com.hitkoDev.chemApp.rest.LoadDataTask.java Source code

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Here is the source code for com.hitkoDev.chemApp.rest.LoadDataTask.java

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/*
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package com.hitkoDev.chemApp.rest;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.AsyncTask;
import com.hitkoDev.chemApp.ChemApp;
import com.hitkoDev.chemApp.R;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.Response;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import org.json.JSONObject;

/**
 *
 * @author hitno
 */
public class LoadDataTask extends AsyncTask<String, Void, String> {

    private final Context context;
    private final OnJSONResponseListener listener;
    private final File cache;
    private File file;

    public LoadDataTask(Context c, OnJSONResponseListener l) {
        super();
        context = c;
        listener = l;
        cache = context.getExternalCacheDir();
    }

    private String buildURL(String... urls) {
        StringBuilder url = new StringBuilder(context.getString(R.string.rest_base));
        for (String s : urls) {
            url.append(s).append('/');
        }
        return url.toString();
    }

    @Override
    protected String doInBackground(String... urls) {
        String url = buildURL(urls);
        file = new File(cache, IOLib.md5(url) + ".json");
        if (checkNetwork()) {
            OkHttpClient client = ChemApp.client;
            Request request = new Request.Builder().url(url).build();
            try {
                Response response = client.newCall(request).execute();
                return response.body().string();
            } catch (Exception e) {
                return "Unable to retrieve web page. URL may be invalid.";
            }
        } else if (file.exists()) {
            try (InputStream is = new FileInputStream(file)) {
                return IOLib.readStream(is);
            } catch (Exception ex) {
                return ex.toString();
            }
        } else {
            return "No network or cached files";
        }
    }

    @Override
    protected void onPostExecute(String result) {
        JSONObject json;
        try {
            json = new JSONObject(result.replaceAll("&nbsp;", " "));
        } catch (Exception ex) {
            listener.onFail(result);
            return;
        }

        try {
            if (json.has("success") && !json.getBoolean("success")) {
                throw new Exception(json.has("message") ? json.getString("message") : "Unknown response");
            }
            new StoreFileTask().execute(result);
            if (listener != null) {
                listener.onSuccess(json);
            }
        } catch (Exception ex) {
            listener.onFail(ex.toString());
        }
    }

    public boolean checkNetwork() {
        ConnectivityManager connMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
        return networkInfo != null && networkInfo.isConnected();
    }

    private class StoreFileTask extends AsyncTask<String, Void, Void> {

        @Override
        protected Void doInBackground(String... data) {
            String result = data[0];

            try (OutputStream os = new FileOutputStream(file)) {
                os.write(result.getBytes());
            } catch (Exception ex) {
            }

            return null;
        }

    }

}