SSM整合_年轻人的第一个增删改查_基础环境搭建
写在前面
GitHub：https://github.com/say-hey/ssm_crud
Gitee：https://gitee.com/say-hey/ssm_crud
有用吗？对于学完Spring、SpringMVC、Mybatis还无从下手的同学来说这是一个很好引子。对于正在学习同一个案例的同学，可能解决一些问题。对于需要这个案例的同学可以直接获取。
有什么？：xml配置文件编写，引入一个简单的前端框架，使用MyBatis Generator逆向工程生成一些代码，使用框架简单快速搭建一个页面，好用的分页工具PageHelper，简单的前后端分离，发送ajax请求，利用json传递数据，增、删、改、查的简单实现。
简单吗？内容很简单，涉及Java代码不多，但是对于新手来说，最困难的部分是各种环境搭建、配置文件、版本冲突，如果能够根据错误提示动手解决，那就是一大进步。
怎么学？如果有时间可以在B站搜索：ssm整合crud，雷丰阳讲的。如果想看到每个功能的实现过程和源码，可以在这里学习，每个步骤都有注释。也可以作为复习快速浏览。
什么样？如下图：
1、基础环境搭建
不同编译器创建工程稍有不同，大致目录结构
ssm_crud
src
main
java
resources
webapp
WEB-INF
views
web.xml
index.jsp
pom.xml
pom.xml
目前的依赖只保证基本功能，后续使用其他功能需要再引入依赖
http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
4.0.0 <groupId>com.ssm</groupId> <artifactId>ssm_crud</artifactId> <version>1.0-SNAPSHOT</version> <packaging>war</packaging> <name>ssm_crud Maven Webapp</name> <!-- FIXME change it to the project's website --> <url>http://www.example.com</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> </properties> <!-- 引入jar包 --> <!-- spring,springmvc,mybatis,数据库连接池c3p0,数据库驱动包 --> <dependencies> <!-- spring-webmvc 包含spring和springmvc --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.2.1.RELEASE</version> </dependency> <!-- spring数据库驱动 spring-jdbc --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>5.2.1.RELEASE</version> </dependency> <!-- spring面向切面编程 spring-aspects --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aspects</artifactId> <version>5.2.1.RELEASE</version> </dependency> <!-- spring 单元测试 --> <!-- https://mvnrepository.com/artifact/org.springframework/spring-test --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-test</artifactId> <version>5.2.1.RELEASE</version> <scope>provided</scope> </dependency>
</dependencies> <!-- idea创建maven项目自动生成 --> <build> <finalName>ssm_crud</finalName> <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) --> <plugins> <plugin> <artifactId>maven-clean-plugin</artifactId> <version>3.1.0</version> </plugin> <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging --> <plugin> <artifactId>maven-resources-plugin</artifactId> <version>3.0.2</version> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.0</version> </plugin> <plugin> <artifactId>maven-surefire-plugin</artifactId> <version>2.22.1</version> </plugin> <plugin> <artifactId>maven-war-plugin</artifactId> <version>3.2.2</version> </plugin> <plugin> <artifactId>maven-install-plugin</artifactId> <version>2.5.2</version> </plugin> <plugin> <artifactId>maven-deploy-plugin</artifactId> <version>2.8.2</version> </plugin> </plugins> </pluginManagement> </build><!-- MyBatis --> <!-- mybatis --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.5.3</version> </dependency> <!-- spring和mybatis整合 mybatis-spring --> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>2.0.3</version> </dependency> <!-- 数据库连接池 驱动，两个数据源配置名不同，需要注意 --> <!-- c3p0数据源 --> <!--老版 <dependency> <groupId>c3p0</groupId> <artifactId>c3p0</artifactId> <version>0.9.1.2</version> </dependency> --> <!-- <dependency>--> <!-- <groupId>com.mchange</groupId>--> <!-- <artifactId>c3p0</artifactId>--> <!-- <version>0.9.5.5</version>--> <!-- </dependency>--> <!-- druid数据源 --> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.2.8</version> </dependency> <!-- mysql-connector-java 注意:要和MySQL统一版本,MySQL5,MySQL8 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <!-- 8.0.21 --> <version>8.0.18</version> </dependency> <!-- web项目其他包(jstl,servlet-api,junit) --> <dependency> <groupId>jstl</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <!-- Servlet api 是运行时需要,服务器中有,不需要打包,就配置<scope>provided</scope> --> <!-- servlet-api是3.0之前版本,java.servlet-api是3.0之后版本 --> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>4.0.1</version> <scope>provided</scope> </dependency> <!-- junit4测试--> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope> </dependency> <!-- junit5测试--> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter</artifactId> <version>RELEASE</version> <scope>compile</scope> </dependency>Bootstrap官网下载：起步 · Bootstrap v3 中文文档 | Bootstrap 中文网 (bootcss.com)
