org.usergrid.rest.SwaggerServlet.java Source code

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Here is the source code for org.usergrid.rest.SwaggerServlet.java

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/*******************************************************************************
 * Copyright 2012 Apigee Corporation
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/
package org.usergrid.rest;

import static org.apache.commons.lang.StringUtils.isEmpty;
import static org.springframework.web.context.support.WebApplicationContextUtils.getRequiredWebApplicationContext;
import static org.usergrid.rest.utils.CORSUtils.allowAllOrigins;
import static org.usergrid.utils.StringUtils.readClasspathFileAsString;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.text.StrSubstitutor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationContext;

public class SwaggerServlet extends HttpServlet implements Filter {

    public static final String SWAGGER_BASE_PATH = "http://localhost:8080";

    public static final Logger logger = LoggerFactory.getLogger(SwaggerServlet.class);

    private static final long serialVersionUID = 1L;

    ServletContext sc;
    Properties properties;

    @Override
    public void init(ServletConfig config) throws ServletException {
        super.init(config);
        logger.info("init(ServletConfig config)");
        if (sc == null) {
            sc = config.getServletContext();
        }
        properties = (Properties) getSpringBeanFromWeb("properties");
        loadSwagger();
    }

    @Override
    public void init(FilterConfig config) throws ServletException {
        logger.info("init(FilterConfig paramFilterConfig)");
        if (sc == null) {
            sc = config.getServletContext();
        }
        properties = (Properties) getSpringBeanFromWeb("properties");
        loadSwagger();
    }

    public Object getSpringBeanFromWeb(String beanName) {
        if (sc == null) {
            return null;
        }
        ApplicationContext appContext = getRequiredWebApplicationContext(sc);
        return appContext.getBean(beanName);
    }

    Map<String, String> pathToJson = new HashMap<String, String>();

    public String loadTempate(String template) {
        String templateString = readClasspathFileAsString(template);
        Map<String, String> valuesMap = new HashMap<String, String>();
        String basePath = properties != null ? properties.getProperty("swagger.basepath", SWAGGER_BASE_PATH)
                : SWAGGER_BASE_PATH;
        valuesMap.put("basePath", basePath);
        StrSubstitutor sub = new StrSubstitutor(valuesMap);
        return sub.replace(templateString);
    }

    public void loadSwagger() {
        logger.info("loadSwagger()");
        pathToJson.put("/resources.json", loadTempate("/swagger/resources.json"));
        pathToJson.put("/applications.json", loadTempate("/swagger/applications.json"));
        pathToJson.put("/management.json", loadTempate("/swagger/management.json"));
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        String path = request.getServletPath();

        logger.info("Swagger request: " + path);

        handleJsonOutput(request, response);

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        try {
            doFilter((HttpServletRequest) request, (HttpServletResponse) response, chain);
        } catch (ClassCastException e) {
            throw new ServletException("non-HTTP request or response");
        }
    }

    public void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
            throws IOException, ServletException {

        if (handleJsonOutput(request, response)) {
            return;
        }

        chain.doFilter(request, response);
    }

    public boolean handleJsonOutput(HttpServletRequest request, HttpServletResponse response) throws IOException {
        String path = request.getServletPath();
        if (isEmpty(path)) {
            path = request.getPathInfo();
        }
        if (isEmpty(path)) {
            return false;
        }
        path = path.toLowerCase();
        if (pathToJson.containsKey(path)) {
            String json = pathToJson.get(path);
            if (json != null) {
                allowAllOrigins(request, response);
                if ("get".equalsIgnoreCase(request.getMethod())) {
                    response.setContentType("application/json");
                    response.getWriter().print(json);
                    return true;
                }
            }
        }
        return false;
    }

}