Question

我正在尝试学习spring和bean配置。

我将会有几个类与DB相关的函数，所以每个类都需要有一个JdbcTemplate类。因为我想创建一个bean配置，它将为我的每个DB相关类注入一个单独的JdbcTemplate类。

我创建了以下bean配置。

<bean id="dataSource" class="org.apache.tomcat.jdbc.pool.DataSource">  
    <property name="driverClassName" value="com.mysql.jdbc.Driver" />  
    <property name="url" value="jdbc:mysql://localhost:3306/foo"/>  
    <property name="username" value="root"></property>  
    <property name="password" value="password"></property>  
        <property name="validationQuery" value="SELECT 1" />
    <property name="testOnBorrow" value="true" />
    <property name="testWhileIdle" value="true" />
     <property name="initialSize" value="5" />  
</bean>   

<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate" scope="singleton">
 <constructor-arg ref="dataSource"></constructor-arg> 
</bean>

当我将constructor-args参数添加到jdbcTemplate时，问题就开始了。 jdbctemplate需要将数据源作为参数接收到它的构造函数。但是当我添加该属性并尝试执行我的应用程序时，这是我得到的例外：

java.lang.IncompatibleClassChangeError: class org.springframework.core.LocalVariableTableParameterNameDiscoverer$ParameterNameDiscoveringVisitor has interface org.springframework.asm.ClassVisitor as super class
java.lang.ClassLoader.defineClass1(Native Method)
java.lang.ClassLoader.defineClass(ClassLoader.java:791)
java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
org.apache.catalina.loader.WebappClassLoader.findClassInternal(Unknown Source)
org.apache.catalina.loader.WebappClassLoader.findClass(Unknown Source)
org.apache.catalina.loader.WebappClassLoader.loadClass(Unknown Source)
org.apache.catalina.loader.WebappClassLoader.loadClass(Unknown Source)
org.springframework.core.LocalVariableTableParameterNameDiscoverer.inspectClass(LocalVariableTableParameterNameDiscoverer.java:112)
org.springframework.core.LocalVariableTableParameterNameDiscoverer.getParameterNames(LocalVariableTableParameterNameDiscoverer.java:85)
org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:193)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1045)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:949)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:487)
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:458)
org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:626)
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139)
org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83)

我错过了什么？

谢谢你！

Answer 1

如果你想要jdbcTemplate

，请尝试编码

 <!-- DataSource configuration for Apache Commons DBCP. -->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"
          p:driverClassName="${jdbc.driver}" p:url="${jdbc.url}"
          p:username="${jdbc.username}" p:password="${jdbc.password}"/>

 <!--jdcb template for DB tests-->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.simple.SimpleJdbcTemplate">
        <constructor-arg type="javax.sql.DataSource" ref="dataSource"/>
    </bean>

Answer 2

错误是有一个jdbcTemplate tyring来引用一个名为“dataSource2”的dataSource ...但你已经定义了一个名为“dataSource”的文件

检查应用程序中的所有spring上下文文件，看看如下所示的jdbc模板：

<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate" scope="singleton">
 <constructor-arg ref="dataSource2"></constructor-arg> 
</bean>

也许你已经意外地宣布了两个。如果没有尝试刷新项目，清理等。

Answer 3

试试这个 Bean.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">

    <bean id="customerDAO" class="com.shreyansh.dao.impl.JdbcCustomerDAO">
        <property name="dataSource" ref="dataSource" />
    </bean>

</beans>

弹簧Datasource.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">

    <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/shreyansh" />
        <property name="username" value="root" />
        <property name="password" value="password" />
    </bean>

</beans>

弹簧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="customer/Spring-Customer.xml" />

</beans>

Answer 4

看到你的错误 java.lang.IncompatibleClassChangeError 。这是抛出的当某个类发生不兼容的类更改时所以，它似乎是版本问题。你能告诉你使用的是java，spring和system的哪个版本。

将数据源添加到Jdbctemplate bean会引发异常

4 个答案: