SpringBoot8-Spring MVC-Spring MVC基本配置
Spring MVC的定制配置需要我们的配置类继承一个WebMvcConfigurerAdapter类,并在此类使用@EnableWebMvc注解,并开启对Spring MVC的配置支持,这样我们就可以重写这个类的方法,完成我们的常用配置。
我们将前面的MyMvcConfig配置类继承WebMvcConfigurerAdapter。下面没有特别说明,关于配置的相关内容都在MyMvcConfig里编写。
一:静态资源映射
程序的静态文件(js,css,图片)等需要直接访问,这时我们可以在配置里重写addResourceHandlers方法来实现。
示例:
1,添加静态资源
我们在src/main/resource建立assets/js目录,并复制一个jquery的js文件放置在此目录,如下:
配置代码如下:
- package jack.springmvc.config;
- import org.springframework.context.annotation.Bean;
- import org.springframework.context.annotation.ComponentScan;
- import org.springframework.context.annotation.Configuration;
- import org.springframework.web.servlet.config.annotation.EnableWebMvc;
- import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
- import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
- import org.springframework.web.servlet.view.InternalResourceViewResolver;
- import org.springframework.web.servlet.view.JstlView;
- /**
- * Created by jack on 2017/7/16.
- */
- @Configuration
- @EnableWebMvc //开启Spring MVC支持,若无此句,重写WebMvcConfigurerAdapter方法无效
- @ComponentScan("jack.springmvc")
- //继承WebMvcConfigurerAdapter类,重写其方法可对Spring MVC进行配置
- public class MyMvcConfig extends WebMvcConfigurerAdapter{
- @Bean
- public InternalResourceViewResolver viewResolver(){
- InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
- //viewResolver.setPrefix("/WEB-INF/classes/views/");
- viewResolver.setPrefix("/WEB-INF/classes/views/");
- viewResolver.setSuffix(".jsp");
- viewResolver.setViewClass(JstlView.class);
- return viewResolver;
- }
- @Override
- public void addResourceHandlers(ResourceHandlerRegistry registry) {
- //super.addResourceHandlers(registry);
- //addResourceLocations指的是文件放置的目录,addResourceHandler指的是对外暴露的访问路径
- registry.addResourceHandler("/assets/**").addResourceLocations("classpath:/assets/");
- }
- }
二:拦截器配置
拦截器(Interceptor)实现对每一个请求前后进行相关的业务处理,类似于Servlet的Filter。 可让普通的Bean实现HanlderInterceptor接口或者继承HandlerInterceptorAdapter类来实现自定义拦截器。
通过重写WebMvcConfigurerAdapter的addInterceptors方法来注册自定义拦截器,下面演示一个简单拦截器的开发和配置,业务含义为计算每一次的处理时间。
示例:
编写拦截器代码:
- package jack.springmvc.interceptor;
- import org.springframework.web.servlet.ModelAndView;
- import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- /**
- * Created by jack on 2017/7/24.
- */
- //继承HandlerInterceptorAdapter类来实现自定义拦截器
- public class DemoInterceptor extends HandlerInterceptorAdapter{
- /**
- * 重写preHandle方法,在请求发生之前执行
- * @param request
- * @param response
- * @param handler
- * @return
- * @throws Exception
- */
- @Override
- public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
- //return super.preHandle(request, response, handler);
- long startTime = System.currentTimeMillis();
- request.setAttribute("startTime",startTime);
- return true;
- }
- /**
- * 重写postHandle方法,在请求完成之后执行
- * @param request
- * @param response
- * @param handler
- * @param modelAndView
- * @throws Exception
- */
- @Override
- public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
- //super.postHandle(request, response, handler, modelAndView);
- long startTime = (long) request.getAttribute("startTime");
- request.removeAttribute("startTime");
- long endTime = System.currentTimeMillis();
- System.out.println("本次请求处理时间为:"+new Long(endTime-startTime)+"ms");
- request.setAttribute("handlingTime",endTime-startTime);
- }
- }
配置拦截器,配置拦截器的Bean,重写addInterceptors,注册拦截器,代码如下:
- package jack.springmvc.config;
- import jack.springmvc.interceptor.DemoInterceptor;
- import org.springframework.context.annotation.Bean;
- import org.springframework.context.annotation.ComponentScan;
- import org.springframework.context.annotation.Configuration;
- import org.springframework.web.servlet.config.annotation.EnableWebMvc;
- import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
- import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
- import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
- import org.springframework.web.servlet.view.InternalResourceViewResolver;
- import org.springframework.web.servlet.view.JstlView;
- /**
- * Created by jack on 2017/7/16.
- */
- @Configuration
- @EnableWebMvc //开启Spring MVC支持,若无此句,重写WebMvcConfigurerAdapter方法无效
- @ComponentScan("jack.springmvc")
- //继承WebMvcConfigurerAdapter类,重写其方法可对Spring MVC进行配置
- public class MyMvcConfig extends WebMvcConfigurerAdapter{
- /**
- * 配置拦截器的Bean
- * @return
- */
- @Bean
- public DemoInterceptor demoInterceptor(){
- return new DemoInterceptor();
- }
- /**
- * c重写addInterceptors方法,注册拦截器
- * @param registry
- */
- @Override
- public void addInterceptors(InterceptorRegistry registry) {
- //super.addInterceptors(registry);
- registry.addInterceptor(demoInterceptor());
- }
- @Bean
- public InternalResourceViewResolver viewResolver(){
- InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
- //viewResolver.setPrefix("/WEB-INF/classes/views/");
- viewResolver.setPrefix("/WEB-INF/classes/views/");
- viewResolver.setSuffix(".jsp");
- viewResolver.setViewClass(JstlView.class);
- return viewResolver;
- }
- @Override
- public void addResourceHandlers(ResourceHandlerRegistry registry) {
- //super.addResourceHandlers(registry);
- //addResourceLocations指的是文件放置的目录,addResourceHandler指的是对外暴露的访问路径
- registry.addResourceHandler("/assets/**").addResourceLocations("classpath:/assets/");
- }
- }
在浏览器输入:http://localhost:8080/index
输出如下:
三:@ControllerAdvice
通过@ControllerAdvice,我们可以将对于控制器的全局配置放置在同一个位置,注解了 @ControllerAdvice的类的方法可使用@ExceptionHandler,@InitBinder,@ModelAttribute注解到方法上,这对所有注解了@RequestMapping的控制器内的方法有效。 @ExceptionHandler:用于全局处理控制器的异常
@InitBinder:用来设置WebDataBinder,WebDataBinder用来自动绑定前台请求参数到Model中。
@ModelAttribute:@ModelAttribute本来的作用是绑定键值对到Model里,此处是让全局的@RequestMapping都能获得此处设置的键值对。
下面演示使用@ExceptionHandler处理全局异常,更人性化的将异常输出给用户。
示例:
1)定制ControllerAdvice
- package jack.springmvc.advice;
- import org.springframework.ui.Model;
- import org.springframework.web.bind.WebDataBinder;
- import org.springframework.web.bind.annotation.ControllerAdvice;
- import org.springframework.web.bind.annotation.ExceptionHandler;
- import org.springframework.web.bind.annotation.InitBinder;
- import org.springframework.web.bind.annotation.ModelAttribute;
- import org.springframework.web.context.request.WebRequest;
- import org.springframework.web.servlet.ModelAndView;
- /**
- * Created by jack on 2017/7/24.
- */
- //@ControllerAdvice声明一个控制器建言,@ControllerAdvice组合了@Component注解,所以自动注册为Spring的bean
- @ControllerAdvice
- public class ExceptionHandlerAdvice {
- /**
- * @ExceptionHandler在此处定义全局处理,通过@ExceptionHandler的value属性可过滤拦截的条件,
- * 再此我们可以看出我们拦截所有的Exception
- * @param exception
- * @param request
- * @return
- */
- @ExceptionHandler(value = Exception.class)
- public ModelAndView exception(Exception exception, WebRequest request){
- ModelAndView modelAndView = new ModelAndView("error");//error页面
- modelAndView.addObject("errorMessage",exception.getMessage());
- return modelAndView;
- }
- /**
- * 此处使用@ModelAttribute注解将键值对添加到全局,所有注解了@RequestMapping的方法可获得此键值对
- * @param model
- */
- @ModelAttribute
- public void addAttributes(Model model){
- model.addAttribute("msg", "额外信息");
- }
- /**
- * 通过@InitBinder注解定制WebDataBinder
- * @param webDataBinder
- */
- @InitBinder
- public void initBinder(WebDataBinder webDataBinder){
- //此处演示忽略request参数的id
- webDataBinder.setDisallowedFields("id");
- }
- }
2)演示控制器
- package jack.springmvc.controller;
- import jack.springmvc.domain.DemoObj;
- import org.springframework.stereotype.Controller;
- import org.springframework.web.bind.annotation.ModelAttribute;
- import org.springframework.web.bind.annotation.RequestMapping;
- /**
- * Created by jack on 2017/7/24.
- */
- @Controller
- public class AdviceController {
- @RequestMapping("/advice")
- public String getSomething(@ModelAttribute("msg") String msg, DemoObj obj){
- throw new IllegalArgumentException("非常抱歉,参数有误/" + "来自@ModelAttribute:" + msg);
- }
- }
3)异常展示页面
在src/main/resources/views下,新建error.jsp,内容如下:
- <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
- <%@ page contentType="text/html;charset=UTF-8" language="java" pageEncoding="UTF-8" %>
- <html>
- <head>
- <meta http-equiv="CONTENT-TYPE" content="text/html; charset=UTF-8" >
- <title>@ControllerAdvice Demo</title>
- </head>
- <body>
- <pre>
- ${errorMessage}
- </pre>
- </body>
- </html>
4)运行
在浏览器输入:http://localhost:8080/advice?id=1&name=xx,页面显示如下所示:
其中DemoObj的id被过滤掉了。且获得了@ModelAttribute的msg信息
四:其他配置
1,快捷的ViewController 在前面我们配置页面转向的时候使用了下面的代码:
- @RequestMapping(value = "/index")
- public String hello(){
- //通过MyMvcConfig里面的配置,通过ViewResolver的Bean配置,返回值为index,
- // 说明我们的页面存放的路径为/classes/views/index.jsp
- return "index";
- }
此处无任何业务处理,只是简单的页面转向,写了至少三行代码,在实际开发中会涉及大量的这样页面转向,若都这样写会很麻烦,我们可以通过在配置中重写addViewControllers来简化配置:
- package jack.springmvc.config;
- import jack.springmvc.interceptor.DemoInterceptor;
- import org.springframework.context.annotation.Bean;
- import org.springframework.context.annotation.ComponentScan;
- import org.springframework.context.annotation.Configuration;
- import org.springframework.web.servlet.config.annotation.*;
- import org.springframework.web.servlet.view.InternalResourceViewResolver;
- import org.springframework.web.servlet.view.JstlView;
- /**
- * Created by jack on 2017/7/16.
- */
- @Configuration
- @EnableWebMvc //开启Spring MVC支持,若无此句,重写WebMvcConfigurerAdapter方法无效
- @ComponentScan("jack.springmvc")
- //继承WebMvcConfigurerAdapter类,重写其方法可对Spring MVC进行配置
- public class MyMvcConfig extends WebMvcConfigurerAdapter{
- /**
- * 配置拦截器的Bean
- * @return
- */
- @Bean
- public DemoInterceptor demoInterceptor(){
- return new DemoInterceptor();
- }
- /**
- * c重写addInterceptors方法,注册拦截器
- * @param registry
- */
- @Override
- public void addInterceptors(InterceptorRegistry registry) {
- //super.addInterceptors(registry);
- registry.addInterceptor(demoInterceptor());
- }
- @Bean
- public InternalResourceViewResolver viewResolver(){
- InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
- //viewResolver.setPrefix("/WEB-INF/classes/views/");
- viewResolver.setPrefix("/WEB-INF/classes/views/");
- viewResolver.setSuffix(".jsp");
- viewResolver.setViewClass(JstlView.class);
- return viewResolver;
- }
- @Override
- public void addResourceHandlers(ResourceHandlerRegistry registry) {
- //super.addResourceHandlers(registry);
- //addResourceLocations指的是文件放置的目录,addResourceHandler指的是对外暴露的访问路径
- registry.addResourceHandler("/assets/**").addResourceLocations("classpath:/assets/");
- }
- /**
- * 统一处理没啥业务逻辑处理的controller请求,实现代码的简洁
- * @param registry
- */
- @Override
- public void addViewControllers(ViewControllerRegistry registry) {
- //super.addViewControllers(registry);
- registry.addViewController("/index").setViewName("/index");
- }
- }
注释掉之前处理/index的controller,重启服务器,输入http://localhost:8080/index进行访问,发现和之前是一样的结果。把没有业务的controller统一进行处理,代码根据简洁,管理更加集中了。
2,路径匹配参数配置
在spring mvc中,路径参数如果带“.”的话,“.”后面的值将被忽略,例如访问:http://localhost:8080/anno/pathvar/xx.yy,此时“.”后面的yy被忽略了,如下所示:
通过重写configurePathMatch方法可忽略"."后面的参数,代码如下:
- @Override
- public void configurePathMatch(PathMatchConfigurer configurer) {
- //super.configurePathMatch(configurer);
- configurer.setUseSuffixPatternMatch(false);
- }
目前spring mvc配置的完整代码如下:
- package jack.springmvc.config;
- import jack.springmvc.interceptor.DemoInterceptor;
- import org.springframework.context.annotation.Bean;
- import org.springframework.context.annotation.ComponentScan;
