Question

问题非常奇怪。我的IDE是IDEA。 Spring版本是4.3.1.RELEASE.Blow是我的项目结构

Blow是web.xml（简单）

<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.4"
         xmlns="http://java.sun.com/xml/ns/j2ee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
    http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

    <display-name>Spring MVC Application</display-name>
    <servlet>
        <servlet-name>SpringMVC</servlet-name>
        <servlet-class>
            org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/applicationContext.xml,
            /WEB-INF/infrastructure.xml
        </param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

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

    <servlet-mapping>
        <servlet-name>SpringMVC</servlet-name>
        <url-pattern>/home/profile</url-pattern>
    </servlet-mapping>

    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.html</url-pattern>
    </servlet-mapping>
</web-app>

apllicationContext.xml只有一行

<context:component-scan base-package="net.codespace.entity, net.codespace.DAO, net.codespace.service" />

Blow是SpringMVC-servlet.xml

<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:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd">

    <context:component-scan base-package="net.codespace" />
    <mvc:annotation-driven />
    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/home/" />
        <property name="suffix" value=""/>
    </bean>
</beans>

PersonDAO是界面。代码是Blow

import net.codespace.entity.Person;

public interface PersonDAO {
    public void save(Person p);
    public void findAll();
}

PersonDAOImpl是实现。

import net.codespace.entity.Person;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

@Repository("personDAO")
public class PersonDAOImpl implements PersonDAO{
    @Autowired
    private SessionFactory sessionFactory;
    public void save(Person p){

    }
    public void findAll(){

    }
}

同样，PersonService是接口，

package net.codespace.service;

/**
 * Created by mark on 2016/7/26.
 */
import net.codespace.entity.Person;

public interface PersonService {
    public void savePerson(Person p);
    public void getAllPerson(Person p);
}

PersonServiceImpl正在打击

import net.codespace.entity.Person;
import net.codespace.DAO.PersonDAO;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service("personService")
@Transactional
public class  PersonServiceImpl implements PersonService{
    @Autowired
    private PersonDAO personDAO;

    public void savePerson(Person p){

    }
    public void getAllPerson(Person p){
        System.out.println("punk your pieese");
    }
}

pom

<?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>net.markliang</groupId>
    <artifactId>lsc-toy</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
            <jackson.version>2.6.3</jackson.version>
            <hibernate.version>4.3.5.Final</hibernate.version>
            <spring.version>4.3.1.RELEASE</spring.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-web</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-orm</artifactId>
            <version>${spring.version}</version>
        </dependency>

        <dependency>
            <groupId>tomcat</groupId>
            <artifactId>servlet-api</artifactId>
            <version>5.5.23</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>${jackson.version}</version>
        </dependency>

        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>

        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.6.3</version>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.1.0.Final</version>
        </dependency>

        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
            <version>5.1.3.Final</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.31</version>
        </dependency>
    </dependencies>

</project>

当我部署此项目时，我收到了这些错误（显示重要）

严重: 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 'personService' defined in file 
[C:\Users\mark\IdeaProjects\SMS01\out\artifacts\SMS01_war_exploded\WEB-INF\classes\net\codespace\service\PersonServiceImpl.class]: Post-processing failed of bean type [class net.codespace.service.PersonServiceImpl] failed; nested exception is java.lang.IllegalStateException: Failed to introspect bean class [net.codespace.service.PersonServiceImpl] for persistence metadata: could not find class that it depends on
Caused by: java.lang.IllegalStateException: Failed to introspect bean class [net.codespace.service.PersonServiceImpl] for 
persistence metadata: could not find class that it depends on
/* some info */

Caused by: java.lang.NoClassDefFoundError: Lnet/codespace/DAO/PersonDAO;
/* some info */

Caused by: java.lang.ClassNotFoundException: net.codespace.DAO.PersonDAO
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1891)
    at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1734)
  /*some info */

有人可以帮助我吗？如果您需要更多详细信息，我可以发送邮件。谢谢

Answer 1

您需要了解applicationContext和servlet-context之间的区别（请查看此answer。

您的servlet上下文不应该扫描持久层，因为持久层应该具有应用程序范围，这意味着可用于所有servlet。

在SpringMvc中，仅扫描控制器：

<context:component-scan base-package="net.codespace.contrller" />

在您的应用程序上下文中，您应该扫描存储库和服务，以便可以对它们进行bean连接。

Answer 2

java.lang.ClassNotFoundException: net.codespace.DAO.PersonDAO和java.lang.NoClassDefFoundError: Lnet/codespace/DAO/PersonDAO应该是主要问题。

您需要检查为什么PersonDAO在类路径上不可用。请尝试以下方法：

PersonDAO.java文件中的包声明是否与文件夹结构匹配？（它在您的帖子中被省略或在文件中丢失），即package net.codespace.DAO;
运行mvn clean install并（确保编译并完成正常）检查target/classes/net/codespace/DAO/PersonDAO.class是否存在。
如果以上情况正常，那么您需要检查类路径以查看无法找到此类的原因 - 这取决于您运行应用程序的方式（在IDE或Maven等中）。

注意这不是问题，但Java naming convention for packages是小写的，所以理想情况下你的包名应该是net.codespace.dao

SpringMVC BeanCreationException：创建文件PersonServiceImpl.class中定义的名为'personService'的bean？

2 个答案: