com.ca.dvs.app.dvs_servlet.resources.ROOT.java Source code

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Here is the source code for com.ca.dvs.app.dvs_servlet.resources.ROOT.java

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/*******************************************************************************
 * Copyright (c) 2015 CA.  All rights reserved.
 *
 * This source file is licensed under the terms of the Eclipse Public License 1.0
 * For the full text of the EPL please see https://www.eclipse.org/legal/epl-v10.html
 *******************************************************************************/
/**
 * 
 */
package com.ca.dvs.app.dvs_servlet.resources;

import java.io.StringWriter;
import java.io.Writer;
import java.util.LinkedHashMap;
import java.util.Map;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.Response;
import javax.xml.XMLConstants;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.apache.log4j.Logger;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

/**
 * DVS Servlet root REST resource
 * <p>
 * @author CA Technologies
 * @version 1
 */
@Path("/")
public class ROOT {

    private static Logger log = Logger.getLogger(ROOT.class);

    /**
     * Produce a service document for the DVS servlet
     * <p>
     * @return a service document
     */
    @GET
    @Path("")
    @Produces(MediaType.TEXT_HTML)
    public Response getRoot() {

        Response response = null;

        log.info("GET /");

        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        DocumentBuilder builder;
        try {
            builder = dbf.newDocumentBuilder();

            Document document = builder.newDocument();
            Element elHtml = document.createElement("html");

            Element elHead = document.createElement("head");
            Element elH1 = document.createElement("h1");

            elH1.setTextContent("DVS Servlet");
            elHead.appendChild(elH1);

            Element elTitle = document.createElement("title");

            elTitle.setTextContent("Dynamic Virtual Services");

            Element elBody = document.createElement("body");
            Element elP1 = document.createElement("p");
            elP1.setTextContent("Documentation text goes here");
            elBody.appendChild(elP1);

            elHtml.appendChild(elHead);
            elHtml.appendChild(elTitle);
            elHtml.appendChild(elBody);

            document.appendChild(elHtml);

            StringWriter sw = new StringWriter();
            prettyPrint(document, sw);

            response = Response.status(200).entity(sw.toString()).build();

        } catch (Exception e) {

            e.printStackTrace();
            response = Response.status(500).entity(e.getMessage()).build();

        }

        return response;
    }

    /**
     * @return HTTP response containing DVS servlet configuration parameters in JSON format
     */
    @GET
    @Path("config")
    @Produces(MediaType.APPLICATION_JSON)
    public Response getConfig() {

        log.info("GET /config");

        Map<String, Object> configMap = new LinkedHashMap<String, Object>();

        try {
            Context initialContext = new InitialContext();
            Context envContext = (Context) initialContext.lookup("java:comp/env");

            configMap.put("vseServerUrl", envContext.lookup("vseServerUrl"));
            configMap.put("vseServicePortRange", envContext.lookup("vseServicePortRange"));
            configMap.put("vseServiceReadyWaitSeconds", envContext.lookup("vseServiceReadyWaitSeconds"));

        } catch (NamingException e) {
            e.printStackTrace();
        }

        GsonBuilder gsonBuilder = new GsonBuilder();

        gsonBuilder.setPrettyPrinting();
        gsonBuilder.serializeNulls();

        Gson gson = gsonBuilder.create();

        Response response = Response.status(200).entity(gson.toJson(configMap)).build();

        return response;
    }

    /**
     * Format a DOM Document so that it is visually appealing
     *  
     * @param xml Document to transform
     * @param writer used for transformation output
     * @throws Exception when transformation fails
     */
    public static final void prettyPrint(Document xml, Writer writer) throws Exception {

        TransformerFactory tf = TransformerFactory.newInstance();

        //tf.setFeature(XMLConstants.ACCESS_EXTERNAL_DTD, false); <-- Fortify recommended.  Eclipse compiled ok.  ANT failed.
        tf.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true); // Per web article, this is a suitable replacement for setting ACCESS_EXTERNAL_DTD, false (above)

        Transformer trans = tf.newTransformer();

        trans.setOutputProperty(OutputKeys.ENCODING, "UTF-8");
        trans.setOutputProperty(OutputKeys.INDENT, "yes");
        trans.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");

        trans.transform(new DOMSource(xml), new StreamResult(writer));

    }

}