- import org.springframework.context.annotation.Configuration;
- import org.springframework.web.servlet.config.annotation.*;
- import org.springframework.web.servlet.view.InternalResourceViewResolver;
- import org.springframework.web.servlet.view.JstlView;
- /**
- * Created by jack on 2017/7/16.
- */
- @Configuration
- @EnableWebMvc //开启Spring MVC支持,若无此句,重写WebMvcConfigurerAdapter方法无效
- @ComponentScan("jack.springmvc")
- //继承WebMvcConfigurerAdapter类,重写其方法可对Spring MVC进行配置
- public class MyMvcConfig extends WebMvcConfigurerAdapter{
- /**
- * 配置拦截器的Bean
- * @return
- */
- @Bean
- public DemoInterceptor demoInterceptor(){
- return new DemoInterceptor();
- }
- /**
- * c重写addInterceptors方法,注册拦截器
- * @param registry
- */
- @Override
- public void addInterceptors(InterceptorRegistry registry) {
- //super.addInterceptors(registry);
- registry.addInterceptor(demoInterceptor());
- }
- @Bean
- public InternalResourceViewResolver viewResolver(){
- InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
- //viewResolver.setPrefix("/WEB-INF/classes/views/");
- viewResolver.setPrefix("/WEB-INF/classes/views/");
- viewResolver.setSuffix(".jsp");
- viewResolver.setViewClass(JstlView.class);
- return viewResolver;
- }
- @Override
- public void addResourceHandlers(ResourceHandlerRegistry registry) {
- //super.addResourceHandlers(registry);
- //addResourceLocations指的是文件放置的目录,addResourceHandler指的是对外暴露的访问路径
- registry.addResourceHandler("/assets/**").addResourceLocations("classpath:/assets/");
- }
- /**
- * 统一处理没啥业务逻辑处理的controller请求,实现代码的简洁
- * @param registry
- */
- @Override
- public void addViewControllers(ViewControllerRegistry registry) {
- //super.addViewControllers(registry);
- registry.addViewController("/index").setViewName("/index");
- }
- @Override
- public void configurePathMatch(PathMatchConfigurer configurer) {
- //super.configurePathMatch(configurer);
- configurer.setUseSuffixPatternMatch(false);
- }
- }
重启tomcat,在访问http://localhost:8080/anno/pathvar/xx.yy,就可以接受"."后面的yy了,如下:
3,更多配置
更多配置可以查看WebMvcConfigurerAdapter类的api。因其是WebMvcConfigurer接口的实现,所以WebMvcConfigurer的api内的也可以用来MVC。下面看看WebMvcConfigurerAdapter和WebMvcConfigurer的源码。
WebMvcConfigurerAdapter:
- //
- // Source code recreated from a .class file by IntelliJ IDEA
- // (powered by Fernflower decompiler)
- //
- package org.springframework.web.servlet.config.annotation;
- import java.util.List;
- import org.springframework.format.FormatterRegistry;
- import org.springframework.http.converter.HttpMessageConverter;
- import org.springframework.validation.MessageCodesResolver;
- import org.springframework.validation.Validator;
- import org.springframework.web.method.support.HandlerMethodArgumentResolver;
- import org.springframework.web.method.support.HandlerMethodReturnValueHandler;
- import org.springframework.web.servlet.HandlerExceptionResolver;
- import org.springframework.web.servlet.config.annotation.AsyncSupportConfigurer;
- import org.springframework.web.servlet.config.annotation.ContentNegotiationConfigurer;
- import org.springframework.web.servlet.config.annotation.CorsRegistry;
- import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
- import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
- import org.springframework.web.servlet.config.annotation.PathMatchConfigurer;
- import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
- import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
- import org.springframework.web.servlet.config.annotation.ViewResolverRegistry;
- import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
- public abstract class WebMvcConfigurerAdapter implements WebMvcConfigurer {
- public WebMvcConfigurerAdapter() {
- }
