net.peterkuterna.appengine.apps.devoxxsched.util.Md5Calculator.java Source code

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Here is the source code for net.peterkuterna.appengine.apps.devoxxsched.util.Md5Calculator.java

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/*
 * Copyright 2011 Peter Kuterna
 * 
 * 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 net.peterkuterna.appengine.apps.devoxxsched.util;

import java.io.IOException;
import java.io.InputStream;
import java.math.BigInteger;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.logging.Logger;

import net.peterkuterna.appengine.apps.devoxxsched.c2dm.C2DMMessage;

import org.apache.commons.io.IOUtils;

public class Md5Calculator {

    private static final Logger log = Logger.getLogger(Md5Calculator.class.getName());

    private String requestUri;

    public Md5Calculator(final String requestUri) {
        this.requestUri = requestUri;
    }

    public String calculateMd5() {
        final byte[] response = getResponse(requestUri);
        if (response != null) {
            try {
                MessageDigest mdEnc = MessageDigest.getInstance("MD5");
                mdEnc.update(response);
                return new BigInteger(1, mdEnc.digest()).toString(16);
            } catch (NoSuchAlgorithmException e) {
            }
        }
        return null;
    }

    private byte[] getResponse(final String requestUri) {
        try {
            URL url = new URL(requestUri);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestProperty("User-agent", "Devoxx Schedule AppEngine Backend");
            connection.setDoOutput(true);
            connection.setRequestMethod("GET");
            connection.setConnectTimeout(5000);
            connection.setReadTimeout(120 * 1000);
            connection.setRequestProperty("Cache-Control", "no-cache,max-age=0");
            connection.setRequestProperty("Pragma", "no-cache");
            InputStream response = connection.getInputStream();
            log.info("response = " + connection.getResponseCode());
            if (connection.getResponseCode() == 200) {
                return IOUtils.toByteArray(response);
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        return null;
    }

}