webapp目录下创建static目录，将
bootstrap-3.3.7-dist整个文件夹放入在static目录下引入
jquery-1.12.4.js文件在webapp目录下的
index.jsp中使用，只需要查看文档添加相应的class样式ssm_crud src main java resources webapp static bootstrap-3.3.7-dist jquery-1.12.4.js WEB-INF views web.xml index.jsp pom.xml <%-- 解决乱码 --%> <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <html> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <head> <script src="static/jquery-1.12.4.js"></script> <script src="static/bootstrap-3.3.7-dist/js/bootstrap.min.js"></script> <link href="static/bootstrap-3.3.7-dist/css/bootstrap.min.css" rel="stylesheet"> </head> <body> <h2>Hello World!</h2> <button type="button" class="btn btn-primary">（首选项）Primary</button> </body> </html>将
index.jsp在Tomcat中运行根据Tomcat设置端口访问
http://localhost:[端口号]/index.jsp会出现带有Bootstrap样式的按钮
配置文件是到目前为止，后续使用功能再添加
虽然后面SpringBoot、SpringCloud配置文件变少了，但配置文件有助于理解框架的结构和功能
使用不同Spring版本，部分配置文件可能不同，下面是Spring 5
web.xml
<!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>
<!-- 标签按顺序编写 -->
<display-name>Archetype Created Web Application</display-name>
<!-- 1.启动spring的容器 -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param>
<!-- 2.字符编码过滤器 ,放在最前面执行-->
<filter>
<filter-name>characterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<!-- 配置编码格式 -->
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<!-- 设置响应和请求格式都为true -->
<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>
<!-- 3.使用REST风格URI,将普通的POST请求转为DELETE,GET -->
<filter>
<filter-name>hiddenHttpMethodFilter</filter-name>
<filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
</filter>
<!-- 添加能直接处理PUT请求的过滤器 -->
<!-- HttpPutFormContentFilter过时了，使用 FormContentFilter能支持PUT和DELETE-->
<filter>
<filter-name>formContentFilter</filter-name>
<filter-class>org.springframework.web.filter.FormContentFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>formContentFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>characterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>hiddenHttpMethodFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- 4.监听器,项目启动指定加载某spring配置文件,用于初始化 -->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>
<!-- 5.SpringMVC前端控制器, 拦截所有请求-->
<!-- The front controller of this Spring Web application, responsible for handling all application requests -->
<servlet>
<servlet-name>springDispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<!-- 指定springmvc配置文件 -->
<param-value>classpath:springmvc.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
</servlet>
<!-- Map all requests to the DispatcherServlet for handling -->
<servlet-mapping>
<servlet-name>springDispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>applicationContext.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:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
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/aop https://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd">
<!-- spring配置文件,主要配置业务逻辑有关 -->
<!-- 数据源,事务控制,mybatis整合 -->
<!-- 自动扫描组件,但是不扫描Controller,Controller让springmvc扫描 -->
<context:component-scan base-package="com.ssm">
<context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
<!-- 引入外部配置文件 -->
<context:property-placeholder location="classpath:dbconfig.properties"/>
<!-- 数据源 C3P0 -->
<!-- <bean id="pooledDataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">-->
<!-- <property name="driverClass" value="${jdbc.driver}"/>-->