- public void configurePathMatch(PathMatchConfigurer configurer) {
- }
- public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
- }
- public void configureAsyncSupport(AsyncSupportConfigurer configurer) {
- }
- public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
- }
- public void addFormatters(FormatterRegistry registry) {
- }
- public void addInterceptors(InterceptorRegistry registry) {
- }
- public void addResourceHandlers(ResourceHandlerRegistry registry) {
- }
- public void addCorsMappings(CorsRegistry registry) {
- }
- public void addViewControllers(ViewControllerRegistry registry) {
- }
- public void configureViewResolvers(ViewResolverRegistry registry) {
- }
- public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
- }
- public void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers) {
- }
- public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
- }
- public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
- }
- public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers) {
- }
- public void extendHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers) {
- }
- public Validator getValidator() {
- return null;
- }
- public MessageCodesResolver getMessageCodesResolver() {
- return null;
- }
- }
WebMvcConfigurer:
- //
- // Source code recreated from a .class file by IntelliJ IDEA
- // (powered by Fernflower decompiler)
- //
- package org.springframework.web.servlet.config.annotation;
- import java.util.List;
- import org.springframework.format.FormatterRegistry;
- import org.springframework.http.converter.HttpMessageConverter;
- import org.springframework.validation.MessageCodesResolver;
- import org.springframework.validation.Validator;
- import org.springframework.web.method.support.HandlerMethodArgumentResolver;
- import org.springframework.web.method.support.HandlerMethodReturnValueHandler;
- import org.springframework.web.servlet.HandlerExceptionResolver;
- import org.springframework.web.servlet.config.annotation.AsyncSupportConfigurer;
- import org.springframework.web.servlet.config.annotation.ContentNegotiationConfigurer;
- import org.springframework.web.servlet.config.annotation.CorsRegistry;
- import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
- import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
- import org.springframework.web.servlet.config.annotation.PathMatchConfigurer;
- import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
- import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
- import org.springframework.web.servlet.config.annotation.ViewResolverRegistry;
- public interface WebMvcConfigurer {
- void configurePathMatch(PathMatchConfigurer var1);
- void configureContentNegotiation(ContentNegotiationConfigurer var1);
- void configureAsyncSupport(AsyncSupportConfigurer var1);
- void configureDefaultServletHandling(DefaultServletHandlerConfigurer var1);
- void addFormatters(FormatterRegistry var1);
- void addInterceptors(InterceptorRegistry var1);
- void addResourceHandlers(ResourceHandlerRegistry var1);
- void addCorsMappings(CorsRegistry var1);
- void addViewControllers(ViewControllerRegistry var1);
- void configureViewResolvers(ViewResolverRegistry var1);
- void addArgumentResolvers(List<HandlerMethodArgumentResolver> var1);
- void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> var1);
- void configureMessageConverters(List<HttpMessageConverter<?>> var1);
- void extendMessageConverters(List<HttpMessageConverter<?>> var1);
- void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> var1);
- void extendHandlerExceptionResolvers(List<HandlerExceptionResolver> var1);
- Validator getValidator();
- MessageCodesResolver getMessageCodesResolver();
- }