本文主要介绍Spring集成MyBatis,并进行结合Junit进行单元测试的过程,以及在整合过程中遇到的问题。
准备环境:
a.操作系统 :win7 x64
b.基本软件:MySQL,Mybatis,Intelli idea
1.新建Maven项目,目录层级如下图
image.png
2、在pom.xml文件中加入整个项目需要的依赖包
<properties>
<java-version>1.8</java-version>
<org.springframework-version>4.3.14.RELEASE</org.springframework-version>
<org.aspectj-version>1.6.10</org.aspectj-version>
<org.slf4j-version>1.6.6</org.slf4j-version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${org.springframework-version}</version>
<exclusions>
<!-- Exclude Commons Logging in favor of SLF4j -->
<exclusion>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${org.springframework-version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${org.springframework-version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-test</artifactId>
<version>${org.springframework-version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>${org.springframework-version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${org.springframework-version}</version>
</dependency>
<dependency>
<groupId>commons-dbutils</groupId>
<artifactId>commons-dbutils</artifactId>
<version>1.6</version>
</dependency>
<!--Mybatis+Spring整合-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>1.3.2</version>
</dependency>
<!--mybatis依赖包-->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.4.6</version>
</dependency>
<dependency>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-core</artifactId>
<version>1.3.6</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.22</version>
</dependency>
<!-- AspectJ -->
<dependency>
<groupId>org.aspectj</groupId>
<artifactId>aspectjrt</artifactId>
<version>${org.aspectj-version}</version>
</dependency>
<!-- Logging -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${org.slf4j-version}</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>jcl-over-slf4j</artifactId>
<version>${org.slf4j-version}</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
<version>${org.slf4j-version}</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.15</version>
<exclusions>
<exclusion>
<groupId>javax.mail</groupId>
<artifactId>mail</artifactId>
</exclusion>
<exclusion>
<groupId>javax.jms</groupId>
<artifactId>jms</artifactId>
</exclusion>
<exclusion>
<groupId>com.sun.jdmk</groupId>
<artifactId>jmxtools</artifactId>
</exclusion>
<exclusion>
<groupId>com.sun.jmx</groupId>
<artifactId>jmxri</artifactId>
</exclusion>
</exclusions>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>javax.inject</groupId>
<artifactId>javax.inject</artifactId>
<version>1</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>4.0.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>2.8.2</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.8.2</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
</dependency>
</dependencies>
3、为了方便操作,Intelli idea 可以结合mybatis-generator-maven-plugin插件自动生成MyBatis代码。
首先,需要在pom.xml文件的build节点下加入该插件的配置。
<!-- mybatis-generator自动生成代码插件 -->
<plugin>
<groupId>org.mybatis.generator</groupId>
<artifactId>mybatis-generator-maven-plugin</artifactId>
<version>1.3.6</version>
<configuration>
<verbose>true</verbose>
<overwrite>true</overwrite>
</configuration>
</plugin>
其次,要在maven项目下的src/main/resources 目录下建立名为 generatorConfig.xml的配置文件,作为mybatis-generator-maven-plugin 插件的执行目标。
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN" "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
<!-- 数据库驱动 -->
<properties resource="jdbc.properties" />
<!-- 指定数据连接驱动jar地址 -->
<classPathEntry location="${driverPath}" />
<context id="DB2Tables" targetRuntime="MyBatis3">
<commentGenerator>
<property name="suppressDate" value="true" />
<!-- 是否去除自动生成的注释 true:是 : false:否 -->