<!-- <property name="jdbcUrl" value="${jdbc.url}"/>-->
<!-- <property name="user" value="${jdbc.user}"/>-->
<!-- <property name="password" value="${jdbc.password}"/>-->
<!-- </bean>-->
<!-- druid数据源 -->
<bean id="pooledDataSource" class="com.alibaba.druid.pool.DruidDataSource">
<property name="driverClassName" value="${jdbc.driverClassName}"/>
<property name="url" value="${jdbc.jdbcUrl}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</bean>
<!-- 配置mybatis整合 -->
<bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 指定mybatis全局配置文件 -->
<property name="configLocation" value="classpath:mybatis-config.xml"/>
<!-- 数据源 -->
<property name="dataSource" ref="pooledDataSource"/>
<!-- 指定mybatis,mapper文件位置 -->
<property name="mapperLocations" value="classpath:mapper/*.xml"></property>
</bean>
<!-- 配置扫描器,将mybatis接口的实现加入到IOC容器中 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<!-- 扫描所有dao接口实现,加入IOC容器中 -->
<property name="basePackage" value="com.ssm.dao"></property>
</bean>
<!-- 配置一个可以执行批量sqlSession -->
<bean id="sqlSessionTemplate" class="org.mybatis.spring.SqlSessionTemplate">
<constructor-arg name="sqlSessionFactory" ref="sqlSessionFactoryBean"/>
<!-- 使用批量执行器 -->
<constructor-arg name="executorType" value="BATCH"/>
</bean>
<!-- 事务控制的配置 -->
<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
<property name="dataSource" ref="pooledDataSource"></property>
</bean>
<!-- 开启基于注解/xml的事务,重要的用xml配合 -->
<aop:config>
<!-- 切入点表达式 被匹配中的都是切入点 之后被事务增强-->
<aop:pointcut expression="execution(* com.ssm.service..*(..))" id="txPoint"/>
<!-- 配置事务增强 -->
<aop:advisor advice-ref="txAdvice" pointcut-ref="txPoint"/>
</aop:config>
<!-- 利用事务管理器transactionManager,将上下两个配置链接一起,利用切入点表达式进行切入,之后的方法看下面 -->
<!-- 配置事务增强 事务如何切入--><!-- 切入点表达式之后怎么切,要看下面的方法 -->
<tx:advice id="txAdvice" transaction-manager="transactionManager">
<tx:attributes>
<!-- * 代表所有方法都是事务方法 -->
<tx:method name="*"/>
<!-- 以get开头的方法 read-only只读-->
<tx:method name="get*" read-only="true"/>
</tx:attributes>
</tx:advice>
</beans>dbconfig.properties
#c3p0数据源配置，使用jdbc前缀防止冲突
#jdbc.driver=com.mysql.cj.jdbc.Driver
#jdbc.url=jdbc:mysql://localhost:3306/ssm_crud?serverTimezone=UTC&useSSL=false
#jdbc.user=root
#jdbc.password=123456
#druid数据源配置，mysql 5和mysql 8配置信息不同
jdbc.driverClassName=com.mysql.cj.jdbc.Driver
jdbc.jdbcUrl=jdbc:mysql://localhost:3306/ssm_crud?serverTimezone=UTC&useSSL=false
jdbc.username=root
jdbc.password=123456mybatis-config.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<settings>
<!-- 驼峰命名规则 从经典数据库列名 A_COLUMN 到经典 Java 属性名 aColumn 的类似映射。 -->
<setting name="mapUnderscoreToCamelCase" value="true"/>
</settings>
<typeAliases>
<package name="com.ssm.bean"/>
</typeAliases>
</configuration>springmvc.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.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">
<!-- SpringMVC配置文件:包含网站跳转 -->
<!-- 自动扫描组件,视图解析器,两个mvc标准配置 -->
<!-- 自动扫描组件 ***-->
<context:component-scan base-package="com.ssm" use-default-filters="false">
<!-- use-default-filters="false" 禁用默认扫描包 -->
<!-- 所以一般做法是，在SpringMVC的配置里，只扫描Controller层，
Spring配置 中扫描所有包，但是排除Controller层。 -->
<!-- include-filter 只扫描指定注解类 -->
<context:include-filter type="annotation"
expression="org.springframework.stereotype.Controller"/>
</context:component-scan>
<!-- 配置视图解析器 -->
<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/views/"/>
<property name="suffix" value=".jsp"/>
</bean>
<!-- 两个标准配置 -->
<!-- 将springmvc不能处理的请求交给Tomcat 静态页面，如html,css,js,images可以访问-->
<mvc:default-servlet-handler/>
<!-- 支持springmvc更高级功能,如JSR03校验,快捷ajax请求...映射动态请求
注解驱动，以使得访问路径与方法的匹配可以通过注解配置-->
<mvc:annotation-driven/>
</beans>一个库
ssm_crud，两个表tbl_dept、tbl_emp
-- Table structure for tbl_dept
DROP TABLE IF EXISTS
tbl_dept;
CREATE TABLEtbl_dept(
