Spring--JDBCTemplate使用的问题

使用JDBCTemplate

首先创建一个Dao接口和实现类，添加注解创建对象，然后创建一个数据库表和实体类

创建service层代码，并注入Dao接口的bean对象，调用接口方法

配置文件中【有错】

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="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">
​
    <context:component-scan base-package="xlw.com.jdbcTemplate"></context:component-scan>
    
    <context:property-override location="classpath:jdbc.properties"></context:property-override>
    
    <bean id="jdbc" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${druid.DriverClassname}"></property>
        <property name="url" value="${druid.url}"></property>
        <property name="username" value="${druid.username}"></property>
        <property name="password" value="${druid.password}"></property>
    </bean>
​
<!--创建JDBCTemplate bean对象-->
    <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
        <property name="dataSource" ref="jdbc"></property>
    </bean>
</beans>

 

 

Dao中

@Component
public interface UserDao {
    void add(User user);
}

 

 

DaoImpl中

@Repository
public class UserDaoImpl implements UserDao {
    @Autowired
    private JdbcTemplate jdbcTemplate;
​
    @Override
    public void add(User user) {
        String sql = "insert into o_User values (?,?,?)";
        int update = jdbcTemplate.update(sql, null, user.getUsername(), user.getPassword());
        System.out.println(update);
    }
}

 

 

Service中【没建立接口】

@Service
public class UserService {
    @Autowired
    private UserDao userDao;
​
    public void addUser(User user){
        userDao.add(user);
    }
}

 

随便建一个测试类

    ApplicationContext context = new ClassPathXmlApplicationContext("hao.xml");
@Test
public void testJDBCTemplate(){
    UserService userService = context.getBean("userService", UserService.class);
    User user = new User();
    user.setUsername("老王");
    user.setPassword("123abc");
    System.out.println(user.getPassword());
    userService.addUser(user);
}

 

问题出现了，本来输出一个影响行数但是报错了

Could not process key 'url' in PropertyOverrideConfigurer; nested exception is org.springframework.beans.factory.BeanInitializationException: Invalid key 'url': expected 'beanName.property'

 

这种的还有另一种说是jdbcTemplate建立的bean找不到，或者创建DaoImpl的bean出错，还有就是说表达式指向的内容找不到。其实这都是借口，问题是这个【DruidDataSource】类的bean对象的id他在上面叫jdbc，现在我改成了druid，然后在JDBCTemplate中注入这个bean就行，他就行了。神奇吧，神奇死了。

他半天一直在叫找不到jdbc这个bean在哪里，过一会又叫找不到druid这个bean在哪里。

<context:component-scan base-package="xlw.com.jdbcTemplate"></context:component-scan>
​
<context:property-override location="classpath:jdbc.properties"></context:property-override>
​
<bean id="druid" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close">
    <property name="url" value="${druid.url}"></property>
    <property name="username" value="${druid.username}"></property>
    <property name="password" value="${druid.password}"></property>
    <property name="driverClassName" value="${druid.driverClassName}"></property>
</bean>
<!--创建JDBCTemplate bean对象-->
<bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
    <property name="dataSource" ref="druid"></property>
</bean>

 

这时jdbc.properties文件【名字就叫这个】，mysql是8.0.21版本，可以自己去找对应的8.0.21的驱动jar包

druid.driverClassName=com.mysql.cj.jdbc.Driver
druid.url=jdbc:mysql://localhost:3308/o_user?characterEncoding=utf8&useSSL=true&serverTimezone=UTC
druid.username=root
druid.password=123456