org.o3project.odenos.remoteobject.rest.servlet.RestServlet.java Source code

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Here is the source code for org.o3project.odenos.remoteobject.rest.servlet.RestServlet.java

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/*
 * Copyright 2015 NEC 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.o3project.odenos.remoteobject.rest.servlet;

import org.apache.commons.io.IOUtils;
import org.json.simple.JSONValue;
import org.msgpack.MessagePack;
import org.msgpack.type.Value;
import org.o3project.odenos.remoteobject.message.Request;
import org.o3project.odenos.remoteobject.message.Response;
import org.o3project.odenos.remoteobject.rest.Attributes;
import org.o3project.odenos.remoteobject.rest.RESTTranslator;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.URLDecoder;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Rest servlet.
 *
 */
@WebServlet("/*")
public class RestServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    private static final Pattern PATH_PATTERN = Pattern.compile("^/([^/]+)/(.+)");

    private static final Logger logger = LoggerFactory.getLogger(RestServlet.class);

    private final MessagePack messagePack = new MessagePack();

    /*
     * (non-Javadoc)
     *
     * @see
     * javax.servlet.http.HttpServlet#service(javax.servlet.http.HttpServletRequest
     * , javax.servlet.http.HttpServletResponse)
     */
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        Request.Method method;
        try {
            method = Request.Method.valueOf(req.getMethod().toUpperCase());
        } catch (IllegalArgumentException e) {
            super.service(req, resp);
            return;
        }

        do {
            if (!method.equals(Request.Method.GET)) {
                break;
            }

            String root = (String) this.getServletContext().getAttribute("resource.root");
            if (root == null) {
                break;
            }

            String path = root + req.getPathInfo();
            this.logger.debug("Trying to read \"{}\".", path);

            InputStream in = null;
            try {
                in = new FileInputStream(path);
            } catch (FileNotFoundException e) {
                break;
            }

            OutputStream out = resp.getOutputStream();
            IOUtils.copy(in, out);
            try {
                in.close();
            } catch (IOException e) {
                // just ignore.
            }
            return;
        } while (false);

        doRequestToComponent(req, resp, method);
    }

    protected void doRequestToComponent(HttpServletRequest req, HttpServletResponse resp, Request.Method method)
            throws ServletException, IOException {
        Matcher matcher = RestServlet.PATH_PATTERN.matcher(req.getRequestURI());
        if (!matcher.find()) {
            resp.setStatus(HttpServletResponse.SC_NOT_FOUND);
            return;
        }
        String objectId = matcher.group(1);
        String path = matcher.group(2);
        if (req.getQueryString() != null) {
            path = path + "?" + URLDecoder.decode(req.getQueryString(), "utf-8");
        }
        Object reqBody = JSONValue.parse(req.getReader());

        RESTTranslator translator = (RESTTranslator) req.getServletContext()
                .getAttribute(Attributes.REST_TRANSLATOR);
        Response odenosResp;
        try {
            odenosResp = translator.request(objectId, method, path, reqBody);
        } catch (Exception e) {
            this.logger.debug("Failed to request [{}, {}, {}, {}]", objectId, method, path, reqBody, e);
            resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
            return;
        }

        resp.setStatus(odenosResp.statusCode);
        if (!odenosResp.isBodyNull()) {
            Value value;
            try {
                byte[] packed = this.messagePack.write(odenosResp);
                value = this.messagePack.read(packed);
            } catch (IOException e) {
                this.logger.debug("Failed to serialize a response body. /req:[{}, {}, {}, {}]", objectId, method,
                        path, reqBody);
                resp.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
                return;
            }

            resp.getWriter().write(value.asArrayValue().get(1).toString());
        }
    }
}