org.springframework.beans.factory.BeanCreationException：以及 org.springframework.beans.BeanInstantiationException

Question

我尝试在 spring 中进行登录和一些数据库操作（插入、删除）并帮助 jsp。我对 spring 完全陌生。我收到以下错误，如 bean 创建异常。我已将 dvd 定义为 servlet 名称在 web.xml 中。所以我的 dvd_servlet.xml 文件如下所示

<beans.................>
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
    <property name="prefix" value="/"/>
    <property name="suffix" value=".jsp"/>
</bean>

<bean id="dataSource" destroy-method="close" class="org.apache.commons.dbcp.BasicDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/DVD"/>
        <property name="username" value="root"/>
        <property name="password" value="root"/>
</bean>

<bean name="DvdController" class="DvdController" >
    <property name="dataSource" ref="dataSource"/>
</bean>
<bean name="LoginController" class="LoginController" >
    <property name="dataSource" ref="dataSource"/>
</bean>
<bean name="AccountCreationController" class="AccountCreationController" >
    <property name="dataSource" ref="dataSource"/>
</bean>
</beans>

我的 LoginController 是这样的

public class LoginController implements Controller   {

     int check;
    private DataSource dataSource;
     public void setDataSource(DataSource dataSource) {
    this.dataSource=dataSource;
    }
    public DataSource getDataSource() {
    return dataSource;
    }

    JdbcTemplate jdbcTemplate=new JdbcTemplate(dataSource);
    @RequestMapping(value="/Login",method=RequestMethod.POST)
    public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) {                       
                String userName = request.getParameter("userName");
            String password=request.getParameter("password");
            try {
            String selectQuery=("SELECT * FROM USERDETAILS WHERE NAME='"+userName+"'AND PASSWORD='"+password+"'");
                check=jdbcTemplate.update(selectQuery,new Object[]{});  
                System.out.println(check);
                if(check!=0) {
                response.sendRedirect("DvdController");

                }
            }

            catch(IOException e) {
            e.printStackTrace();            
            }

            return new ModelAndView("failure"); 
    }

我的错误如下：

org.springframework.beans.factory.BeanCreationException：创建 ServletContext 资源 [/WEB-INF/dvd-servlet.xml] 中定义的名称为“LoginController”的 bean 时出错：bean 的实例化失败；嵌套异常是 org.springframework.beans.BeanInstantiationException：无法实例化 bean 类 [LoginController]：构造函数抛出异常；嵌套异常是 java.lang.IllegalArgumentException: Property 'dataSource' is required org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(support:AbstractAutowireCapableBeanFactory.java):965) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(support:AbstractAutowireCapableBeanFactory.java):911) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(support:AbstractAutowireCapableBeanFactory.java):485) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(support:AbstractAutowireCapableBeanFactory.java):456) org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(support:AbstractBeanFactory.java):291) org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(support:DefaultSingletonBeanRegistry.java):222) org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(support:AbstractBeanFactory.java):288) org.springframework.beans.factory.support.AbstractBeanFactory.getBean(support:AbstractBeanFactory.java):190) org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(support:DefaultListableBeanFactory.java):580) org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895) org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:442) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:458)

根本原因

org.springframework.beans.BeanInstantiationException：无法实例化bean类[LoginController]：构造函数抛出异常；嵌套异常是 java.lang.IllegalArgumentException: Property 'dataSource' is required org.springframework.beans.BeanUtils.instantiateClass(beans:BeanUtils.java):141) org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(support:SimpleInstantiationStrategy.java):74) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(support:AbstractAutowireCapableBeanFactory.java):958) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(support:AbstractAutowireCapableBeanFactory.java):911) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(support:AbstractAutowireCapableBeanFactory.java):485) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(support:AbstractAutowireCapableBeanFactory.java):456) org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(support:AbstractBeanFactory.java):291) org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(support:DefaultSingletonBeanRegistry.java):222) org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(support:AbstractBeanFactory.java):288) org.springframework.beans.factory.support.AbstractBeanFactory.getBean(support:AbstractBeanFactory.java):190) org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(support:DefaultListableBeanFactory.java):580) org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895) org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:442) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:458)

根本原因

java.lang.IllegalArgumentException：需要属性“dataSource” org.springframework.jdbc.support.JdbcAccessor.afterPropertiesSet(support:JdbcAccessor.java):134) org.springframework.jdbc.core.JdbcTemplate.(core:JdbcTemplate.java):164) LoginController.(LoginController.java:29) sun.reflect.NativeConstructorAccessorImpl.newInstance0（本机方法） sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) java.lang.reflect.Constructor.newInstance(Constructor.java:513) org.springframework.beans.BeanUtils.instantiateClass(beans:BeanUtils.java):126) org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(support:SimpleInstantiationStrategy.java):74) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(support:AbstractAutowireCapableBeanFactory.java):958) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(support:AbstractAutowireCapableBeanFactory.java):911) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(support:AbstractAutowireCapableBeanFactory.java):485) org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(support:AbstractAutowireCapableBeanFactory.java):456) org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(support:AbstractBeanFactory.java):291) org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(support:DefaultSingletonBeanRegistry.java):222) org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(support:AbstractBeanFactory.java):288) org.springframework.beans.factory.support.AbstractBeanFactory.getBean(support:AbstractBeanFactory.java):190) org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(support:DefaultListableBeanFactory.java):580) org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895) org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:442) org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:458) org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:339)

请帮我解决这个问题！！！

Answer 1

我在这里看到两个问题：

<bean name="LoginController" class="LoginController" >
    <property name="dataSource" ref="dataSource"/>
</bean>

LoginController 真的是完全限定的类名吗？它应该类似于 com.cy.LoginController

其次，Spring 声明 LoginController 的构造函数需要属性 dataSource。看起来 LoginController 需要数据源的构造函数注入，你正在做的是 setter 注入，所以试试这个：

代替<property name="dataSource" ref="dataSource/>，写： <constructor-arg ref="dataSource"/>