Question

我想使用spring和hibernate做小应用程序，我遇到了上述问题，我已经查看了与上述问题相关的答案，但我无法使用这些答案解决它。

包结构

com.library.bean
com.library.controller
com.library.dao
com.library.service

每个包下的文件都是

在 com.library.bean - LoginBean.java
中
在 com.library.controller 中 - LoginController.java

在 com.library.dao - DataAccessObject.java

在 com.library.service - UserCreditentialsService.java

很抱歉发布长代码

LoginController.java

package com.library.controller;

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

import com.library.bean.LoginBean;
import com.library.service.UserCreditentialsService;

@Controller
public class LoginController {

    @Autowired
    private UserCreditentialsService service;

    public void setService(UserCreditentialsService service) {
        this.service = service;
    }

    @RequestMapping(value="/",method=RequestMethod.GET)
    public void renderPageService(){
        String username="james";
        String password="johnson";
        LoginBean bean = new LoginBean();
        bean.setUsername(username);
        bean.setPassword(password);
        this.service.checkValidUser(bean);  
    }

}

DataAccessObject.java

package com.library.dao;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;

import com.library.bean.LoginBean;

@Repository
public class DataAccessObject {

    @Autowired
    private SessionFactory sessionFactory;

    public void setSessionFactory(SessionFactory sessionFactory) {
        this.sessionFactory = sessionFactory;
    }

    public boolean isValidUser(LoginBean bean){
        Session session = this.sessionFactory.getCurrentSession();
        session.save(bean);
        return true;
    }


}

UserCreditentialsService.java

package com.library.service;

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

import com.library.bean.LoginBean;
import com.library.dao.DataAccessObject;

@Service
public class UserCreditentialsService {

    @Autowired
    private DataAccessObject dao;

    public void setDao(DataAccessObject dao) {
        this.dao = dao;
    }

    @Transactional
    public boolean checkValidUser(LoginBean bean){
        return this.dao.isValidUser(bean);
    }

}

LoginBean.java

        package com.library.bean;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

import org.springframework.stereotype.Component;

@Component
@Entity
@Table(name="Login")
public class LoginBean {

    @Id
    @Column(name="username")
    private String username;

    @Column(name="password")
    private String password;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

弹簧servlet.xml中

<?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:tx="http://www.springframework.org/schema/tx"
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
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">

<annotation-driven />


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

<!-- 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/jsp/" />
    <beans:property name="suffix" value=".jsp" />
</beans:bean>

<beans:bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
    destroy-method="close">
    <beans:property name="driverClassName" value="oracle.jdbc.driver.OracleDriver" />
    <beans:property name="url"
        value="jdbc:oracle:thin:@localhost:1521:xe" />
    <beans:property name="username" value="hr" />
    <beans:property name="password" value="hr" />
</beans:bean>

<!-- Hibernate 4 SessionFactory Bean definition -->
<beans:bean id="hibernate4AnnotatedSessionFactory"
    class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
    <beans:property name="dataSource" ref="dataSource" />
    <beans:property name="annotatedClasses">
        <beans:list>
            <beans:value>com.library.bean.LoginBean</beans:value>
        </beans:list>
    </beans:property>
    <beans:property name="hibernateProperties">
        <beans:props>
            <beans:prop key="hibernate.dialect">org.hibernate.dialect.OracleDialect</beans:prop>
            <beans:prop key="hibernate.show_sql">true</beans:prop>
            <beans:prop key="hibernate.hbm2ddl.auto">update</beans:prop>
        </beans:props>
    </beans:property>
</beans:bean>

<beans:bean id="logindao" class="com.library.dao.DataAccessObject">
    <beans:property name="sessionFactory" ref="hibernate4AnnotatedSessionFactory" />
</beans:bean>



<beans:bean id="service" class="com.library.service.UserCreditentialsService">
    <beans:property name="dao" ref="logindao"/>
</beans:bean>

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

<tx:annotation-driven transaction-manager="transactionManager"/>

<beans:bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager">
    <beans:property name="sessionFactory" ref="hibernate4AnnotatedSessionFactory" />
</beans:bean>

的web.xml

<display-name>Library</display-name>
    <servlet>
    <servlet-name>spring</servlet-name>
    <servlet-class>
        org.springframework.web.servlet.DispatcherServlet
    </servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>spring</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

我得到的错误是


org.springframework.beans.factory.BeanCreationException：创建名为'service'的bean时出错：注入自动连接的依赖项失败;嵌套异常是org.springframework.beans.factory.BeanCreationException：无法自动装配字段：private com.library.dao.DataAccessObject com.library.service.UserCreditentialsService.dao;嵌套异常是org.springframework.beans.factory.NoSuchBeanDefinitionException：没有定义[com.library.dao.DataAccessObject]类型的唯一bean：期望的单个匹配bean但找到2：[logindao，dataAccessObject]

Answer 1

问题是您有2个DataAccessObject类型的bean：logindao和dataAccessDao。

因此，Spring无法决定您希望在UserCredentialsService中使用哪一个并拒绝启动。

打破这两个bean的层次结构，这个错误消失了。

当我运行tomcat时，我得到NoSuchBeanCreation错误

1 个答案: