Java案例如何整合SpringMVC?

wen java案例 21

本文目录导读:

Java案例如何整合SpringMVC?

  1. 传统XML配置方式(适用于Servlet 3.0以下容器)
  2. 全注解配置方式(推荐,适用于Servlet 3.0+)
  3. Spring Boot方式(最简捷)
  4. 整合关键要点
  5. 推荐整合方案

在Java中整合SpringMVC有多种方式,我为你详细介绍最常见的几种方案:

传统XML配置方式(适用于Servlet 3.0以下容器)

项目结构

src/main/java
├── com/example/controller
│   └── UserController.java
├── com/example/config
│   └── WebConfig.java
src/main/webapp/WEB-INF
├── web.xml
└── views
    └── index.jsp

web.xml配置

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="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">
    <!-- 1. 配置Spring根容器 -->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <!-- 2. 配置SpringMVC前端控制器 -->
    <servlet>
        <servlet-name>dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:springmvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

SpringMVC配置文件(springmvc.xml)

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="...">
    <!-- 开启注解驱动 -->
    <mvc:annotation-driven/>
    <!-- 扫描Controller -->
    <context:component-scan base-package="com.example.controller"/>
    <!-- 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>
    <!-- 静态资源处理 -->
    <mvc:resources mapping="/static/**" location="/static/"/>
</beans>

全注解配置方式(推荐,适用于Servlet 3.0+)

启动类(实现WebApplicationInitializer)

package com.example.config;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;
import javax.servlet.ServletContext;
import javax.servlet.ServletRegistration;
public class WebAppInitializer implements WebApplicationInitializer {
    @Override
    public void onStartup(ServletContext servletContext) {
        // 1. 创建Spring应用上下文
        AnnotationConfigWebApplicationContext context = 
            new AnnotationConfigWebApplicationContext();
        // 2. 注册配置类
        context.register(WebConfig.class);
        // 3. 创建DispatcherServlet
        DispatcherServlet dispatcherServlet = new DispatcherServlet(context);
        // 4. 注册Servlet
        ServletRegistration.Dynamic registration = 
            servletContext.addServlet("dispatcher", dispatcherServlet);
        registration.setLoadOnStartup(1);
        registration.addMapping("/");
    }
}

SpringMVC配置类

package com.example.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
import org.springframework.web.servlet.view.InternalResourceViewResolver;
@Configuration
@EnableWebMvc
@ComponentScan(basePackages = "com.example.controller")
public class WebConfig implements WebMvcConfigurer {
    // 配置视图解析器
    @Bean
    public ViewResolver viewResolver() {
        InternalResourceViewResolver resolver = 
            new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".jsp");
        resolver.setExposeContextBeansAsAttributes(true);
        return resolver;
    }
    // 配置静态资源处理
    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/static/**")
                .addResourceLocations("/static/");
    }
}

Controller示例

package com.example.controller;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
@Controller
@RequestMapping("/users")
public class UserController {
    // 返回视图
    @GetMapping("/list")
    public String list() {
        return "userList";  // 对应 /WEB-INF/views/userList.jsp
    }
    // RESTful接口
    @GetMapping("/{id}")
    @ResponseBody
    public User getUser(@PathVariable Long id) {
        return userService.findById(id);
    }
    // 接收表单数据
    @PostMapping
    public String createUser(User user) {
        userService.save(user);
        return "redirect:/users/list";
    }
}

Spring Boot方式(最简捷)

依赖配置(pom.xml)

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.7.0</version>
</parent>
<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <!-- JSP支持(可选) -->
    <dependency>
        <groupId>org.apache.tomcat.embed</groupId>
        <artifactId>tomcat-embed-jasper</artifactId>
        <scope>provided</scope>
    </dependency>
</dependencies>

启动类

package com.example;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

application.yml配置

spring:
  mvc:
    view:
      prefix: /WEB-INF/views/
      suffix: .jsp
  resources:
    static-locations: classpath:/static/

整合关键要点

组件扫描配置

// 确保扫描到所有组件
@ComponentScan({
    "com.example.controller",
    "com.example.service", 
    "com.example.dao"
})

异常处理

@ControllerAdvice
public class GlobalExceptionHandler {
    @ExceptionHandler(value = Exception.class)
    public ModelAndView handleException(Exception e) {
        ModelAndView mv = new ModelAndView();
        mv.addObject("error", e.getMessage());
        mv.setViewName("error");
        return mv;
    }
}

拦截器配置

@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new LoginInterceptor())
                .addPathPatterns("/**")
                .excludePathPatterns("/login", "/static/**");
    }
}

CORS跨域配置

@Configuration
public class WebConfig implements WebMvcConfigurer {
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/api/**")
                .allowedOrigins("http://localhost:8080")
                .allowedMethods("GET", "POST", "PUT", "DELETE")
                .allowedHeaders("*");
    }
}

推荐整合方案

  1. 新项目:优先使用Spring Boot + 注解配置
  2. 旧项目改造:使用全注解方式,逐步替换XML配置
  3. 学习测试:传统XML配置便于理解底层原理

选择合适的整合方式取决于你的项目需求和技术栈,Spring Boot是目前最推荐的方式,因为它大大简化了配置工作。

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