<property name="suppressAllComments" value="true" />
</commentGenerator>
<!--数据库链接URL,用户名、密码 -->
<jdbcConnection driverClass="${driverClass}"
connectionURL="${jdbcUrl}" userId="${user}" password="${password}">
</jdbcConnection>
<javaTypeResolver>
<property name="forceBigDecimals" value="false" />
</javaTypeResolver>
<!-- 生成模型的包名和位置 -->
<javaModelGenerator targetPackage="${target_package}.pojo"
targetProject=".\src\main\java">
<property name="enableSubPackages" value="true" />
<property name="trimStrings" value="true" />
</javaModelGenerator>
<!-- 生成映射文件的包名和位置 -->
<sqlMapGenerator targetPackage="${target_package}.mapping"
targetProject=".\src\main\java">
<property name="enableSubPackages" value="true" />
</sqlMapGenerator>
<!-- 生成DAO的包名和位置 -->
<javaClientGenerator type="XMLMAPPER"
targetPackage="${target_package}.dao" targetProject=".\src\main\java">
<property name="enableSubPackages" value="true" />
</javaClientGenerator>
<!-- 要生成的表 tableName是数据库中的表名或视图名 domainObjectName是实体类名 -->
<table tableName="myuser" domainObjectName="User"
enableCountByExample="false" enableUpdateByExample="false"
enableDeleteByExample="false" enableSelectByExample="false"
selectByExampleQueryId="false">
<property name="useActualColumnNames" value="false" />
</table>
</context>
</generatorConfiguration>
上述配置spring数据源,需要在src/main/resources 目录下新增Jdbc.properties文件。文件内容如下:
注意,mysql-connector-java包的版本需要是6.0以下,否则会报错。
user=root
password=123
driverClass=com.mysql.jdbc.Driver
jdbcUrl=jdbc:mysql://192.168.100.63:3308/mysql
driverPath=C:\\Users\\ccc\\.m2\\repository\\mysql\\mysql-connector-java\\5.1.22\\mysql-connector-java-5.1.22.jar
target_package=com.sc
要生面的表myuser,在mysql中存在,具体结构如下
image.png
最后在intelli IDEA 的菜单栏,点击RUN-Edit Configurations,点击弹出窗口左上角的+号,新增Maven.为当前配置配置一个名称,这里命名为"generator",然后在 “Command line” 选项中输入“mybatis-generator:generate -e”。这里加了“-e ”选项是为了让该插件输出详细信息,帮助我们定位问题。
点击Apply。
image.png
image.png
点击运行geratorator,即可自动生成dao,pojo,mapping对应文件
image.png
4、上述生成MyBatis相关文件后,在src/main/resources 目录下新增spring-mybatis.xml
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
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">
<!-- 导入资源文件 -->
<context:property-placeholder location="classpath:jdbc.properties"/>
<!-- 扫描Impl包 -->
<context:component-scan base-package="com.sc.impl" />
<!-- 配置 spring 数据源 -->
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="username" value="${user}"></property>
<property name="password" value="${password}"></property>
<property name="url" value="${jdbcUrl}"></property>
<property name="driverClassName" value="${driverClass}"></property>
</bean>
<!-- spring和MyBatis完美整合,不需要mybatis的配置映射文件 -->
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<!-- 自动扫描mapping.xml文件 -->
<property name="mapperLocations" value="classpath*:com/sc/mapping/*.xml"></property>
</bean>
<!-- DAO接口所在包名,Spring会自动查找其下的类 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.sc.dao" />
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"></property>
</bean>
</beans>
5、因为MyBatis的xml映射文件和propertis文件都在src的下级目录下,所以需要在pom.xml的build节点下加入
<resources>
<!-- 编译之后包含xml -->
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
</resource>
<!-- 编译之后包含xml和properties -->
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*</include>
</includes>
</resource>
</resources>
6、创建service层
首先,新增接口UserServiceI
package com.sc.service;
import com.sc.pojo.User;
public interface UserServiceI {
/**
* 添加用户
* @param user
*/
void addUser(User user);
/**
* 根据用户id获取用户
* @param userId
* @return
*/
User getUserById(Integer userId);
}
其次,新增实现类UserServiceImpl
package com.sc.impl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.sc.dao.UserMapper;
