cc.kune.wave.server.CustomGadgetProviderServlet.java Source code

Introduction

Here is the source code for cc.kune.wave.server.CustomGadgetProviderServlet.java

Source

/**
 * Copyright 2012 Apache Wave
 *
 * 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 cc.kune.wave.server;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.inject.Singleton;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.waveprotocol.box.server.CoreSettings;
import org.waveprotocol.box.server.persistence.file.FileAccountStore;

import cc.kune.core.server.manager.file.FileDownloadManagerUtils;

import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.inject.Inject;
import com.google.inject.name.Named;

@SuppressWarnings("serial")
@Singleton
public class CustomGadgetProviderServlet extends HttpServlet {

    /** The Constant LOG. */
    private static final Logger LOG = Logger.getLogger(FileAccountStore.class.getName());

    private LoadingCache<String, String> jsonCache;

    @Inject
    public CustomGadgetProviderServlet(@Named(CoreSettings.RESOURCE_BASES) final List<String> resourceBases) {
        jsonCache = CacheBuilder.newBuilder().expireAfterWrite(5, TimeUnit.MINUTES)
                .build(new CacheLoader<String, String>() {
                    @Override
                    public String load(final String key) {
                        String jsonString = "";
                        try {
                            jsonString = FileDownloadManagerUtils.getInpuStreamAsString(FileDownloadManagerUtils
                                    .getInputStreamInResourceBases(resourceBases, "/others/jsongadgets.json"));

                        } catch (final IOException e) {
                            LOG.log(Level.WARNING, "Error while loading gadgets json", e);
                        }
                        return jsonString;
                    }
                });
    }

    @Override
    protected void doGet(final HttpServletRequest request, final HttpServletResponse response) throws IOException {
        try {
            final String jsonString = jsonCache.get("");
            if (jsonString.equals("")) {
                response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR,
                        "Error loading json data from file");
            } else {
                final PrintWriter out = response.getWriter();
                out.print(jsonCache.get(""));
                out.flush();
            }
        } catch (final ExecutionException ex) {
            throw new IOException(ex);
        }
    }
}