId>springProject</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>war</packaging>

    <name>springProject</name>
    <url>http://maven.apache.org</url>

    <properties>
        <java.version>1.6</java.version>
        <spring.version>3.1.0.RELEASE</spring.version>
        <cglib.version>2.2.2</cglib.version>
    </properties>

    <dependencies>
        <!-- Spring core & mvc -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>$spring.version</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>$spring.version</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>$spring.version</version>
            <type>jar</type>
            <scope>compile</scope>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>$spring.version</version>
            <type>jar</type>
            <scope>test</scope>
        </dependency>

        <!-- CGLib for @Configuration -->
        <dependency>
            <groupId>cglib</groupId>
            <artifactId>cglib-nodep</artifactId>
            <version>$cglib.version</version>
            <scope>runtime</scope>
        </dependency>


        <!-- Servlet Spec -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.4</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.1</version>
            <scope>provided</scope>
        </dependency>

        <!-- MySQL database driver -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.9</version>
        </dependency>
    </dependencies>

    <repositories>
        <repository>
            <id>springsource-milestones</id>
            <name>SpringSource Milestones Proxy</name>
            <url>https://oss.sonatype.org/content/repositories/springsource-milestones</url>
        </repository>
    </repositories>

    <build>
        <finalName>springProject</finalName>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>2.0.2</version>
                <configuration>
                    <source>$java.version</source>
                    <target>$java.version</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

以及发生异常的我的控制器：

@RequestMapping(value="/getPlace")
    public ModelAndView getPlace(HttpServletResponse response) throws IOException

        ApplicationContext context = new ClassPathXmlApplicationContext("Spring-Module.xml");

        placeDAO = (PlaceDAO) context.getBean("PlaceDAO");
        Place p1 = placeDAO.getPlace(1);

        ModelAndView model=new ModelAndView("places/getPlace");
        model.addObject("text", p1.name);

        return model ;
    

最后是文件层次结构：

【问题讨论】：

Check this out

附带问题：为什么要创建自己的 Spring ApplicationContext？您不应该配置 servlet 容器为您创建它吗？

我创建它只是为了检查我的数据库是否配置正确，在我看来这是最快的检查方式。我当然会删除它并以其他方式删除它。

【参考方案1】：

您的示例中有错字：

context.getBean("PlaceDAO")

应该是：

context.getBean("placeDAO")