dept_idint(11) NOT NULL AUTO_INCREMENT,
dept_namevarchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
PRIMARY KEY (dept_id) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 2 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
-- Table structure for tbl_emp
DROP TABLE IF EXISTS
tbl_emp;
CREATE TABLEtbl_emp(
emp_idint(11) NOT NULL AUTO_INCREMENT,
emp_namevarchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
genderchar(1) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
emailvarchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
d_idint(11) NULL DEFAULT NULL,
PRIMARY KEY (emp_id) USING BTREE,
INDEXfk_emp_dept(d_id) USING BTREE,
CONSTRAINTfk_emp_deptFOREIGN KEY (d_id) REFERENCEStbl_dept(dept_id) ON DELETE RESTRICT ON UPDATE RESTRICT
) ENGINE = InnoDB AUTO_INCREMENT = 1036 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;
逆向生成
根据现有的数据库结构生成对象的JavaBean、Dao接口、Mapper.xml等
在ssm_crud根目录下创建mbg.xml配置文件
<?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>
</generatorConfiguration><context id="DB2Tables" targetRuntime="MyBatis3"> <!-- 生成toString方法--> <plugin type="org.mybatis.generator.plugins.ToStringPlugin"/> <!-- 禁止自动生成注释 --> <commentGenerator> <!-- 编码格式 --> <property name="javaFileEncoding" value="UTF-8"/> <property name="suppressAllComments" value="true"/> </commentGenerator> <!-- 配置数据库连接 --> <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/ssm_crud?serverTimezone=UTC&amp;useSSL=false" userId="root" password="123456"/> <!--数据库BigDecimals字段在java中定义 --> <javaTypeResolver> <property name="forceBigDecimals" value="false"/> </javaTypeResolver> <!-- 指定JavaBean生成位置 --> <javaModelGenerator targetPackage="com.ssm.bean" targetProject="src\main\java"/> <!-- 指定sql映射文件生产位置 --> <sqlMapGenerator targetPackage="mapper" targetProject="src\main\resources"/> <!-- 指定dao接口生成的位置,mapper接口 --> <javaClientGenerator type="XMLMAPPER" targetPackage="com.ssm.dao" targetProject="src\main\java"/> <!-- 指定每个表生成策略 --> <table tableName="tbl_emp" domainObjectName="Employee"></table> <table tableName="tbl_dept" domainObjectName="Department"></table> </context>在
com.ssm.test包中任意创建一个测试方法，然后运行/** * MyBatis Generator逆向工程 */ public class MBGTest { public static void main(String[] args) throws InvalidConfigurationException, IOException, XMLParserException, SQLException, InterruptedException { List<String> warnings = new ArrayList<String>(); boolean overwrite = true; File configFile = new File("mbg.xml"); ConfigurationParser cp = new ConfigurationParser(warnings); Configuration config = cp.parseConfiguration(configFile); DefaultShellCallback callback = new DefaultShellCallback(overwrite); MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings); myBatisGenerator.generate(null); } }之后项目自动生成文件，主要分三部分
- 每个表生成对应JavaBean和对应的查询条件Example
- Dao接口
- Mapper.xml文件
联表查询
自动生成的功能不能满足指定的查询条件，所以需要修改
实现一条sql完成联表查询，在逆向工程的基础上，需要修改以下地方
JavaBean
Department
package com.ssm.bean; public class Department { private Integer deptId;
}private String deptName; //如果用了构造器,一定要写无参构造器 public Department() { super(); } public Department(Integer deptId, String deptName) { super(); this.deptId = deptId; this.deptName = deptName; } //get/set/toStringEmployee
package com.ssm.bean; public class Employee { private Integer empId;
}private String empName; private String gender; private String email; private Integer dId; // 增加联合查询 private Department department; // 如果用了构造器,一定要写无参构造器 public Employee() { super(); } // 不加Department的属性 public Employee(Integer empId, String empName, String gender, String email, Integer dId) { super(); this.empId = empId; this.empName = empName; this.gender = gender; this.email = email; this.dId = dId; } // get/set/toString
Dao
EmployeeMapper
public interface EmployeeMapper { //...
