Spring MVC的WebMvcConfigurerAdapter用法收集（零配置，无XML配置）

原理先不了解，只记录常用方法

用法：

@EnableWebMvc

开启MVC配置，相当于

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <mvc:annotation-driven/>

</beans>

Conversion and Formatting

配置convert和formatter的方法有两种，分别使用ConverterRegistry和FormatterRegistry 

使用注册工厂

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.convert.converter.Converter;
import org.springframework.core.convert.converter.ConverterRegistry;

import javax.annotation.PostConstruct;
import java.util.Arrays;
import java.util.List;

@Configuration
public class MyConverterRegistry {
    @Autowired
    private ConverterRegistry converterRegistry;

    @PostConstruct
    public void init() {
        converterRegistry.addConverter(new StringToListConvert());
    }

    private static  class StringToListConvert implements Converter<String, List<String>> {
        @Override
        public List<String> convert(String source) {
            if (source == null) {
                return Arrays.asList();
            } else {
                String[] split = source.split(",");
                return Arrays.asList(split);
            }
        }
    }
}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Configuration;
import org.springframework.format.Formatter;
import org.springframework.format.FormatterRegistry;

import javax.annotation.PostConstruct;
import java.text.ParseException;
import java.util.List;
import java.util.Locale;

@Configuration
public class MyFormatterRegistry {

    @Autowired
    private FormatterRegistry formatterRegistry;

    @PostConstruct
    public void init() {
        formatterRegistry.addFormatter(new StringDateFormatter());
    }


    public static class StringDateFormatter implements Formatter<List> {
        //解析接口，根据Locale信息解析字符串到T类型的对象；

        @Override
        public List parse(String text, Locale locale) throws ParseException {
            return null;
        }

        //格式化显示接口，将T类型的对象根据Locale信息以某种格式进行打印显示（即返回字符串形式）；
        @Override
        public String print(List object, Locale locale) {
            return "我是格式化的日期";
        }
    }
}

WebMvcConfigurerAdapter

import com.lf.web.convert.StringToListConvert;
import com.lf.web.formatter.StringDateFormatter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.format.FormatterRegistry;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ViewResolverRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@Configuration
@EnableWebMvc
@ComponentScan//组件扫描
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addFormatters(FormatterRegistry registry) {
        super.addFormatters(registry);
        registry.addFormatter(new StringDateFormatter());
        registry.addConverter(new StringToListConvert());
    }
}

使用XML配置

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc
        http://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <mvc:annotation-driven conversion-service="conversionService"/>

    <bean id="conversionService" class="org.springframework.format.support.FormattingConversionServiceFactoryBean">
        <property name="converters">
            <set>
                <bean class="com.web.convert.StringToListConvert"/>
            </set>
        </property>
        <property name="formatters">
            <set>
                <bean class="com.web.formatter.StringDateFormatter"/>
            </set>
        </property>
        <property name="formatterRegistrars">
            <set>
                <bean class="com.web.formatter.StringDateFormatter"/>
            </set>
        </property>
    </bean>

</beans> 

Interceptors

拦截器的实现

import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MyHandlerInterceptor extends HandlerInterceptorAdapter {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        System.out.println("===========HandlerInterceptor1 preHandle");
        return super.preHandle(request, response, handler);
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        super.postHandle(request, response, handler, modelAndView);
        System.out.println("===========HandlerInterceptor1 postHandle");
    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
        super.afterCompletion(request, response, handler, ex);
        System.out.println("===========HandlerInterceptor1 afterCompletion");
    }
}

XML配置

<bean id="handlerInterceptor1"   class="com.lf.web.MyHandlerInterceptor"/>  
<bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping">  
    <property name="interceptors">  
        <list>  
           <ref bean="handlerInterceptor1"/>  
           <ref bean="handlerInterceptor2"/>  
        </list>  
    </property>  
</bean> 

<mvc:interceptors>
    <bean class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor"/>
    <mvc:interceptor>
        <mvc:mapping path="/**"/>
        <mvc:exclude-mapping path="/admin/**"/>
        <bean class="org.springframework.web.servlet.theme.ThemeChangeInterceptor"/>
    </mvc:interceptor>
    <mvc:interceptor>
        <mvc:mapping path="/secure/*"/>
        <bean class="org.example.SecurityInterceptor"/>
    </mvc:interceptor>
</mvc:interceptors>

使用Java配置

import com.lf.web.convert.StringToListConvert;
import com.lf.web.formatter.StringDateFormatter;
import com.lf.web.interceptor.MyHandlerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.format.FormatterRegistry;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.config.annotation.*;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