import com.sc.pojo.User;
import com.sc.service.UserServiceI;
/**
* @author gacl
* 使用@Service注解将UserServiceImpl类标注为一个service
* service的id是userService
*/
@Service("userService")
public class UserServiceImpl implements UserServiceI {
/**
* 使用@Autowired注解标注userMapper变量,
* 当需要使用UserMapper时,Spring就会自动注入UserMapper
*/
@Autowired
private UserMapper userMapper;//注入dao
@Override
public void addUser(User user) {
userMapper.insert(user);
}
@Override
public User getUserById(Integer userId) {
return userMapper.selectByPrimaryKey(userId);
}
}
7、新增测试类,结合junit
package com.sc.test;
import com.sc.pojo.User;
import com.sc.service.UserServiceI;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MyBatisTest {
private UserServiceI userService;
/**
* 这个before方法在所有的测试方法之前执行,并且只执行一次
* 所有做Junit单元测试时一些初始化工作可以在这个方法里面进行
* 比如在before方法里面初始化ApplicationContext和userService
*/
@Before
public void before(){
//使用"spring.xml"和"spring-mybatis.xml"这两个配置文件创建Spring上下文
ApplicationContext ac = new ClassPathXmlApplicationContext("spring-mybatis.xml");
//从Spring容器中根据bean的id取出我们要使用的userService对象
userService = (UserServiceI) ac.getBean("userService");
}
@Test
public void testAddUser(){
User user = new User();
user.setUsername("123aaaaa");
user.setPasswd("aaaaa");
user.setAddress("龙田");
user.setEmail("sss");
user.setType(1);
userService.addUser(user);
User user1 = userService.getUserById(1);
System.out.println(user1);
}
}
执行结果:
image.png
8、SpringMVC集成MyBatis获取信息返回到jsp页面
添加Controller组件相关类:
package com.sc.controller;
import com.sc.impl.UserServiceImpl;
import com.sc.pojo.User;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
@Controller
@RequestMapping(value = "/user")
public class UserController {
@Resource
UserServiceImpl userService;
@RequestMapping(value = "/showUser")
public String getUser(HttpServletRequest request, Model model){
String userId = request.getParameter("id");
if(!userId.equals("")&&userId!=null){
System.out.println(userId+"-----------");
User user = userService.getUserById(Integer.parseInt(userId));
model.addAttribute("user",user);
}
return "showUser";
}
}
在web-info/config下新增配置文件 spring-mvc-servlet.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.2.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.2.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.2.xsd">
<!-- 扫描路径 -->
<context:component-scan base-package="com.sc.controller">
<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
<!-- 配置根视图 -->
<mvc:view-controller path="/" view-name="index"/>
<!-- 激活基于注解的配置 @RequestMapping, @ExceptionHandler,数据绑定 ,@NumberFormat ,
@DateTimeFormat ,@Controller ,@Valid ,@RequestBody ,@ResponseBody等 -->
<mvc:annotation-driven/>
<!-- 静态资源处理, css, js, imgs -->
<mvc:resources location="/assets/" mapping="/assets/**"></mvc:resources>
<!-- 视图层配置 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/view/"/>
<property name="suffix" value=".jsp"/>
</bean>
</beans>
在web.xml中加载上述配置文件:
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd "
version="3.0">
<display-name>Archetype Created Web Application</display-name>
<!-- Spring和mybatis的配置文件 -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-mybatis.xml</param-value>
</context-param>
<!-- 编码过滤器 -->
<filter>
<filter-name>encodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<async-supported>true</async-supported>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- Spring监听器 -->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- 防止Spring内存溢出监听器 -->
<listener>
<listener-class>org.springframework.web.util.IntrospectorCleanupListener</listener-class>
</listener>
<!-- Spring MVC servlet -->
<servlet>
<servlet-name>SpringMVC</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/config/spring-mvc-servlet.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
