com.cognifide.aet.rest.LockServlet.java Source code

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Here is the source code for com.cognifide.aet.rest.LockServlet.java

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/**
 * Automated Exploratory Tests
 *
 * Copyright (C) 2013 Cognifide Limited
 *
 * 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 com.cognifide.aet.rest;

import com.google.gson.Gson;

import org.apache.commons.lang3.StringUtils;
import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.ConfigurationPolicy;
import org.apache.felix.scr.annotations.Deactivate;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.Service;
import org.osgi.service.http.HttpService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@Service
@Component(label = "LocksServlet", description = "Provides lock services for clients", immediate = true, metatype = true, policy = ConfigurationPolicy.IGNORE)
public class LockServlet extends HttpServlet {

    private static final long serialVersionUID = 101244102274582495L;

    private static final Logger LOGGER = LoggerFactory.getLogger(LockServlet.class);

    private static final String VALUE_PARAM = "value";

    private static final String APPLICATION_JSON_CONTENT_TYPE = "application/json";

    private static final Gson GSON = new Gson();

    @Reference
    private transient HttpService httpService;

    @Reference
    private LockService lockService;

    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        if (LOGGER.isDebugEnabled()) {
            LOGGER.debug("GET: " + req.toString());
        }
        resp.setContentType(APPLICATION_JSON_CONTENT_TYPE);

        String key = getKey(req);
        if (StringUtils.isBlank(key)) {
            resp.getWriter().write(GSON.toJson(getLocks()));
        } else {
            resp.getWriter().write(GSON.toJson(lockService.isLockPresent(key)));
        }
        resp.flushBuffer();
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        if (LOGGER.isDebugEnabled()) {
            LOGGER.debug("POST: " + req.toString());
        }
        resp.setContentType(APPLICATION_JSON_CONTENT_TYPE);
        String value = req.getParameter(VALUE_PARAM);
        String key = getKey(req);
        if (StringUtils.isBlank(key) || StringUtils.isBlank(value)) {
            resp.setStatus(404);
        } else if (lockService.trySetLock(key, value)) {
            resp.setStatus(200);
        } else {
            resp.setStatus(409);
        }
        resp.flushBuffer();
    }

    @Override
    protected void doPut(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        if (LOGGER.isDebugEnabled()) {
            LOGGER.debug("PUT: " + req.toString());
        }
        resp.setContentType(APPLICATION_JSON_CONTENT_TYPE);
        String value = req.getParameter(VALUE_PARAM);
        String key = getKey(req);
        if (StringUtils.isBlank(key) || StringUtils.isBlank(value)) {
            resp.setStatus(404);
        } else {
            lockService.setLock(key, value);
        }
        resp.flushBuffer();
    }

    @Override
    public void init(ServletConfig config) throws ServletException {
        LOGGER.info("Initializing " + config.getServletName());
    }

    private String getLocks() {
        return lockService.getAllLocks().toString();
    }

    private String getKey(HttpServletRequest req) {
        return StringUtils.substringAfter(req.getRequestURI(), Helper.getLocksPath()).replace(Helper.PATH_SEPARATOR,
                "");
    }

    @Activate
    public void start() {
        LOGGER.debug("Registering servlet at " + Helper.getLocksPath());
        try {
            httpService.registerServlet(Helper.getLocksPath(), this, null, null);
        } catch (Exception e) {
            LOGGER.error("Failed to register servlet at " + Helper.getLocksPath(), e);
        }
    }

    @Deactivate
    public void stop() {
        httpService.unregister(Helper.getLocksPath());
        httpService = null;
    }

}