我正在使用 PHP MySQL 服务器模型。我想解码此代码发送到服务器的 JSON 数据。任何帮助，将不胜感激。该应用程序将当前 GPS 坐标作为 JSON 数组对象发送到输入的服务器。我想对其进行解码以与其他安卓用户分享。非常感谢。这是安卓代码。
public class TrackerService extends Service {
private static final String TAG = "TripTracker/Service";
private final String updatesCache = "updates.cache";
public static TrackerService service;
private NotificationManager nm;
private Notification notification;
private static boolean isRunning = false;
private String freqString;
private int freqSeconds;
private String endpoint;
private final int MAX_RING_SIZE = 15;
private LocationListener locationListener;
private AlarmManager alarmManager;
private PendingIntent pendingAlarm;
private static volatile PowerManager.WakeLock wakeLock;
private AsyncTask httpPoster;
ArrayList<LogMessage> mLogRing = new ArrayList<LogMessage>();
ArrayList<Messenger> mClients = new ArrayList<Messenger>();
ArrayList<List> mUpdates = new ArrayList<List>();
final ReentrantReadWriteLock updateLock = new ReentrantReadWriteLock();
final Messenger mMessenger = new Messenger(new IncomingHandler());
static final int MSG_REGISTER_CLIENT = 1;
static final int MSG_UNREGISTER_CLIENT = 2;
static final int MSG_LOG = 3;
static final int MSG_LOG_RING = 4;
@Override
public IBinder onBind(Intent intent) {
return mMessenger.getBinder();
}
@Override
public void onCreate() {
super.onCreate();
TrackerService.service = this;
endpoint = Prefs.getEndpoint(this);
freqSeconds = 0;
freqString = null;
freqString = Prefs.getUpdateFreq(this);
if (freqString != null && !freqString.equals("")) {
try {
Pattern p = Pattern.compile("(\\d+)(m|h|s)");
Matcher m = p.matcher(freqString);
m.find();
freqSeconds = Integer.parseInt(m.group(1));
if (m.group(2).equals("h"))
freqSeconds *= (60 * 60);
else if (m.group(2).equals("m"))
freqSeconds *= 60;
}
catch (Exception e) {
}
}
if (endpoint == null || endpoint.equals("")) {
logText("invalid endpoint, stopping service");
stopSelf();
}
if (freqSeconds < 1) {
logText("invalid frequency (" + freqSeconds + "), stopping " +
"service");
stopSelf();
}
readCache();
showNotification();
isRunning = true;
/* we're not registered yet, so this will just log to our ring buffer,
* but as soon as the client connects we send the log buffer anyway */
logText("service started, requesting location update every " +
freqString);
/* findAndSendLocation() will callback to this */
locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
sendLocation(location);
}
public void onStatusChanged(String provider, int status,
Bundle extras) {
}
public void onProviderEnabled(String provider) {
}
public void onProviderDisabled(String provider) {
}
};
/* we don't need to be exact in our frequency, try to conserve at least
* a little battery */
alarmManager = (AlarmManager)getSystemService(ALARM_SERVICE);
Intent i = new Intent(this, AlarmBroadcast.class);
pendingAlarm = PendingIntent.getBroadcast(this, 0, i, 0);
alarmManager.setInexactRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP,
SystemClock.elapsedRealtime(), freqSeconds * 1000, pendingAlarm);
}
@Override
public void onDestroy() {
super.onDestroy();
if (httpPoster != null)
httpPoster.cancel(true);
try {
LocationManager locationManager = (LocationManager)
this.getSystemService(Context.LOCATION_SERVICE);
locationManager.removeUpdates(locationListener);
}
catch (Exception e) {
}
/* kill persistent notification */
nm.cancelAll();
if (pendingAlarm != null)
alarmManager.cancel(pendingAlarm);
isRunning = false;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
return START_STICKY;
}
/* must be done inside of updateLock */
public void cacheUpdates() {
OutputStreamWriter cacheStream = null;
