Java tutorial
/** * Copyright (C) 2015 Bonitasoft S.A. * Bonitasoft, 32 rue Gustave Eiffel - 38000 Grenoble * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 2.0 of the License, or * (at your option) any later version. * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package org.bonitasoft.web.designer.config; import java.io.IOException; import java.nio.charset.Charset; import java.util.Arrays; import java.util.List; import javax.inject.Inject; import com.fasterxml.jackson.databind.ObjectMapper; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.core.io.ResourceLoader; import org.springframework.http.MediaType; import org.springframework.http.converter.HttpMessageConverter; import org.springframework.http.converter.StringHttpMessageConverter; import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter; import org.springframework.web.multipart.support.StandardServletMultipartResolver; import org.springframework.web.servlet.config.annotation.DefaultServletHandlerConfigurer; 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.ViewControllerRegistry; import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter; import org.springframework.web.servlet.mvc.WebContentInterceptor; @Configuration @EnableWebMvc public class WebMvcConfiguration extends WebMvcConfigurerAdapter { private static final Logger logger = LoggerFactory.getLogger(WebMvcConfiguration.class); public final static String BACKEND_RESOURCES = "classpath:/META-INF/resources/"; public final static String FRONTEND_RESOURCES = "classpath:/static/"; public final static String WIDGETS_RESOURCES = "classpath:/widgets/"; private static final String[] CLASSPATH_RESOURCE_LOCATIONS = { BACKEND_RESOURCES, FRONTEND_RESOURCES }; @Autowired private ResourceLoader resourceLoader; /** * Jackson object mapper used to serialize or deserialize Json objects * * @see DesignerConfig#objectMapper() */ @Inject public ObjectMapper objectMapper; /** * To use multipart (based on Servlet 3.0) we need to mark the DispatcherServlet with a {@link javax.servlet.MultipartConfigElement} in programmatic Servlet * registration. Configuration settings such as maximum sizes or storage locations need to be applied at that Servlet registration level as Servlet 3.0 does * not allow for those settings to be done from the MultipartResolver. */ @Bean public StandardServletMultipartResolver multipartResolver() { return new StandardServletMultipartResolver(); } /** * This allows for mapping the DispatcherServlet to "/" (thus overriding the mapping of the containers default Servlet), while still allowing static resource * requests to be handled by the containers default Servlet. It configures a DefaultServletHttpRequestHandler with a URL mapping of "/**" and the lowest priority * relative to other URL mappings. */ @Override public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) { configurer.enable(); } /** * In Internet Explorer http requests are cached by default. It's a problem when we want to provide a REST API. This interceptor * adds headers in the responses to desactivate the cache. NB : static resources are cached but managed by the resource handlers * * @param registry */ @Override public void addInterceptors(InterceptorRegistry registry) { WebContentInterceptor interceptor = new WebContentInterceptor(); interceptor.setCacheSeconds(0); interceptor.setUseExpiresHeader(true); interceptor.setUseCacheControlHeader(true); interceptor.setUseCacheControlNoStore(true); registry.addInterceptor(interceptor); } /** * Add resources handler to help Spring to manage our static resources (from frontend and backend) */ @Override public void addResourceHandlers(ResourceHandlerRegistry registry) { if (!registry.hasMappingForPattern("/i18n/*")) { registry.addResourceHandler("/i18n/*").addResourceLocations("classpath:/i18n/"); } if (!registry.hasMappingForPattern("/widgets/**")) { registry.addResourceHandler("/widgets/**").addResourceLocations(WIDGETS_RESOURCES); } if (!registry.hasMappingForPattern("/**")) { registry.addResourceHandler("/**").addResourceLocations(CLASSPATH_RESOURCE_LOCATIONS); } } @Override public void addViewControllers(ViewControllerRegistry registry) { if (this.resourceLoader.getResource("classpath:/static/index.html").exists()) { // Use forward: prefix so that no view resolution is done try { logger.info("Adding welcome page: " + this.resourceLoader.getResource(FRONTEND_RESOURCES + "index.html").getURL()); registry.addViewController("/").setViewName("forward:/index.html"); } catch (IOException e) { logger.error("The home page index.html was not found", e); } } } /** * Spring MVC use a default objectMapper. Objects passed to and returned from the controllers are converted to and from HTTP messages by HttpMessageConverter * instances. We must use our {{@link #objectMapper}} because of the subtypes.... So we declare two message converters * <ul> * <li>StringHttpMessageConverter to format the String sent by HTTP like a JSON object representation</li> * <li>MappingJackson2HttpMessageConverter to use our {{@link #objectMapper}}</li> * </ul>To declare a JacksonHttpMessageConvet */ @Override public void configureMessageConverters(List<HttpMessageConverter<?>> converters) { //Add a converter for the String sent via HTTP StringHttpMessageConverter stringConverter = new StringHttpMessageConverter(Charset.forName("UTF-8")); stringConverter.setWriteAcceptCharset(false); // see SPR-7316 converters.add(stringConverter); //Use our custom Jackson serializer MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter = new MappingJackson2HttpMessageConverter( objectMapper); mappingJackson2HttpMessageConverter.setSupportedMediaTypes(supportedMediaTypes()); converters.add(mappingJackson2HttpMessageConverter); } public static List<MediaType> supportedMediaTypes() { return Arrays.asList(new MediaType("application", "json", Charset.forName("UTF-8")), new MediaType("text", "plain", Charset.forName("UTF-8"))); } }