de.uni.stuttgart.informatik.ToureNPlaner.Net.Handler.SyncCoreLoader.java Source code

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Here is the source code for de.uni.stuttgart.informatik.ToureNPlaner.Net.Handler.SyncCoreLoader.java

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/*
 * Copyright 2013 ToureNPlaner
 *
 *    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 de.uni.stuttgart.informatik.ToureNPlaner.Net.Handler;

import android.util.Log;
import de.uni.stuttgart.informatik.ToureNPlaner.ClientSideCompute.ClientGraph;
import de.uni.stuttgart.informatik.ToureNPlaner.ClientSideCompute.NullGraph;
import de.uni.stuttgart.informatik.ToureNPlaner.ClientSideCompute.SimpleGraph;
import de.uni.stuttgart.informatik.ToureNPlaner.Net.JacksonManager;
import de.uni.stuttgart.informatik.ToureNPlaner.ToureNPlanerApplication;
import org.apache.commons.io.input.TeeInputStream;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Date;

/**
 * @author Niklas Schnelle
 */
public class SyncCoreLoader {

    public int coreLevel = 40;
    private static final String corePrefix = "core";
    private static final String coreSuffix = ".json";
    private static final String pathPrefix = "/cores/";
    private String coreURL = null;
    private ClientGraph core = null;
    private static final String TAG = "ToureNPlaner";

    public SyncCoreLoader() {
    }

    public void setURL(String url) {
        coreURL = url;
    }

    public void setLevel(int level) {
        coreLevel = level;
    }

    private InputStream readCoreFileFromNetAndCache() throws IOException {
        HttpURLConnection con = null;
        try {
            URL url = new URL(coreURL + pathPrefix + corePrefix + coreLevel + coreSuffix);
            con = (HttpURLConnection) url.openConnection();
            File cacheDirFile = ToureNPlanerApplication.getContext().getExternalCacheDir();
            Log.d(TAG, "Trying to download core to " + cacheDirFile.getAbsolutePath() + corePrefix + coreLevel
                    + coreSuffix);
            FileOutputStream coreFileStream = new FileOutputStream(
                    new File(cacheDirFile, corePrefix + coreLevel + coreSuffix));
            Log.d(TAG, "Content-Length: " + con.getContentLength());
            InputStream in = new BufferedInputStream(con.getInputStream());
            TeeInputStream teeStream = new TeeInputStream(in, coreFileStream, true);
            return teeStream;

        } catch (MalformedURLException e) {
            e.printStackTrace();
            if (con != null) {
                con.disconnect();
            }
            return null;
        }
    }

    private long getLastModifiedOnServer() throws IOException {
        HttpURLConnection con = null;
        long result = new Date().getTime();
        try {
            URL url = new URL(coreURL + pathPrefix + corePrefix + coreLevel + coreSuffix);
            con = (HttpURLConnection) url.openConnection();

            con.setRequestMethod("HEAD");
            con.setDoInput(true);
            con.setAllowUserInteraction(false);
            result = con.getHeaderFieldDate("Last-Modified", result);
            Log.d(TAG, "Last modified is parsed " + new Date(result));

        } catch (MalformedURLException e) {
            e.printStackTrace();
            return result;
        } finally {
            if (con != null) {
                con.disconnect();
            }
        }
        return result;
    }

    private InputStream readCoreFileCached(File coreFile) throws IOException {
        if (getLastModifiedOnServer() > coreFile.lastModified() - 1000 * 60 * 10) {
            return readCoreFileFromNetAndCache();
        }
        return new FileInputStream(coreFile);
    }

    public synchronized SimpleGraph getCoreGraph() throws IOException {
        if (core == null) {
            assert coreURL != null : "Core URL was not set before trying to getCoreGraph";
            File cacheDirFile = ToureNPlanerApplication.getContext().getExternalCacheDir();
            File coreFile = new File(cacheDirFile, corePrefix + coreLevel + coreSuffix);
            InputStream coreFileStream = null;
            if (!coreFile.exists()) {
                Log.d(TAG, "Core does not exist");
                coreFileStream = readCoreFileFromNetAndCache();
            } else {
                Log.d(TAG, "Core exists");
                coreFileStream = readCoreFileCached(coreFile);
            }
            try {
                core = ClientGraph.readClientGraph(new NullGraph(), JacksonManager.ContentType.JSON,
                        coreFileStream);
                Log.d(TAG, "Nodes: " + core.getNodeCount());
            } catch (Exception ex) {
                // We might have messed up our cached Core, delete it
                // so we don't stumble upon it
                if (coreFile.exists()) {
                    Log.e(TAG, "Deleting core because of Exception");
                    coreFile.delete();
                }
                core = null;
            }
        } else {
            Log.d(TAG, "Core is loaded");
        }

        return core;
    }
}