@Configuration
@EnableWebMvc
@ComponentScan//组件扫描
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        super.addInterceptors(registry);
        registry.addInterceptor(new MyHandlerInterceptor()).addPathPatterns("/").excludePathPatterns("/admin");    
    }
}

ConfigureContentNegotiation

ContentNegotiatingViewResolver是ViewResolver使用所请求的媒体类型的一个实现(基于文件类型扩展，输出格式URL参数指定类型或接受报头)来选择一个合适的视图一个请求。ContentNegotiatingViewResolver本身并不解决视图，只不表示为其他的ViewResolver，您可以配置来处理特定的视图（XML，JSON，PDF，XLS，HTML，..）。

@Configuration
@EnableWebMvc
@ComponentScan//组件扫描
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
        configurer.mediaType("json", MediaType.APPLICATION_JSON);
    }
}

<mvc:annotation-driven content-negotiation-manager="contentNegotiationManager"/>

<bean id="contentNegotiationManager" class="org.springframework.web.accept.ContentNegotiationManagerFactoryBean">
    <property name="mediaTypes">
        <value>
            json=application/json
            xml=application/xml
        </value>
    </property>
</bean>

View

@Configuration
@EnableWebMvc
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        registry.addViewController("/").setViewName("home");
    }

}

<mvc:view-controller path="/" view-name="home"/>

View Resolvers

@Configuration
@EnableWebMvc
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void configureViewResolvers(ViewResolverRegistry registry) {
        registry.enableContentNegotiation(new MappingJackson2JsonView());
        registry.jsp();
    }

}

<mvc:view-resolvers>
    <mvc:content-negotiation>
        <mvc:default-views>
            <bean class="org.springframework.web.servlet.view.json.MappingJackson2JsonView"/>
        </mvc:default-views>
    </mvc:content-negotiation>
    <mvc:jsp/>
</mvc:view-resolvers>

Resources

@Configuration
@EnableWebMvc
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/resources/**").addResourceLocations("/public-resources/");
    }

}

<mvc:resources mapping="/resources/**" location="/public-resources/"/>

@Configuration
@EnableWebMvc
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
    }

}

<mvc:default-servlet-handler/>

@Configuration
@EnableWebMvc
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable("myCustomDefaultServlet");
    }

}

Path Matching

@Configuration
@EnableWebMvc
public class WebConfig extends WebMvcConfigurerAdapter {

    @Override
    public void configurePathMatch(PathMatchConfigurer configurer) {
        configurer
            .setUseSuffixPatternMatch(true)
            .setUseTrailingSlashMatch(false)
            .setUseRegisteredSuffixPatternMatch(true)
            .setPathMatcher(antPathMatcher())
            .setUrlPathHelper(urlPathHelper());
    }

    @Bean
    public UrlPathHelper urlPathHelper() {
        //...
    }

    @Bean
    public PathMatcher antPathMatcher() {
        //...
    }

}

Message Converters

@Configuration
@EnableWebMvc
public class WebConfiguration extends WebMvcConfigurerAdapter {

    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder()
                .indentOutput(true)
                .dateFormat(new SimpleDateFormat("yyyy-MM-dd"))
                .modulesToInstall(new ParameterNamesModule());
        converters.add(new MappingJackson2HttpMessageConverter(builder.build()));
        converters.add(new MappingJackson2XmlHttpMessageConverter(builder.xml().build()));
    }

}

以上示例代码：https://gitee.com/jim.zhan/SpringLearning

下面是基于零配置的项目示例：

1、创建一个动态Web项目（无需web.xml）

2、右键项目添加几个package: com.easyweb.config（保存项目配置）、com.easyweb.controller（保存Spring MVC Controller）

3、在com.easyweb.config新建一个类WebApplicationStartup，这个类实现WebApplicationInitializer接口，是项目的入口，作用类似于web.xml，具体代码如下：

import javax.servlet.MultipartConfigElement;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration.Dynamic;
 
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;
 
/**
 * 服务器启动入口类
 *
 * @author Administrator
 *
 */
public class WebApplicationStartup implements WebApplicationInitializer {
 
  private static final String SERVLET_NAME = Spring-mvc;
 
  private static final long MAX_FILE_UPLOAD_SIZE = 1024 * 1024 * 5; // 5 Mb
 
  private static final int FILE_SIZE_THRESHOLD = 1024 * 1024; // After 1Mb
 
  private static final long MAX_REQUEST_SIZE = -1L; // No request size limit
 
  /**
   * 服务器启动调用此方法，在这里可以做配置 作用与web.xml相同
   */
  @Override
  public void onStartup(ServletContext servletContext) throws ServletException {
    // 注册springMvc的servlet
    this.addServlet(servletContext);
    // 注册过滤器
    // servletContext.addFilter(arg0, arg1)
    // 注册监听器
    // servletContext.addListener(arg0);
  }
 
