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，来开启对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，本章若不做特别说明，则关于配置的相关内容都在MyMvcConfig里编写。
4.1.1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
同上，我们在src/main/resources下建立assets/js目录，并复制一个jquery.js放置在此目录下，如图
配置代码：
package com.wisely.highlight_springmvc4;
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;
import com.wisely.highlight_springmvc4.interceptor.DemoInterceptor;
@Configuration
@EnableWebMvc //开启SpringMVC支持，若无此名，重写WebMvcConfigurerAdapter方法无效。
@ComponentScan("com.wisely.highlight_springmvc4")
public class MyMvcConfig extends WebMvcConfigurerAdapter { //继承WebMvcConfigurerAdapter类，重写其方法可对Spring MVC进行配置。
@Bean
public InternalResourceViewResolver viewResolver(){
InternalResourceViewResolver viewResolver = new InternalResourceViewResolver();
viewResolver.setPrefix("/WEB-INF/classes/views/");
viewResolver.setSuffix(".jsp");
viewResolver.setViewClass(JstlView.class);
return viewResolver;
}
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
registry.addResourceHandler("/assets/**").addResourceLocations("classpath:/assets/"); //addResourceLocations指的是文件放置的目录，addResourceHandler指的是对外暴露的访问路径。
}
}4.4.2拦截器配置
拦截器（Interceptor实现对每一个请求处理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HanlderIntercepttor接口或者继承HandlerInterceptorAdapter类来实现自定义拦截器。
通过重写WebMvcConfigurerAdapter的addInterceptors方法来注册自定义的拦截器，本节演示一个简单的拦截器的开发和配置，业务含义为计算每一次请求的处理时间。
示例
（1）示例拦截器。
package com.wisely.highlight_springmvc4.interceptor;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
public class DemoInterceptor extends HandlerInterceptorAdapter { //通过继承实现自定义拦截器
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
throws Exception { //重写preHandle方法，在请求发生前执行
long startTime = System.currentTimeMillis();
request.setAttribute("startTime", startTime);
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
ModelAndView modelAndView) throws Exception { //重写postHandle方法，在请求完成后执行
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);
}
}（2）配置。
@Bean //配置拦截器的Bean
public DemoInterceptor demoInterceptor(){
return new DemoInterceptor();
}
@Override
public void addInterceptors(InterceptorRegistry registry) {
registry.addInterceptor(demoInterceptor()); //重写方法，注册拦截器（3）运行。在浏览器访问任意路径，如http//localhost:8080/highlight_springnvc4/index，查看控制台如图
4.4.3 @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@Controller的类的方法可使用@ExceptionHandler、@InitBinder、@ModelAttribute注解到方法@ExceptionHandler：用于全局处理控制器里的异常。
@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都能获得在此处设置的键值对。
本节将演示使用@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 com.wisely.highlight_springmvc4.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;
@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
public class ExceptionHandlerAdvice {
@ExceptionHandler(value = Exception.class) //@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，在此处我们可以看出我们拦截所有的Exception
public ModelAndView exception(Exception exception,WebRequest request){
ModelAndView modelAndView = new ModelAndView("error"); //error页面
modelAndView.addObject("errorMessage",exception.getMessage());
return modelAndView;
}
@ModelAttribute //此处使用@ModelAttribute注解将键值对添加到全局，所有注解的@RequestMapping的方法可获得此键值对。
public void addAttributes(Model model){
model.addAttribute("msg", "额外信息");
}
@InitBinder //定制WebDataBinder
public void initBinder(WebDataBinder webDataBinder){
webDataBinder.setDisallowedFields("id"); //此处演示忽略request参数的id,更多关于WebDataBinder的配置，请参考WebDataBinder的API文档。
}
}（2）演示控制器。
package com.wisely.highlight_springmvc4.web.ch4_4;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import com.wisely.highlight_springmvc4.domain.DemoObj;
@Controller
public class AdviceController {
@RequestMapping("/advice")
public String getSomething(@ModelAttribute("msg") String msg,DemoObj obj) throws IllegalAccessException{
throw new IllegalAccessException("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 uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>@ControllerAdvice Demo</title>
</head>
<body>
${errorMessage}
</body>
</html>（4）运行。
访问http://localhost:8080/highlight_springmvc4/advice?id=1&name=xx
调试查看DemoObj，id被过滤掉了，且获得了@ModelAttribute的msg信息，如图
页面效果如图
4.4.4其它配置
1.快捷的ViewController
在4.2.2节我们配置页面转向的时候使用的代码如下：
@RequestMapping("/index")
public String hello(){
return "index";此处无任何业务处理，只是简单的页面转向，写了至少三行有效代码;在实际开发上会涉及大量这样的页面转向，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：
@Override
public void addViewControllers(ViewControllerRegistry registry) {
// TODO Auto-generated method stub
registry.addViewController("/index").setViewName("/index");
}这样实现的代码更简洁，管理更集中。
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/highlight_springmvc4/anno/pathvar/xx.yy,此时“.”
