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一、回顾SpringMVC访问接口流程

1.容器加载分析

• 容器分析

  

• 手动注册WebApplicationContext

  public class ServletConfig extends AbstractDispatcherServletInitializer {@Overrideprotected WebApplicationContext createServletApplicationContext() {//获取SpringMVC容器AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();context.register(SpringMvcConfig.class);return context;}@Overrideprotected String[] getServletMappings() {return new String[]{"/"};}@Overrideprotected WebApplicationContext createRootApplicationContext() {return null;}
  }
  

2.容器加载过程分析

• tomcat 服务器启动的时候，加载ServletConfig类之后，做初始化web容器操作，相当于 web.xml

• 执行注册容器的方法,获取 SpringMVC容器 WebApplicationContext

  @Nullableprotected WebApplicationContext createRootApplicationContext() {Class<?>[] configClasses = this.getRootConfigClasses();if (!ObjectUtils.isEmpty(configClasses)) {AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();context.register(configClasses);return context;} else {return null;}}protected WebApplicationContext createServletApplicationContext() {AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();Class<?>[] configClasses = this.getServletConfigClasses();if (!ObjectUtils.isEmpty(configClasses)) {context.register(configClasses);}return context;}
  

• 通过@ComponentScan(“cn.sycoder.controller”) 加载 Controller 下面的bean 进 WebApplicationContext

  @RestController
  public class TestController {@GetMapping("/test/{id}")public String test(@PathVariable Long id) {return "ok:" + id;}
  }
  

• 把使用了 RequestMapping 注解的方法的 value — 对应一个方法，建立起了一对一映射关系（可以想象hashmap）

  • /test/{id} ---- test 方法

3.请求接口过程

• 访问 http://localhost:8082/test/1
• 匹配 springmvc 的 / servletMapping 规则，交给 springmvc 处理
• 解析 /test/1路径找到对应的 test 方法
• 执行方法
• 因为使用 RestController ，所以返回方法的返回值作为响应体返回给浏览器

4.SSM整合会出现bean界定不清楚问题

• SpringMVC 需要加载哪些bean?
  • controller 层（表现层即可）
• Spring 加载哪些bean?
  • service
  • dao

4.1如何处理

• 将spring配置注入到 web 容器中

  @Configuration
  @ComponentScan(value={"cn.sycoder.service","cn.sycoder.dao"})
  public class SpringConfig {
  }

  public class ServletConfig  extends AbstractAnnotationConfigDispatcherServletInitializer {@Overrideprotected Class<?>[] getRootConfigClasses() {return new Class[]{SpringConfig.class};}@Overrideprotected Class<?>[] getServletConfigClasses() {return new Class[]{SpringMvcConfig.class};}@Overrideprotected String[] getServletMappings() {return new String[]{"/"};}
  }
  

4.2验证两个容器的bean相互不干扰

• 验证代码

  @Test
  public void test(){AnnotationConfigApplicationContext applicationContext =new AnnotationConfigApplicationContext(SpringConfig.class);ITestService bean = applicationContext.getBean(ITestService.class);bean.get(1L);TestController bean1 = applicationContext.getBean(TestController.class);System.out.println(bean1.test(1L));
  }
  

二、SSM整合

1.SSM整合流程分析

• 概述SSM：Spring SpringMVC Mybatis

1.1创建工程

• 导入依赖

  • ssm 所需要的依赖包

• 配置 web 项目入口配置替换 web.xml（AbstractAnnotationConfigDispatcherServletInitializer）

  • 配置 Spring 配置类交给 web 容器管理

    @Overrideprotected Class<?>[] getRootConfigClasses() {return new Class[]{SpringConfig.class};}
    

  • 配置 SpringMVC 配置类交给 web 容器管理

    @Overrideprotected Class<?>[] getServletConfigClasses() {return new Class[]{SpringMvcConfig.class};}
    

  • 配置请求拦截规则,交给 springmvc 处理

    @Overrideprotected String[] getServletMappings() {return new String[]{"/"};}
    

1.2配置 Spring

• SpringConfig
  • @Configuration 标记Spring配置类，替换Spring-config-xml
  • @ComponetScan 扫描需要被Spring 管理的bean
  • @EnableTransactionManagment 启动管理事务支持
  • @PropertySource 引入db.properties 配置文件
• 配置 JdbcConfig 配置类
  • 使用德鲁伊 DataSource 数据源
  • 构建平台事务管理器 DataSourceTransactionManager
• 配置 MyBatis 配置类
  • 构建 SqlSessionFactoryBean
  • 指定 MapperScanner 设置 mapper 包扫描寻找 mapper.xml 文件

