整合ssm框架，详细讲解

今天针对 SSMSpringSpringMVCMyBatis框架整合展开了学习学习内容如下我们在进行 JavaEE 开发时为了实现解耦和提高开发效率通常会采用 SSMSpringSpringMVCMyBatis框架整合的方案。Spring作为核心容器负责管理业务组件Service和持久层组件DAO/Repository并提供事务管理功能。SpringMVC作为表现层框架负责处理 HTTP 请求接收前端参数并返回视图或数据。MyBatis作为持久层框架负责简化数据库操作实现对象与数据库表的映射。SSM 框架整合的核心思路是Spring 整合 MyBatis将 MyBatis 的SqlSessionFactory交给 Spring 容器管理并扫描 Mapper 接口生成代理对象让 Service 层可以直接注入 Mapper 进行使用。SpringMVC 的配置配置前端控制器DispatcherServlet和处理器映射处理 Web 层的请求。1. 环境准备与依赖配置首先我们需要在pom.xml中引入 SSM 三大框架以及数据库驱动、连接池等必要的依赖。注意为了使用注解进行事务管理我们需要引入spring-aspects依赖。1dependencies 2 !-- Spring 上下文环境 -- 3 dependency 4 groupIdorg.springframework/groupId 5 artifactIdspring-context/artifactId 6 version5.3.15/version 7 /dependency 8 !-- Spring 事务 -- 9 dependency 10 groupIdorg.springframework/groupId 11 artifactIdspring-tx/artifactId 12 version5.3.15/version 13 /dependency 14 !-- Spring JDBC -- 15 dependency 16 groupIdorg.springframework/groupId 17 artifactIdspring-jdbc/artifactId 18 version5.3.15/version 19 /dependency 20 !-- SpringMVC -- 21 dependency 22 groupIdorg.springframework/groupId 23 artifactIdspring-webmvc/artifactId 24 version5.3.15/version 25 /dependency 26 27 !-- Druid 数据源 -- 28 dependency 29 groupIdcom.alibaba/groupId 30 artifactIddruid/artifactId 31 version1.2.8/version 32 /dependency 33 34 !-- MySQL 驱动 -- 35 dependency 36 groupIdmysql/groupId 37 artifactIdmysql-connector-java/artifactId 38 version8.0.28/version 39 /dependency 40 41 !-- MyBatis -- 42 dependency 43 groupIdorg.mybatis/groupId 44 artifactIdmybatis/artifactId 45 version3.5.9/version 46 /dependency 47 !-- MyBatis 与 Spring 整合包 -- 48 dependency 49 groupIdorg.mybatis/groupId 50 artifactIdmybatis-spring/artifactId 51 version2.0.7/version 52 /dependency 53 54 !-- Lombok -- 55 dependency 56 groupIdorg.projectlombok/groupId 57 artifactIdlombok/artifactId 58 version1.18.22/version 59 /dependency 60/dependencies2. 配置文件详解SSM 整合涉及三个主要的配置文件web.xmlWeb 容器配置、springmvc.xml表现层配置、applicationContext.xml业务与持久层配置。2.1 web.xml 配置这是 JavaWeb 的入口我们需要配置 Spring 的监听器和 SpringMVC 的前端控制器。1web-app 2 !-- 配置 Spring 监听器加载业务层配置 -- 3 listener 4 listener-classorg.springframework.web.context.ContextLoaderListener/listener-class 5 /listener 6 !-- 指定 Spring 配置文件位置 -- 7 context-param 8 param-namecontextConfigLocation/param-name 9 param-valueclasspath:applicationContext.xml/param-value 10 /context-param 11 12 !-- 配置 SpringMVC 前端控制器 -- 13 servlet 14 servlet-namedispatcher/servlet-name 15 servlet-classorg.springframework.web.servlet.DispatcherServlet/servlet-class 16 init-param 17 param-namecontextConfigLocation/param-name 18 param-valueclasspath:springmvc.xml/param-value 19 /init-param 20 load-on-startup1/load-on-startup 21 /servlet 22 servlet-mapping 23 servlet-namedispatcher/servlet-name 24 url-pattern//url-pattern 25 /servlet-mapping 26/web-app2.2 MyBatis 配置 (SqlMapConfig.xml)虽然大部分配置在 Spring 中完成但 MyBatis 的核心配置文件如别名、插件等仍需单独配置。1configuration 2 !-- 别名配置对应实体类包 -- 3 typeAliases 4 package namecom.xzit.entity/ 5 /typeAliases 6 !-- Mapper 映射文件位置 -- 7 mappers 8 package namecom.xzit.mapper/ 9 /mappers 10/configuration2.3 Spring 核心配置 (applicationContext.xml)这是整合的关键配置了数据源、SqlSessionFactory 和 Mapper 扫描。1beans xmlnshttp://www.springframework.org/schema/beans 2 xmlns:xsihttp://www.w3.org/2001/XMLSchema-instance 3 xmlns:contexthttp://www.springframework.org/schema/context 4 xmlns:txhttp://www.springframework.org/schema/tx 5 xsi:schemaLocation... 6 7 !-- 1. 加载数据库配置文件 -- 8 context:property-placeholder locationclasspath:db.properties/ 9 10 !-- 2. 组件扫描扫描 Service 和 Repository -- 11 context:component-scan base-packagecom.xzit/ 12 13 !-- 3. 配置数据源 Druid -- 14 bean iddataSource classcom.alibaba.druid.pool.DruidDataSource 15 property namedriverClassName value${jdbc.driver}/ 16 property nameurl value${jdbc.url}/ 17 property nameusername value${jdbc.username}/ 18 property namepassword value${jdbc.password}/ 19 /bean 20 21 !