<async-supported>true</async-supported>
</servlet>
<servlet-mapping>
<servlet-name>SpringMVC</servlet-name>
<!-- 此处可以可以配置成*.do,对应struts的后缀习惯 -->
<url-pattern>/</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>/index.jsp</welcome-file>
</welcome-file-list>
<!-- 配置SESSION超时,单位是分钟 -->
<session-config>
<session-timeout>15</session-timeout>
</session-config>
</web-app>
启动tomcat,在浏览器中输入链接:http://localhost:8080/user/showUser?id=1
测试结果如下:
在整个整合过程中,遇到的问题如下:
1、org.apache.ibatis.binding.BindingException: Invalid bound statement (not found): com.sc.dao.UserMapper.selectByPrimaryKey。
具体错误信息如下:
image.png
解决方案:
需要强制将xml文件打包到war中,在pom.xml文件的bulid节点下添加以下代码
<resources>
<!-- 编译之后包含xml -->
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
</includes>
</resource>
</resources>
2、Could not resolve resource location pattern [classpath:com/sc/mapping/.xml]: class path resource [com/sc/mapping/] cannot be resolved to URL because it does not exist
解决方案:
在mybatis的配置文件下 扫描不到 xml文件
在spring-mybatis.xml中扫描xml的配置如下
需要将classpath 为 classpath
<bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
<property name="dataSource" ref="dataSource" />
<!-- 自动扫描mapping.xml文件 -->
<property name="mapperLocations" value="classpath*:com/sc/mapping/*.xml"></property>
</bean>
3、使用generator 自动生成重复MyBatis代码
java.lang.IllegalArgumentException: Result Maps collection already contains value for com.sc.dao.UserMapper.BaseResultMap
多次使用generator生成mybatis代码,在生成xxxMapper.xml文件后,再生成一次,新的内容会以追加的方式加入到原来的xxxMapper.xml文件中。
image.png
解决方案:
方法一:直接删除mapping目录下的**mapper.xml文件
方法二: 在IntrospectedTableMyBatis3Impl.getGeneratedXmlFiles方法中,isMergeable值被写死为true。而MyBatisGenerator.writeGeneratedXmlFile方法中使用到该属性,结果导致每次重新生成后都是追加。
为了不用修改源码,重新打包,造成包不一致,所以使用反射在运行时把isMergeable强制改成false,需要新增一个插件。
新增 OverIsMergeablePlugin 类继承PluginAdapter
package com.sc.utils;
import org.mybatis.generator.api.GeneratedXmlFile;
import org.mybatis.generator.api.IntrospectedTable;
import org.mybatis.generator.api.PluginAdapter;
import java.lang.reflect.Field;
import java.util.List;
public class OverIsMergeablePlugin extends PluginAdapter {
@Override
public boolean validate(List<String> warnings) {
return true;
}
@Override
public boolean sqlMapGenerated(GeneratedXmlFile sqlMap, IntrospectedTable introspectedTable) {
try {
Field field = sqlMap.getClass().getDeclaredField("isMergeable");
field.setAccessible(true);
field.setBoolean(sqlMap, false);
} catch (Exception e) {
e.printStackTrace();
}
return true;
}
}
将上述插件注入到配置generatorConfig.xml中
<plugin type="com.sc.utils.OverIsMergeablePlugin" />
注意添加的位置。
image.png
新增mybatis自动生成代码的测试类
注意:这里Main类引入的是 com.sun.javaws包下的,否则会空指针异常。
package com.sc.test;
import com.sun.javaws.Main;
import org.mybatis.generator.api.MyBatisGenerator;
import org.mybatis.generator.config.Configuration;
import org.mybatis.generator.config.xml.ConfigurationParser;
import org.mybatis.generator.internal.DefaultShellCallback;
import java.util.ArrayList;
import java.util.List;
public class GeneratorTest {
public static void main(String[] args) throws Exception {
List<String> warnings = new ArrayList<String>();
boolean overwrite = true;
ConfigurationParser cp = new ConfigurationParser(warnings);
Configuration config = cp.parseConfiguration(Main.class.getClassLoader().getResourceAsStream("generatorConfig.xml"));
DefaultShellCallback callback = new DefaultShellCallback(overwrite);
MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
myBatisGenerator.generate(null);
System.out.println("----ok----");
}
}
运行测试类,发现mapping目录下生成的**Mapper.xml没有自动追加,而是覆盖。
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