}//新增两个查询方法,用于联合查询 List<Employee> selectByExampleWithDept(EmployeeExample example); Employee selectByPrimaryKeyWithDept(Integer empId);
Mapper
EmployeeMapper.xml
<mapper namespace="com.ssm.dao.EmployeeMapper"> <!-- ... -->
</mapper><!-- 新增两个查询方法,在查empt员工时,同时查出部门联合查询 --> <!-- 条件查询 List<Employee> selectByExampleWithDept(EmployeeExample example); --> <!-- 查询主键 Employee selectByPrimaryKeyWithDept(Integer empId); --> <!-- 新增 查询empty和dept的列 --> <sql id="WithDept_Column_List"> e.emp_id, e.emp_name, e.gender, e.email, e.d_id, d.dept_id, d.dept_name </sql> <!-- 新增 处理自定义的返回映射 部门信息封装--> <resultMap type="com.ssm.bean.Employee" id="WithDeptResultMap"> <id column="emp_id" jdbcType="INTEGER" property="empId" /> <result column="emp_name" jdbcType="VARCHAR" property="empName" /> <result column="gender" jdbcType="CHAR" property="gender" /> <result column="email" jdbcType="VARCHAR" property="email" /> <result column="d_id" jdbcType="INTEGER" property="dId" /> <!-- 联合查询 部门信息封装 --> <association property="department" javaType="com.ssm.bean.Department"> <id column="dept_id" property="deptId"/> <result column="dept_name" property="deptName"/> </association> </resultMap> <!-- 自定义 根据条件查询 联表 员工+部门 按照逆向模板修改--> <select id="selectByExampleWithDept" resultMap="WithDeptResultMap"> select <if test="distinct"> distinct </if> <!-- 查询条件,只用自定义的,包含两个表的字段 --> <include refid="WithDept_Column_List"/> from tbl_emp e left join tbl_dept d on e.d_id = d.dept_id <!-- 后面语句用来处理条件 --> <if test="_parameter != null"> <include refid="Example_Where_Clause"/> </if> <!-- 原装，应该是复杂查询中的排序条件 <if test="orderByClause != null"> order by ${orderByClause} </if> --> order by e.emp_id </select> <!-- 自定义 根据主键查询 联表 员工+部门 --> <select id="selectByPrimaryKeyWithDept" resultMap="WithDeptResultMap"> select <include refid="WithDept_Column_List"/> from tbl_emp e left join tbl_dept d on e.d_id = d.dept_id where emp_id = #{empId,jdbcType=INTEGER} </select> <!-- ... -->
批量插入
在
com.ssm.test中任意创建测试类，测试sql连接并添加数据//如果您想在测试中使用Spring测试框架功能（例如）@MockBean，则必须使用@ExtendWith(SpringExtension.class)。它取代了不推荐使用的JUnit4@RunWith(SpringJUnit4ClassRunner.class) @ExtendWith(SpringExtension.class) @ContextConfiguration(locations = {"classpath:applicationContext.xml"}) public class MapperTest {
// departmentMapper.insertSelective(new Department(null, "开发部")); // departmentMapper.insertSelective(new Department(null, "测试部"));@Autowired DepartmentMapper departmentMapper; @Autowired EmployeeMapper employeeMapper; //批量sqlSession @Autowired SqlSessionTemplate sqlSessionTemplate; @Test public void test(){ //Employee employee = employeeMapper.selectByPrimaryKeyWithDept(1); //System.out.println(employee); //1.插入部门
// employeeMapper.insertSelective(new Employee(null, "Tom", "M", "Tom@123.com", 1));//2.插入员工
}//3.批量插入 //使用sqlSessionTemplat可以实现批量,不使用就不是 EmployeeMapper eMapperTemplat = sqlSessionTemplate.getMapper(EmployeeMapper.class); for(int i = 0 ; i <= 1000 ; i++) { String uuid = UUID.randomUUID().toString().substring(0, 5) + i; //这里继续使用employeeMapper就不行 //employeeMapper.insertSelective(new Employee(null, uuid, "M", uuid+"@123.com", 1)); //使用employeeMapperTemplat批量插入 eMapperTemplat.insertSelective(new Employee(null, uuid, "M", uuid+"@123.com", 1)); } }
到目前为止，Spring、SpringMVC、MyBatis都已经配置完成，各功能可以连通，可以进行编写增删改查的代码了。目前目录结构如下
ssm_crud
src
main
java
com.ssm.bean
Department.java
EmployeeExample.java
Employee.java
DepartmentExample.java
com.ssm.dao
EmployeeMapper.java
DepartmentMapper.java
com.ssm.service
com.ssm.controller
com.ssm.test
MapperTest.java
MBGTest.java
com.ssm.utils
resources
mapper
DepartmentMapper.xml
EmployeeMapper.xml
applicationContext.xml
dbconfig.properties
mybatis-config.xml
springmvc.xml
webapp
static
bootstrap-3.3.7-dist
jquery-1.12.4.js
WEB-INF
views
web.xml
index.jsp
pom.xml
mbg.xml手机扫一扫
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