1.3配置 SpringMVC

• 配置SpringMvcConfig
  • @Configuration
  • @ComponentScan 只扫描 Controller
  • 开启SpringMVC 注解支持 @EnableWebMvc

1.4开发业务

• 使用注解
  • 注入bean 注解
    • @Autowired
  • @RestController
    • @GetMapping
      • @RequestParam
    • @PostMapping
      • @RequestBody
    • @DeleteMapping
      • @PathVariable
    • @PutMapping
  • @Service
    • @Transactional
  • junit
    • @RunWith
    • @ContextConfiguration
    • @Test

2.SSM整合

2.1导入依赖

• 依赖

  <dependencies><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>5.2.17.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>5.2.17.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-test</artifactId><version>5.2.17.RELEASE</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.6</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>1.3.0</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.29</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.1.16</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version><scope>test</scope></dependency><dependency><groupId>javax.servlet</groupId><artifactId>javax.servlet-api</artifactId><version>3.1.0</version><scope>provided</scope></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.9.0</version></dependency></dependencies>
  

2.2创建各目录结构

• 目录如下

  

2.3创建SpringConfig

• SpringConfig(在整合项目的时候不能扫描mvc的类，否则会出现创建容器失败)

  @Configuration
  @ComponentScan(value = {"cn.sycoder.service","cn.sycoder.dao"})
  @EnableTransactionManagement
  @PropertySource("classpath:db.properties")
  @Import({DbConfig.class,MybatisConfig.class})
  public class SpringConfig {
  }
  

2.4创建DbConfig配置类

• 创建数据库配置文件

  jdbc.url=jdbc:mysql://localhost:3306/ssm
  jdbc.driver=com.mysql.cj.jdbc.Driver
  jdbc.username=root
  jdbc.password=123456
  

• 创建DbConfig

  public class DbConfig {@Value("${jdbc.url}")private String url;@Value("${jdbc.driver}")private String driver;@Value("${jdbc.username}")private String username;@Value("${jdbc.password}")private String password;/*** 配置德鲁伊连接池* @return*/@Beanpublic DataSource dataSource(){DruidDataSource source = new DruidDataSource();source.setUrl(url);source.setDriverClassName(driver);source.setPassword(password);source.setUsername(username);return source;}@Beanpublic PlatformTransactionManager transactionManager(DataSource dataSource){DataSourceTransactionManager manager = new DataSourceTransactionManager();manager.setDataSource(dataSource);return manager;}}
  

2.5创建MybatisConfig配置类

• MyBatisConfig

  public class MybatisConfig {@Beanpublic SqlSessionFactoryBean sessionFactoryBean(DataSource dataSource){SqlSessionFactoryBean bean = new SqlSessionFactoryBean();bean.setDataSource(dataSource);bean.setTypeAliasesPackage("cn.sycoder.domain");return bean;}@Beanpublic MapperScannerConfigurer mapperScannerConfigurer(){MapperScannerConfigurer configurer = new MapperScannerConfigurer();configurer.setBasePackage("cn.sycoder.dao");return configurer;}
  }
  

2.6创建SpringMVC配置类

• SpringMvcConfig

  @Configuration
  @ComponentScan("cn.sycoder.controller")
  @EnableWebMvc
  public class SpringMvcConfig {
  }
  

2.7创建Web项目入口配置类

• ServletConfig

  public class ServletConfig extends AbstractAnnotationConfigDispatcherServletInitializer {@Overrideprotected Class<?>[] getRootConfigClasses() {return new Class[]{SpringConfig.class};//配置Spring交给Web 管理}@Overrideprotected Class<?>[] getServletConfigClasses() {return new Class[]{SpringMvcConfig.class};}@Overrideprotected String[] getServletMappings() {return new String[]{"/"};}
  }
  

3.功能开发

3.1创建数据库及表

• 创建 ssm 数据库

• 创建 item 表

  create table item
  (id bigint auto_increment,type varchar(64) null,name varchar(64) null,remark text null,constraint item_pkprimary key (id)
  );

3.2编写模型类

• 添加 lombok 依赖

  <dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.22</version>
  </dependency>
  

• 模型类

  @Data
  public class Item {private Long id;private String name;private String type;private String remark;
  }
  

3.3编写Mapper接口

• Mapper 接口

  @Repository
  public interface ItemMapper {@Insert("insert into item(name,type,remark) value(#{name},#{type},#{remark})")public int save(Item item);@Delete("delete from item where id = #{id}")public int delete(Long id);@Update("update item set name = #{name},type = #{type},remark=#{remark} where id=#{id}")public int update(Item item);@Select("select * from item where id = #{id}")public Item getById(Long id);@Select("select * from item")public List<Item> list();}
  

