com.bagdemir.eboda.handler.MemoryResourceHandler.java Source code

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Here is the source code for com.bagdemir.eboda.handler.MemoryResourceHandler.java

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/*
 *   Copyright (C) 2013 "Erhan Bagdemir"
 *
 *   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 3 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 com.bagdemir.eboda.handler;

import static com.bagdemir.eboda.utils.HttpUtils.responseWith404;
import static com.bagdemir.eboda.utils.HttpUtils.responseWith501;
import static com.bagdemir.eboda.utils.HttpUtils.sendBody;
import static com.bagdemir.eboda.utils.HttpUtils.sendHttpOKHeaders;
import static com.bagdemir.eboda.utils.Statics.HTTP_CONTENT_TYPE;
import static com.bagdemir.eboda.utils.Statics.HTTP_GET;

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

import org.apache.commons.io.IOUtils;
import org.apache.log4j.Logger;

import com.bagdemir.eboda.resource.ByteArrayResource;
import com.bagdemir.eboda.resource.Resource;
import com.bagdemir.eboda.utils.HttpUtils;
import com.bagdemir.eboda.utils.Statics;
import com.google.common.collect.ImmutableMap;
import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;

public class MemoryResourceHandler implements HttpHandler {

    public static final Logger LOGGER = Logger.getLogger(MemoryResourceHandler.class);
    public static final String MIME_IMAGE_GIF = "image/gif";
    private Map<String, Resource> inMemoryResources = new HashMap<>();
    private String[] gifImages = new String[] { "icons/folder.gif", "icons/back.gif", "icons/file.gif" };

    public MemoryResourceHandler() {
        for (final String resourceName : gifImages) {
            readResourceIfExists(resourceName);
        }
    }

    private void readResourceIfExists(final String resourceName) {
        try {
            final byte[] bytes = IOUtils.toByteArray(getClass().getClassLoader().getResource(resourceName));
            final ByteArrayResource byteArrayResource = new ByteArrayResource(bytes, MIME_IMAGE_GIF);
            inMemoryResources.put(resourceName, byteArrayResource);
        } catch (IOException e) {
            LOGGER.error(e);
        }
    }

    @Override
    public void handle(final HttpExchange httpExchange) throws IOException {
        LOGGER.info(String.format("Received request for: %s", httpExchange.getRequestURI()));
        if (isGetRequest(httpExchange)) {
            final String inMemoryResourceKey = getKeyForResource(httpExchange);
            if (inMemoryResources.containsKey(inMemoryResourceKey)) {
                final Resource resource = inMemoryResources.get(inMemoryResourceKey);
                sendResourceToClient(httpExchange, resource);
            } else {
                responseWith404(httpExchange, false);
            }
        } else {
            responseWith501(httpExchange, false);
        }
    }

    private void sendResourceToClient(final HttpExchange httpExchange, final Resource resoure) {
        final ImmutableMap<String, String> headerInfo = ImmutableMap.of(HTTP_CONTENT_TYPE,
                resoure.getContentType());
        sendHttpOKHeaders(httpExchange, headerInfo);
        sendBody(httpExchange, resoure.getBytes());
    }

    private String getKeyForResource(final HttpExchange httpExchange) {
        final String requestedUri = HttpUtils.getPathVariable(httpExchange);
        return requestedUri.replace(Statics.SERVER_INTERNAL_CONTEXT, "");
    }

    private boolean isGetRequest(final HttpExchange httpExchange) {
        return httpExchange.getRequestMethod().equalsIgnoreCase(HTTP_GET);
    }
}