后面的yy被忽略，如图
通过重写configurePathMatch方法可以不忽略"."后面的参数，代码如下：
@Override
public void configurePathMatch(PathMatchConfigurer configurer) {
// TODO Auto-generated method stub
configurer.setUseSuffixPatternMatch(false);
}这时再访问http://localhost:8080/highlight_springmvc4/anno/pathvar/xx.yy，就可以接近“.”后面的yy了，如图
3.更多配置
更多配置请看WebMvcConfigurerAdapter类的API。其因是WebMvcConfigurer接口实现，所以WebMvcConfigurer的API内的方法也可以用来配置MVC。下面我们列出了WebMvcConfigurerAdapter和WebMvcConfigurer的源码。
4.WebMvcConfigurerAdapter
public abstract class WebMvcConfigurerAdapter implements WebMvcConfigurer {
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void addFormatters(FormatterRegistry registry) {
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
}
/**
* {@inheritDoc}
* <p>This implementation returns {@code null}
*/
@Override
public Validator getValidator() {
return null;
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void configureAsyncSupport(AsyncSupportConfigurer configurer) {
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void configurePathMatch(PathMatchConfigurer configurer) {
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers) {
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers) {
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public MessageCodesResolver getMessageCodesResolver() {
return null;
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void addInterceptors(InterceptorRegistry registry) {
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void addViewControllers(ViewControllerRegistry registry) {
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void configureViewResolvers(ViewResolverRegistry registry) {
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
}
/**
* {@inheritDoc}
* <p>This implementation is empty.
*/
@Override
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
}
}5.WebMvcConfigurer
public interface WebMvcConfigurer {
/**
* Add {@link Converter}s and {@link Formatter}s in addition to the ones
* registered by default.
*/
void addFormatters(FormatterRegistry registry);
/**
* Configure the {@link HttpMessageConverter}s to use for reading or writing
* to the body of the request or response. If no converters are added, a
* default list of converters is registered.
* <p><strong>Note</strong> that adding converters to the list, turns off
* default converter registration. To simply add a converter without impacting
* default registration, consider using the method
* {@link #extendMessageConverters(java.util.List)} instead.
* @param converters initially an empty list of converters
*/
void configureMessageConverters(List<HttpMessageConverter<?>> converters);
/**
* A hook for extending or modifying the list of converters after it has been
* configured. This may be useful for example to allow default converters to
* be registered and then insert a custom converter through this method.
* @param converters the list of configured converters to extend.
* @since 4.1.3
*/
void extendMessageConverters(List<HttpMessageConverter<?>> converters);
/**
* Provide a custom {@link Validator} instead of the one created by default.
* The default implementation, assuming JSR-303 is on the classpath, is:
* {@link org.springframework.validation.beanvalidation.OptionalValidatorFactoryBean}.
* Leave the return value as {@code null} to keep the default.
*/
Validator getValidator();
/**
* Configure content negotiation options.
*/
void configureContentNegotiation(ContentNegotiationConfigurer configurer);
/**
* Configure asynchronous request handling options.
*/
void configureAsyncSupport(AsyncSupportConfigurer configurer);
/**
* Helps with configuring HandlerMappings path matching options such as trailing slash match,
* suffix registration, path matcher and path helper.
* Configured path matcher and path helper instances are shared for:
* <ul>
* <li>RequestMappings</li>
* <li>ViewControllerMappings</li>
* <li>ResourcesMappings</li>
* </ul>
* @since 4.0.3
*/
void configurePathMatch(PathMatchConfigurer configurer);
/**
* Add resolvers to support custom controller method argument types.
* <p>This does not override the built-in support for resolving handler
* method arguments. To customize the built-in support for argument
* resolution, configure {@link RequestMappingHandlerAdapter} directly.
* @param argumentResolvers initially an empty list
*/
void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers);
/**
* Add handlers to support custom controller method return value types.
* <p>Using this option does not override the built-in support for handling
* return values. To customize the built-in support for handling return
* values, configure RequestMappingHandlerAdapter directly.
* @param returnValueHandlers initially an empty list
*/
void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers);
/**
* Configure the {@link HandlerExceptionResolver}s to handle unresolved
* controller exceptions. If no resolvers are added to the list, default
* exception resolvers are added instead.
* @param exceptionResolvers initially an empty list
*/
void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers);
/**
* Add Spring MVC lifecycle interceptors for pre- and post-processing of
* controller method invocations. Interceptors can be registered to apply
* to all requests or be limited to a subset of URL patterns.
* <p><strong>Note</strong> that interceptors registered here only apply to
* controllers and not to resource handler requests. To intercept requests for
* static resources either declare a
* {@link org.springframework.web.servlet.handler.MappedInterceptor MappedInterceptor}
* bean or switch to advanced configuration mode by extending
* {@link org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport
* WebMvcConfigurationSupport} and then override {@code resourceHandlerMapping}.
*/
void addInterceptors(InterceptorRegistry registry);
/**
* Provide a custom {@link MessageCodesResolver} for building message codes
* from data binding and validation error codes. Leave the return value as
* {@code null} to keep the default.
*/
MessageCodesResolver getMessageCodesResolver();
/**
* Configure simple automated controllers pre-configured with the response
* status code and/or a view to render the response body. This is useful in
* cases where there is no need for custom controller logic -- e.g. render a
* home page, perform simple site URL redirects, return a 404 status with
* HTML content, a 204 with no content, and more.
*/
void addViewControllers(ViewControllerRegistry registry);
/**
* Configure view resolvers to translate String-based view names returned from
* controllers into concrete {@link org.springframework.web.servlet.View}
* implementations to perform rendering with.
*/
void configureViewResolvers(ViewResolverRegistry registry);
/**
* Add handlers to serve static resources such as images, js, and, css
* files from specific locations under web application root, the classpath,
* and others.
*/
void addResourceHandlers(ResourceHandlerRegistry registry);
/**
* Configure a handler to delegate unhandled requests by forwarding to the
* Servlet container's "default" servlet. A common use case for this is when
* the {@link DispatcherServlet} is mapped to "/" thus overriding the
* Servlet container's default handling of static resources.
*/
void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer);
}
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