配置范式演进：XML、JavaConfig 与 Spring Boot

1. XML 配置方式示例

1.1 项目结构

src/main/java └── crj └── example └── xml └── controller └── XmlDemoController.java src/main/webapp └── WEB-INF ├── views │ └── xmlDemo.jsp └── xml-servlet.xml

1.2 配置文件

web.xml

<web-appxmlns="http://xmlns.jcp.org/xml/ns/javaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"version="3.1"><!-- 配置 DispatcherServlet --><servlet><servlet-name>xmlDispatcher</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><init-param><param-name>contextConfigLocation</param-name><param-value>/WEB-INF/xml-servlet.xml</param-value></init-param><load-on-startup>1</load-on-startup></servlet><servlet-mapping><servlet-name>xmlDispatcher</servlet-name><url-pattern>/xml/*</url-pattern></servlet-mapping></web-app>

xml-servlet.xml

<beansxmlns="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 http://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd"><!-- 扫描控制器 --><context:component-scanbase-package="crj.example.xml.controller"/><!-- 启用 MVC 注解驱动 --><mvc:annotation-driven/><!-- 配置视图解析器 --><beanclass="org.springframework.web.servlet.view.InternalResourceViewResolver"><propertyname="prefix"value="/WEB-INF/views/"/><propertyname="suffix"value=".jsp"/></bean></beans>

1.3 控制器实现

XmlDemoController.java

packagecrj.example.xml.controller;importorg.springframework.stereotype.Controller;importorg.springframework.web.bind.annotation.RequestMapping;importorg.springframework.web.bind.annotation.ResponseBody;@Controller@RequestMapping("/xml")publicclassXmlDemoController{@RequestMapping("/demo")@ResponseBodypublicStringhandleRequest(){return"Response from XML configuration";}}

2. JavaConfig 配置方式示例

2.1 项目结构

src/main/java └── crj └── example └── javaconfig ├── config │ ├── JavaConfigWebInitializer.java │ └── JavaConfigAppConfig.java └── controller └── JavaConfigDemoController.java

2.2 配置文件

JavaConfigWebInitializer.java

packagecrj.example.javaconfig.config;importorg.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;publicclassJavaConfigWebInitializerextendsAbstractAnnotationConfigDispatcherServletInitializer{@OverrideprotectedClass<?>[]getRootConfigClasses(){returnnewClass[0];}@OverrideprotectedClass<?>[]getServletConfigClasses(){returnnewClass[]{JavaConfigAppConfig.class};}@OverrideprotectedString[]getServletMappings(){returnnewString[]{"/javaconfig/*"};}}

JavaConfigAppConfig.java

packagecrj.example.javaconfig.config;importorg.springframework.context.annotation.ComponentScan;importorg.springframework.context.annotation.Configuration;importorg.springframework.web.servlet.config.annotation.EnableWebMvc;importorg.springframework.web.servlet.config.annotation.WebMvcConfigurer;importorg.springframework.web.servlet.view.InternalResourceViewResolver;@Configuration@EnableWebMvc@ComponentScan(basePackages="crj.example.javaconfig.controller")publicclassJavaConfigAppConfigimplementsWebMvcConfigurer{publicvoidconfigureViewResolvers(){InternalResourceViewResolverviewResolver=newInternalResourceViewResolver();viewResolver.setPrefix("/WEB-INF/views/");viewResolver.setSuffix(".jsp");}}

2.3 控制器实现

JavaConfigDemoController.java

packagecrj.example.javaconfig.controller;importorg.springframework.stereotype.Controller;importorg.springframework.web.bind.annotation.RequestMapping;importorg.springframework.web.bind.annotation.ResponseBody;@Controller@RequestMapping("/javaconfig")publicclassJavaConfigDemoController{@RequestMapping("/demo")@ResponseBodypublicStringhandleRequest(){return"Response from JavaConfig configuration";}}

3. Spring Boot 配置方式示例

3.1 项目结构

src/main/java └── crj └── example └── springboot ├── SpringBootDemoApplication.java └── controller └── SpringBootDemoController.java

3.2 配置文件

SpringBootDemoApplication.java

packagecrj.example.springboot;importorg.springframework.boot.SpringApplication;importorg.springframework.boot.autoconfigure.SpringBootApplication;@SpringBootApplicationpublicclassSpringBootDemoApplication{publicstaticvoidmain(String[]args){SpringApplication.run(SpringBootDemoApplication.class,args);}}

3.3 控制器实现

SpringBootDemoController.java

packagecrj.example.springboot.controller;importorg.springframework.web.bind.annotation.RequestMapping;importorg.springframework.web.bind.annotation.ResponseBody;importorg.springframework.stereotype.Controller;@Controller@RequestMapping("/springboot")publicclassSpringBootDemoController{@RequestMapping("/demo")@ResponseBodypublicStringhandleRequest(){return"Response from Spring Boot configuration";}}

4. 静态资源配置最佳实践

4.1 配置静态资源映射

在JavaConfigAppConfig.java中添加：

@OverridepublicvoidaddResourceHandlers(ResourceHandlerRegistryregistry){registry.addResourceHandler("/static/**").addResourceLocations("classpath:/static/");}

5. 性能调优技巧

5.1 启用缓存

在JavaConfigAppConfig.java中添加：

@BeanpublicCacheManagercacheManager(){returnnewConcurrentMapCacheManager("springMvcCache");}

6. 测试对比

6.1 访问路径对比

6.2 性能对比

7. 项目运行准备

7.1 依赖配置（pom.xml）

<dependencies><!-- Spring MVC --><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>5.3.20</version></dependency><!-- Servlet API --><dependency><groupId>javax.servlet</groupId><artifactId>javax.servlet-api</artifactId><version>4.0.1</version><scope>provided</scope></dependency><!-- Spring Boot 依赖 --><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId><version>2.6.8</version></dependency></dependencies>

7.2 部署说明

• 使用 Tomcat 9+ 或 Spring Boot 内置 Tomcat 部署
• 访问路径示例：
  • XML 配置：http://localhost:8080/xml/demo
  • JavaConfig 配置：http://localhost:8080/javaconfig/demo
  • Spring Boot 配置：http://localhost:8080/springboot/demo

下一篇预告：
《控制器层精进：映射、绑定与类型转换》
将涵盖：

• @RequestMapping的高级使用场景
• 复杂参数绑定与类型转换
• 异步控制器与流式 API 处理