3.4编写Service接口和实现类

• Service 接口

  public interface IItemService {/*** 添加闲置物品方法* @param item* @return*/public boolean save(Item item);/*** 删除闲置物品* @param id* @return*/public boolean delete(Long id);/*** 更新闲置物品* @param item* @return*/public boolean update(Item item);/*** 查询闲置物品通过id* @param id* @return*/public Item getById(Long id);/*** 查询所有闲置商品* @return*/public List<Item> lists();
  }
  

• 定义接口实现类

  @Service
  public class ItemServiceImpl implements IItemService {@AutowiredItemMapper mapper;@Override@Transactionalpublic boolean save(Item item) {return mapper.save(item) > 0;}@Override@Transactionalpublic boolean delete(Long id) {return mapper.delete(id) >0;}@Override@Transactionalpublic boolean update(Item item) {return mapper.update(item) >0;}@Overridepublic Item getById(Long id) {return mapper.getById(id);}@Overridepublic List<Item> lists() {return mapper.list();}
  }
  

3.5编写Contorller类

• Controller

  @RestController
  @RequestMapping("/item")
  public class ItemController {@AutowiredIItemService service;@PostMappingpublic boolean save(@RequestBody Item item){return service.save(item);}@PutMappingpublic boolean update(@RequestBody Item item){return service.update(item);}@DeleteMapping("/{id}")public boolean delete(@PathVariable Long id){return service.delete(id);}@GetMapping("/{id}")public Item getById(@PathVariable Long id){return service.getById(id);}@GetMappingpublic List<Item> list(){return service.lists();}
  }
  

4.验证 ssm 整合结果

• 启动项目并且解决问题

  

• 修改Spring配置类

  @Configuration
  @ComponentScan(value = {"cn.sycoder.service","cn.sycoder.dao"})
  @EnableTransactionManagement
  @PropertySource("classpath:db.properties")
  @Import({DbConfig.class,MybatisConfig.class})
  public class SpringConfig {
  }
  

4.1添加item 数据

• 准备 item 数据

  {"name":"键盘","type":"电脑外设","remark":"9成新，半价卖"}
  

  {"name":"笔记本","type":"电脑","remark":"9成新，8折出售"}
  

  {"name":"鞋子","type":"收藏鞋","remark":"科比签名的，独一无二"}
  

• 添加数据

  

4.2修改数据

• 准备数据

  {"id":4,"name":"二手鞋子","type":"废鞋","remark":"破鞋子"}
  

• 修改操作

  

4.3查询单个数据

• 查询id=4的物品

  

4.4删除单个数据

• 删除id=4的物品

  

4.5查询全部数据操作

• 查询全部

  

5.整合单元测试

• 目录结构

  

• 新建测试类

  @RunWith(SpringJUnit4ClassRunner.class)
  @ContextConfiguration(classes = SpringConfig.class)
  public class ItemTest {@AutowiredIItemService service;@Testpublic void save(){Item item = new Item();item.setName("单元测试");item.setRemark("单元测试");item.setType("单元测试");boolean save = service.save(item);System.out.println(save);}@Testpublic void update(){Item item = new Item();item.setId(5L);item.setName("单元测试");item.setRemark("单元测试");item.setType("单元测试");boolean save = service.update(item);System.out.println(save);}@Testpublic void getById(){Item byId = service.getById(5L);System.out.println(byId);}@Testpublic void list(){List<Item> lists = service.lists();System.out.println(lists);}
  }
  

三、项目实战中细节问题

1.导入前端资源

1.1静态资源拦截处理

• 设置访问 index 访问主页

  @Controller
  public class IndexController {@RequestMapping("/index")public String index(){System.out.println("----------------");return "/pages/items.html";}}
  

• 出现静态资源被拦截问题

  @Configuration
  public class StaticSupport extends WebMvcConfigurationSupport {@Overrideprotected void addResourceHandlers(ResourceHandlerRegistry registry) {registry.addResourceHandler("/pages/**").addResourceLocations("/pages/");registry.addResourceHandler("/js/**").addResourceLocations("/js/");registry.addResourceHandler("/css/**").addResourceLocations("/css/");registry.addResourceHandler("/plugins/**").addResourceLocations("/plugins/");}
  }
  

• 将 staticSupport 交给 SpringMvc 管理

  @Configuration
  @ComponentScan(value = {"cn.sycoder.controller","cn.sycoder.config"})
  @EnableWebMvc
  public class SpringMvcConfig {
  }
  

1.2项目实现

• 保存方法

  handleAdd () {console.log("========")axios.post("/item",this.formData).then((res)=>{//todo})
  },
  

• 列表查询

  getAll() {axios.get("/item",).then((res)=>{this.dataList = res.data;})
  },
  

• 删除操作

  handleDelete(row) {axios.delete("/item/"+row.id).then((res)=>{//todo})
  }