  /**
   * 注册Spring servlet
   *
   * @param servletContext
   */
  private void addServlet(ServletContext servletContext) {
    // 构建一个application context
    AnnotationConfigWebApplicationContext webContext = createWebContext(SpringMVC.class, ViewConfiguration.class);
    // 注册spring mvc 的 servlet
    Dynamic dynamic = servletContext.addServlet(SERVLET_NAME, new DispatcherServlet(webContext));
    // 添加springMVC 允许访问的Controller后缀
    dynamic.addMapping(*.html, *.ajax, *.css, *.js, *.gif, *.jpg, *.png);
    // 全部通过请用 “/”
    // dynamic.addMapping(/);
    dynamic.setLoadOnStartup(1);
    dynamic.setMultipartConfig(new MultipartConfigElement(null, MAX_FILE_UPLOAD_SIZE, MAX_REQUEST_SIZE, FILE_SIZE_THRESHOLD));
  }
 
  /**
   * 通过自定义的配置类来实例化一个Web Application Context
   *
   * @param annotatedClasses
   * @return
   */
  private AnnotationConfigWebApplicationContext createWebContext(Class<!--?-->... annotatedClasses) {
    AnnotationConfigWebApplicationContext webContext = new AnnotationConfigWebApplicationContext();
    webContext.register(annotatedClasses);
 
    return webContext;
  }
 
}

4、在com.easyweb.config下添加类SpringMVC继承WebMvcConfigurerAdapter，这个类的作用是进行SpringMVC的一些配置，代码如下：

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
 
@Configuration
@EnableWebMvc
//指明controller所在的包名
@ComponentScan(basePackages = {com.easyweb.controller})
public class SpringMVC extends WebMvcConfigurerAdapter {
 
  /**
   * 非必须
   */
  @Override
  public void configureDefaultServletHandling(final DefaultServletHandlerConfigurer configurer) {
    configurer.enable();
  }
 
  /**
   * 如果项目的一些资源文件放在/WEB-INF/resources/下面
   * 在浏览器访问的地址就是类似：https://host:port/projectName/WEB-INF/resources/xxx.css
   * 但是加了如下定义之后就可以这样访问：
   * https://host:port/projectName/resources/xxx.css
   * 非必须
   */
  @Override
  public void addResourceHandlers(final ResourceHandlerRegistry registry) {
    registry.addResourceHandler("/resources/**/*").addResourceLocations("/WEB-INF/resources/");
  }
}

5、添加View配置文件com.easyweb.config下新建类ViewConfiguration，里面可以根据自己的需要定义视图拦截器：

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.ViewResolver;
import org.springframework.web.servlet.view.JstlView;
import org.springframework.web.servlet.view.UrlBasedViewResolver;
import org.springframework.web.servlet.view.tiles2.TilesConfigurer;
import org.springframework.web.servlet.view.tiles2.TilesView;
 
@Configuration
public class ViewConfiguration {
 
    @Bean
    public ViewResolver urlBasedViewResolver() {
        UrlBasedViewResolver viewResolver;
        viewResolver = new UrlBasedViewResolver();
        viewResolver.setOrder(2);
        viewResolver.setPrefix(/WEB-INF/);
        viewResolver.setSuffix(.jsp);
        viewResolver.setViewClass(JstlView.class);
        // for debug envirment
        viewResolver.setCache(false);
        return viewResolver;
    }
    @Bean
    public ViewResolver tilesViewResolver() {
        UrlBasedViewResolver urlBasedViewResolver = new UrlBasedViewResolver();
        urlBasedViewResolver.setOrder(1);
        urlBasedViewResolver.setViewClass(TilesView.class);
        //urlBasedViewResolver.
        return urlBasedViewResolver;
    }
    @Bean
    public TilesConfigurer tilesConfigurer() {
        TilesConfigurer tilesConfigurer = new TilesConfigurer();
        tilesConfigurer.setDefinitions(new String[] { classpath:tiles.xml });
        return tilesConfigurer;
    }
} 

参考：

http://blog.csdn.net/L_Sail/article/details/71436392（以上大部分内容转自此篇文章）

https://www.2cto.com/kf/201508/432280.html

https://segmentfault.com/a/1190000004343063?_ea=575820（以上小部分内容转自此篇文章）

https://docs.spring.io/spring/docs/current/javadoc-api/org/springframework/web/servlet/config/annotation/WebMvcConfigurerAdapter.html（官方文档）