org.shaigor.rest.retro.config.WebAppInitializer.java Source code

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Here is the source code for org.shaigor.rest.retro.config.WebAppInitializer.java

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/**
 * Copyright 2014 the original author or authors.
 * 
 * This file is part of Retro-fitting Security into REST web services sample (the sample).
 * The sample is part of the talk presented at Java One 2014 
 *    https://oracleus.activeevents.com/2014/connect/sessionDetail.ww?SESSION_ID=1765&tclass=popup
 * 
 * The sample is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * The sample 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 Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with the sample.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.shaigor.rest.retro.config;

import java.util.Set;

import javax.servlet.ServletContext;
import javax.servlet.ServletRegistration;

import org.shaigor.rest.retro.service.impl.WordsSereviceConfig;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ContextLoaderListener;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;

/**
 * Spring alternative to web.xml
 * 
 * @author Irena Shaigorodsky
 */
public class WebAppInitializer implements WebApplicationInitializer {

    private static Logger LOG = LoggerFactory.getLogger(WebAppInitializer.class);

    @Override
    public void onStartup(ServletContext servletContext) {
        WebApplicationContext rootContext = createRootContext(servletContext);

        configureSpringMvc(servletContext, rootContext);
    }

    /**
     * Creates web application context 
     * @param servletContext to be used during creation and registration
     * @return web application context for the application
     */
    private WebApplicationContext createRootContext(ServletContext servletContext) {
        AnnotationConfigWebApplicationContext rootContext = new AnnotationConfigWebApplicationContext();
        rootContext.getEnvironment().setActiveProfiles("prod");
        Class<?>[] annotatedClasseses = configurations2Register();
        if (annotatedClasseses != null && annotatedClasseses.length > 0) {
            rootContext.register(annotatedClasseses);
        }
        rootContext.refresh();

        servletContext.addListener(new ContextLoaderListener(rootContext));
        servletContext.setInitParameter("defaultHtmlEscape", "true");

        return rootContext;
    }

    /**
     * Added for an ability to override with additional Spring configurations to be register
     * in the sample 
     * @return additional configurations to be register
     */
    protected Class<?>[] configurations2Register() {
        return null;
    }

    /**
     * Registers dispatcher servlet that will make MVC tick
     * @param servletContext to be used during creation and registration
     * @param rootContext web application context to be used during creation and registration
     */
    private void configureSpringMvc(ServletContext servletContext, WebApplicationContext rootContext) {
        AnnotationConfigWebApplicationContext mvcContext = new AnnotationConfigWebApplicationContext();
        mvcContext.register(WordsSereviceConfig.class, InsecureWebMvcConfigurer.class);

        mvcContext.setParent(rootContext);

        ServletRegistration.Dynamic appServlet = servletContext.addServlet("webservice",
                new DispatcherServlet(mvcContext));
        appServlet.setLoadOnStartup(1);
        Set<String> mappingConflicts = appServlet.addMapping("/");

        if (!mappingConflicts.isEmpty()) {
            for (String s : mappingConflicts) {
                LOG.error("Mapping conflict: " + s);
            }
            throw new IllegalStateException("'webservice' cannot be mapped to '/'");
        }
    }
}