com.infosupport.service.LPRServiceCaller.java Source code

Introduction

Here is the source code for com.infosupport.service.LPRServiceCaller.java

Source

package com.infosupport.service;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.methods.multipart.FilePart;
import org.apache.commons.httpclient.methods.multipart.MultipartRequestEntity;
import org.apache.commons.httpclient.methods.multipart.Part;
import org.apache.commons.httpclient.methods.multipart.StringPart;
import org.json.JSONException;
import org.json.JSONObject;

import com.infosupport.activity.TaskDelegate;

import android.os.AsyncTask;
import android.util.Log;

/**
 * The LPRServiceCaller does a call to the OpenANPR api to find the licenses in
 * a picture.
 * 
 * @author Mike
 * @version 2.1
 */
public class LPRServiceCaller extends AsyncTask<String, JSONObject, JSONObject> {

    private static final String TAG = "OCRServiceCaller";
    private static final String UPLOADURL = "http://demo.openalpr.com:8010/upload";
    private static final String GETURL = "http://demo.openalpr.com:8010/status?nonce=123456789";

    public static final int READY = 3;

    private File image;
    private TaskDelegate delegate;

    public LPRServiceCaller(TaskDelegate delegate, File image) {
        this.delegate = delegate;
        this.image = image;
    }

    @Override
    protected JSONObject doInBackground(String... params) {
        postData(UPLOADURL, image);
        int job_status = 1;
        JSONObject json = null;
        while (job_status < READY) {
            try {
                Thread.sleep(300);
            } catch (InterruptedException e1) {
                e1.printStackTrace();
            }
            json = doGet(GETURL);
            try {
                job_status = Integer.parseInt(json.get("job_status").toString());
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
        return json;
    }

    @Override
    protected void onPostExecute(JSONObject result) {
        delegate.taskCompletionResult(result);
    }

    public static void postData(String urlString, File file) {
        try {
            PostMethod postMessage = new PostMethod(urlString);
            Part[] parts = { new FilePart("lpimage", file), new StringPart("country", "eu"),
                    new StringPart("nonce", "123456789") };
            postMessage.setRequestEntity(new MultipartRequestEntity(parts, postMessage.getParams()));
            HttpClient client = new HttpClient();
            client.executeMethod(postMessage);
        } catch (IOException e) {
            Log.w(TAG, "IOException, waarschijnlijk geen internet connectie aanwezig...");
        }
    }

    public static JSONObject doGet(String urlString) {
        String json = null;
        try {
            URL url = new URL(urlString);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            conn.setRequestProperty("Accept", "application/json");

            if (conn.getResponseCode() != 200) {
                throw new RuntimeException("Failed : HTTP error code : " + conn.getResponseCode());
            }

            BufferedReader br = new BufferedReader(new InputStreamReader((conn.getInputStream())));

            String output;
            while ((output = br.readLine()) != null) {
                json = output;
                System.out.println(json + "from doGet");
            }
            conn.disconnect();
        } catch (IOException e) {
            Log.w(TAG, "IOException, waarschijnlijk geen internet connectie aanwezig...");
        }
        JSONObject jsonObject = null;
        try {
            jsonObject = new JSONObject(json);
        } catch (JSONException e) {
            Log.e(TAG, "Kon geen JsonObject maken van het response");
        }
        return jsonObject;
    }

}