-- 4. 配置 SqlSessionFactory -- 22 bean idsqlSessionFactory classorg.mybatis.spring.SqlSessionFactoryBean 23 property namedataSource refdataSource/ 24 property nameconfigLocation valueclasspath:SqlMapConfig.xml/ 25 /bean 26 27 !-- 5. 配置 Mapper 扫描器生成代理对象 -- 28 bean classorg.mybatis.spring.mapper.MapperScannerConfigurer 29 property namebasePackage valuecom.xzit.mapper/ 30 !-- 如果 SqlSessionFactory 的 id 不是默认的需要指定 -- 31 property namesqlSessionFactoryBeanName valuesqlSessionFactory/ 32 /bean 33 34 !-- 6. 配置事务管理器 -- 35 bean idtransactionManager classorg.springframework.jdbc.datasource.DataSourceTransactionManager 36 property namedataSource refdataSource/ 37 /bean 38 !-- 开启注解事务 -- 39 tx:annotation-driven transaction-managertransactionManager/ 40/beans2.4 SpringMVC 配置 (springmvc.xml)配置视图解析器和注解驱动。1beans xmlnshttp://www.springframework.org/schema/beans 2 xmlns:xsihttp://www.w3.org/2001/XMLSchema-instance 3 xmlns:contexthttp://www.springframework.org/schema/context 4 xmlns:mvchttp://www.springframework.org/schema/mvc 5 xsi:schemaLocation... 6 7 !-- 扫描控制层组件 -- 8 context:component-scan base-packagecom.xzit.controller/ 9 10 !-- 开启 MVC 注解驱动 -- 11 mvc:annotation-driven/ 12 13 !-- 配置视图解析器 (如果使用 JSP) -- 14 bean classorg.springframework.web.servlet.view.InternalResourceViewResolver 15 property nameprefix value/WEB-INF/views// 16 property namesuffix value.jsp/ 17 /bean 18/beans3. 代码实战完成配置后我们编写一个简单的用户管理模块来测试整合是否成功。3.1 数据库表结构1CREATE TABLE user ( 2 id int NOT NULL AUTO_INCREMENT, 3 name varchar(255) DEFAULT NULL, 4 age int DEFAULT NULL, 5 PRIMARY KEY (id) 6);3.2 实体类 (Entity)1package com.xzit.entity; 2 3import lombok.Data; 4 5Data 6public class User { 7 private Integer id; 8 private String name; 9 private Integer age; 10}3.3 Mapper 接口与 XML接口1package com.xzit.mapper; 2 3import com.xzit.entity.User; 4import org.apache.ibatis.annotations.Mapper; 5import org.springframework.stereotype.Repository; 6 7import java.util.List; 8 9Repository 10public interface UserMapper { 11 void save(User user); 12 User findById(Integer id); 13 ListUser findAll(); 14}UserMapper.xml (放在 resources/mapper 目录下)1?xml version1.0 encodingUTF-8 ? 2!DOCTYPE mapper PUBLIC -//mybatis.org//DTD Mapper 3.0//EN http://mybatis.org/dtd/mybatis-3-mapper.dtd 3mapper namespacecom.xzit.mapper.UserMapper 4 insert idsave parameterTypeUser 5 INSERT INTO user(name, age) VALUES(#{name}, #{age}) 6 /insert 7 select idfindById resultTypeUser 8 SELECT * FROM user WHERE id #{id} 9 /select 10 select idfindAll resultTypeUser 11 SELECT * FROM user 12 /select 13/mapper3.4 Service 层1package com.xzit.service; 2 3import com.xzit.entity.User; 4import com.xzit.mapper.UserMapper; 5import org.springframework.beans.factory.annotation.Autowired; 6import org.springframework.stereotype.Service; 7import org.springframework.transaction.annotation.Transactional; 8 9import java.util.List; 10 11Service 12Transactional // 开启事务 13public class UserService { 14 15 Autowired 16 private UserMapper userMapper; 17 18 public void addUser(User user) { 19 userMapper.save(user); 20 // 如果这里抛出异常数据会回滚 21 } 22 23 public User getUserById(Integer id) { 24 return userMapper.findById(id); 25 } 26}3.5 Controller 层1package com.xzit.controller; 2 3import com.xzit.entity.User; 4import com.xzit.service.UserService; 5import org.springframework.beans.factory.annotation.Autowired; 6import org.springframework.stereotype.Controller; 7import org.springframework.web.bind.annotation.*; 8 9RestController // 等价于 Controller ResponseBody 10RequestMapping(/user) 11public class UserController { 12 13 Autowired 14 private UserService userService; 15 16 PostMapping(/add) 17 public String addUser(RequestBody User user) { 18 userService.addUser(user); 19 return success; 20 } 21 22 GetMapping(/{id}) 23 public User getUser(PathVariable Integer id) { 24 return userService.getUserById(id); 25 } 26}