一、环境准备
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创建一个Web的Maven项目
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pom.xml添加Spring依赖
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.itheima</groupId> <artifactId>springmvc_03_request_mapping</artifactId> <version>1.0-SNAPSHOT</version> <packaging>war</packaging> <dependencies> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.1.0</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.2.10.RELEASE</version> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.apache.tomcat.maven</groupId> <artifactId>tomcat7-maven-plugin</artifactId> <version>2.1</version> <configuration> <port>80</port> <path>/</path> </configuration> </plugin> </plugins> </build> </project> -
创建对应的配置类
public class ServletContainersInitConfig extends AbstractAnnotationConfigDispatcherServletInitializer { protected Class<?>[] getServletConfigClasses() { return new Class[]{SpringMvcConfig.class}; } protected String[] getServletMappings() { return new String[]{"/"}; } protected Class<?>[] getRootConfigClasses() { return new Class[0]; } } @Configuration @ComponentScan("com.itheima.controller") public class SpringMvcConfig { } -
编写BookController和UserController
@Controller public class UserController { @RequestMapping("/save") @ResponseBody public String save(){ System.out.println("user save ..."); return "{'module':'user save'}"; } @RequestMapping("/delete") @ResponseBody public String save(){ System.out.println("user delete ..."); return "{'module':'user delete'}"; } } @Controller public class BookController { @RequestMapping("/save") @ResponseBody public String save(){ System.out.println("book save ..."); return "{'module':'book save'}"; } }
最终创建好的项目结构如下:
把环境准备好后，启动Tomcat服务器，后台会报错:
从错误信息可以看出:
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UserController有一个save方法，访问路径为
http://localhost/save -
BookController也有一个save方法，访问路径为
http://localhost/save -
当访问
http://localhost/save的时候，到底是访问UserController还是BookController?
二、问题分析
团队多人开发，每人设置不同的请求路径，冲突问题该如何解决?解决思路:为不同模块设置模块名作为请求路径前置
对于Book模块的save,将其访问路径设置http://localhost/book/save
对于User模块的save,将其访问路径设置http://localhost/user/save
这样在同一个模块中出现命名冲突的情况就比较少了。
三、设置映射路径
步骤1:修改Controller
@Controller public class UserController { @RequestMapping("/user/save") @ResponseBody public String save(){ System.out.println("user save ..."); return "{'module':'user save'}"; } @RequestMapping("/user/delete") @ResponseBody public String save(){ System.out.println("user delete ..."); return "{'module':'user delete'}"; } } @Controller public class BookController { @RequestMapping("/book/save") @ResponseBody public String save(){ System.out.println("book save ..."); return "{'module':'book save'}"; } }问题是解决了，但是每个方法前面都需要进行修改，写起来比较麻烦而且还有很多重复代码，如果/user后期发生变化，所有的方法都需要改，耦合度太高。
步骤2:优化路径配置
优化方案:
@Controller @RequestMapping("/user") public class UserController { @RequestMapping("/save") @ResponseBody public String save(){ System.out.println("user save ..."); return "{'module':'user save'}"; } @RequestMapping("/delete") @ResponseBody public String save(){ System.out.println("user delete ..."); return "{'module':'user delete'}"; } } @Controller @RequestMapping("/book") public class BookController { @RequestMapping("/save") @ResponseBody public String save(){ System.out.println("book save ..."); return "{'module':'book save'}"; } }小结
注意:
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当类上和方法上都添加了
@RequestMapping注解，前端发送请求的时候，要和两个注解的value值相加匹配才能访问到。 -
@RequestMapping注解value属性前面加不加
/都可以
