在整合时controller调用service业务逻辑
service层调用dao层和数据库交互
解决思路:
1.bean有没有注入 √
2.junit单元测试,看service调用dao层能否查询成功 √
3.所以问题出在了spring上
…1):springMVC的配置文件,指向的是dispatcherServlet.xml,里面没有service的bean
视频所使用的解决方法:
1.将web.xml中springMVC配置所指向的文件改为applicationContext.xml
2.新建一个xml文件(称之为service层配置文件),里面的内容是原先applicationContext.xml的内容,自动扫描的包是service层,在applicationContext.xml里将两个或以上的配置import进来
3.DispatcherServlet.xml自动扫描的包是controller层
4.在service新建一个接口,接口的方法与mapper接口的方法一模一样(要除去@Param),然后再实现该接口的实例方法,方法中:加入mapper接口属性,并实现该属性的setter方法,再在配置文件中(service层配置文件)把该类注入:
public class BooksServiceImpl implements BooksService{
private BooksMapper booksMapper;
public void setBooksMapper(BooksMapper booksMapper) {
this.booksMapper = booksMapper;
}
@Override
public Books selectById(Integer id) {
return booksMapper.selectById(id);
}
......
}
=====================================================================
再在service层配置文件把该类注入:
<bean id="booksServiceImpl" class="com.springMVC.CRUD.service.BooksServiceImpl">
<property name="booksMapper" ref="booksMapper"/>
</bean>
class:新定义的接口的全类名
property -ref指向mapper接口
最后applicationContext.xml只有如下配置:
已忽略的文件头...
<!-- dao层:数据源+sqlSessionFactory-->
<import resource="classpath:spring-dao.xml"/>
<!-- service层:配置自动扫描service的bean,并将业务类注入进来-->
<import resource="classpath:spring-service.xml"/>
<!-- 注入dispatcherServlet.xml-->
<import resource="dispatcherServlet.xml"/>
具体的配置文件如下:我测试过:spring-dao.xml与spring-service.xml可以合在一起
spring-dao.xml
已忽略的文件头...
<context:component-scan base-package="com.lai.ssm.service"/>
<!-- 引入配置文件来配置数据库-->
<context:property-placeholder location="classpath:jdbc.properties"/>
<!-- spring用来控制业务逻辑等等 数据源 事务控制-->
<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driverClass}"/>
<!-- jdbc:mysql://000.000.000.000:3306/etc?serverTimezone=UTC-->
<property name="jdbcUrl" value="${jdbc.jdbcUrl}"/>
<property name="user" value="${jdbc.user}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 使用的数据源-->
<property name="dataSource" ref="dataSource"/>
<!-- 指定全局配置文件的位置-->
<property name="configLocation" value="classpath:MyBatisConfig.xml"/>
<property name="mapperLocations" value="classpath:mappers/BooksMapper.xml"/>
</bean>
<!-- 扫描MyBatis接口的实现,加入到IOC容器-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!-- 指定mapper接口的包名,一般在dao层-->
<property name="basePackage" value="com.lai.ssm.dao"/>
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
</bean>
<!-- 配置一个可以执行批量操作的bean-->
<bean id="sessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
<constructor-arg name="sqlSessionFactory" ref="sqlSessionFactory"/>
<constructor-arg name="executorType" value="BATCH"/>
</bean>
</beans>
spring-service.xml,注意注入进来的bean
已忽略的头文件...
<context:component-scan base-package="com.lai.ssm.service"/>
<!-- 将业务类注入进来-->
<bean id="BooksServiceImpl" class="com.lai.ssm.service.BooksServiceImpl">
<property name="booksMapper" ref="booksMapper"/>
<!--这里是service层定义了接口,接口的方法和dao层一样,然后实现类调用的是dao层的实现,实现类代码贴在最后-->
</bean>
<!-- =================================事务控制=================================-->
<!-- 事务管理器-->
<bean id="dataSourceTransactionManager"
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<!-- 控制数据库的事务,引进property属性里面-->
<property name="dataSource" ref="dataSource"/>
</bean>
</beans>
web.xml,注意spring和springMVC的配置文件的书写
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
version="4.0">
<!-- 配置spring配置文件,启动spring容器-->
<context-param>
<param-name>contextConfigLocation</param-name>
<!-- 配置spring配置文件的路径-->
<param-value>classpath:applicationContext.xml</param-value>
</context-param>
<listener>
<listener-class>org.springframework.web.context.ContextCleanupListener</listener-class>
</listener>
<!--配置springMVC配置文件-->
<!-- 配置DispatcherServlet-->
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
<!-- 是applicationContext.xml而不是dispatcherServlet.xml-->
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
<!-- 过滤器1: 解决中文乱码.字符过滤器 要放在所有filter之前-->
<filter>
<filter-name>encodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceRequestEncoding</param-name>
<param-value>true</param-value>
</init-param>
<init-param>
<param-name>forceResponseEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<session-config>
<session-timeout>15</session-timeout>
</session-config>
<!--过滤器2: 使用Rest风格的URI,可以把POST请求转化为DELETE 或 PUT-->
<filter>
<filter-name>HiddenHttpMethodFilter</filter-name>
<filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>HiddenHttpMethodFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
</web-app>
service实现的接口类:
package com.lai.ssm.service;
import com.lai.ssm.dao.BooksMapper;
import com.lai.ssm.pojo.Books;
import com.lai.ssm.pojo.BooksExample;
import com.lai.ssm.pojo.BooksKey;
import java.util.List;
public class BooksServiceImpl implements BooksService{
private BooksMapper booksMapper;
public void setBooksMapper(BooksMapper booksMapper) {
this.booksMapper = booksMapper;
}
@Override
public Books selectById(Integer id) {
return booksMapper.selectById(id);
}
@Override
public long countByExample(BooksExample example) {
return booksMapper.countByExample(example);
}
......一堆的数据库实现返回代码
}