com.google.sampling.experiential.server.reports.ReportsBackendServlet.java Source code

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Here is the source code for com.google.sampling.experiential.server.reports.ReportsBackendServlet.java

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/*
 * Copyright 2011 Google Inc. All Rights Reserved.
 *
 * 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.google.sampling.experiential.server.reports;

import java.io.ByteArrayOutputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.PrintStream;
import java.sql.SQLException;
import java.util.logging.Logger;

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

import org.apache.commons.codec.digest.DigestUtils;
import org.json.JSONException;

import com.google.appengine.api.ThreadManager;
import com.google.sampling.experiential.datastore.EventServerColumns;
import com.google.sampling.experiential.server.HttpUtil;
import com.google.sampling.experiential.server.ReportJobStatusManager;

/**
 * Servlet that handles report tasks for data
 *
 */
@SuppressWarnings("serial")
public class ReportsBackendServlet extends HttpServlet {

    public static final Logger log = Logger.getLogger(ReportsBackendServlet.class.getName());
    private static final String REPORT_WORKER = "reportworker";

    @Override
    protected void doGet(final HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        final String requestorEmail = getRequestorEmail(req);
        final ReportRequest reportRequestObj = new ReportRequest(req, requestorEmail, REPORT_WORKER);
        final String jobId = getJobId(reportRequestObj);
        final ReportJobStatusManager statusMgr = new ReportJobStatusManager();
        statusMgr.startReport(requestorEmail, jobId);

        final ClassLoader cl = getClass().getClassLoader();
        final Thread thread2 = ThreadManager.createBackgroundThread(new Runnable() {
            @Override
            public void run() {

                log.info("ReportsBackend running");
                Thread.currentThread().setContextClassLoader(cl);
                try {
                    String key = runReport(reportRequestObj, jobId);
                    if (key != null) {
                        statusMgr.completeReport(requestorEmail, jobId, key);
                    } else {
                        statusMgr.failReport(requestorEmail, jobId, "Check server logs for stacktrace");
                    }
                } catch (Throwable e) {
                    final String fullStack = getStackTraceAsString(e);
                    final String string = fullStack.length() > 700 ? fullStack.substring(0, 700) : fullStack;
                    statusMgr.failReport(requestorEmail, jobId,
                            e.getClass() + "." + e.getMessage() + "\n" + string);
                    log.severe("Could not run migration job: " + e.getMessage());
                    log.severe("stacktrace: " + fullStack);
                }
            }
        });
        thread2.start();
        log.info("Leaving reports backend");
        resp.setContentType("text/plain;charset=UTF-8");
        resp.getWriter().println(jobId);
    }

    private String runReport(ReportRequest repRequest, String jobId)
            throws FileNotFoundException, SQLException, JSONException, IOException {
        ReportJob job = ReportLookupTable.getReportBackendName(repRequest.getReportId());
        if (job != null) {
            return job.runReport(repRequest, jobId);
        }
        return null;
    }

    private String getRequestorEmail(HttpServletRequest req) {
        String whoParam = HttpUtil.getParam(req, EventServerColumns.WHO);
        if (whoParam == null) {
            throw new IllegalArgumentException("Must pass the who param");
        }
        return whoParam.toLowerCase();
    }

    public String getJobId(ReportRequest repRequest) {
        final String jobId = repRequest.getReportId() + "_"
                + DigestUtils.md5Hex(repRequest.getWho() + Long.toString(System.currentTimeMillis()));
        log.info("In report backend for job: " + jobId);
        return jobId;
    }

    public String getStackTraceAsString(Throwable e) {
        final ByteArrayOutputStream out = new ByteArrayOutputStream();
        PrintStream pw = new PrintStream(out);
        e.printStackTrace(pw);
        final String string = out.toString();
        return string;
    }
}