try {
FileOutputStream cacheFile = TrackerService.this.openFileOutput(
updatesCache, Activity.MODE_PRIVATE);
cacheStream = new OutputStreamWriter(cacheFile, "UTF-8");
/* would be nice to just serialize mUpdates but it's not
* serializable. create a json array of json objects, each object
* having each key/value pair of one location update. */
JSONArray ja = new JSONArray();
for (int i = 0; i < mUpdates.size(); i++) {
List<NameValuePair> pair = mUpdates.get(i);
JSONObject jo = new JSONObject();
for (int j = 0; j < pair.size(); j++) {
try {
jo.put(((NameValuePair)pair.get(j)).getName(),
pair.get(j).getValue());
}
catch (JSONException e) {
}
}
ja.put(jo);
}
cacheStream.write(ja.toString());
cacheFile.getFD().sync();
}
catch (IOException e) {
Log.w(TAG, e);
}
finally {
if (cacheStream != null) {
try {
cacheStream.close();
}
catch (IOException e) {
}
}
}
}
/* read json cache into mUpdates */
public void readCache() {
updateLock.writeLock().lock();
InputStreamReader cacheStream = null;
try {
FileInputStream cacheFile = TrackerService.this.openFileInput(
updatesCache);
StringBuffer buf = new StringBuffer("");
byte[] bbuf = new byte[1024];
int len;
while ((len = cacheFile.read(bbuf)) != -1)
buf.append(new String(bbuf));
JSONArray ja = new JSONArray(new String(buf));
mUpdates = new ArrayList<List>();
for (int j = 0; j < ja.length(); j++) {
JSONObject jo = ja.getJSONObject(j);
List<NameValuePair> nvp = new ArrayList<NameValuePair>(2);
Iterator<String> i = jo.keys();
while (i.hasNext()) {
String k = (String)i.next();
String v = jo.getString(k);
nvp.add(new BasicNameValuePair(k, v));
}
mUpdates.add(nvp);
}
if (mUpdates.size() > 0)
logText("read " + mUpdates.size() + " update" +
(mUpdates.size() == 1 ? "" : "s") + " from cache");
}
catch (JSONException e) {
}
catch (FileNotFoundException e) {
}
catch (IOException e) {
Log.w(TAG, e);
}
finally {
if (cacheStream != null) {
try {
cacheStream.close();
}
catch (IOException e) {
}
}
}
updateLock.writeLock().unlock();
}
/* called within wake lock from broadcast receiver, but assert that we have
* it so we can keep it longer when we return (since the location request
* uses a callback) and then free it when we're done running through the
* queue */
public void findAndSendLocation() {
if (wakeLock == null) {
PowerManager pm = (PowerManager)this.getSystemService(
Context.POWER_SERVICE);
/* we don't need the screen on */
wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
"triptracker");
wakeLock.setReferenceCounted(true);
}
if (!wakeLock.isHeld())
wakeLock.acquire();
LocationManager locationManager = (LocationManager)
this.getSystemService(Context.LOCATION_SERVICE);
locationManager.requestSingleUpdate(LocationManager.GPS_PROVIDER,
locationListener, null);
}
public static boolean isRunning() {
return isRunning;
}
private void showNotification() {
nm = (NotificationManager)getSystemService(NOTIFICATION_SERVICE);
notification = new Notification(R.drawable.icon,
"Trip Tracker Started", System.currentTimeMillis());
PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
new Intent(this, MainActivity.class), 0);
notification.setLatestEventInfo(this, "Trip Tracker",
"Sending location every " + freqString, contentIntent);
notification.flags = Notification.FLAG_ONGOING_EVENT;
nm.notify(1, notification);
}
private void updateNotification(String text) {
if (nm != null) {
PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
new Intent(this, MainActivity.class), 0);
notification.setLatestEventInfo(this, "Trip Tracker", text,
contentIntent);
notification.when = System.currentTimeMillis();
nm.notify(1, notification);
}
}
public void logText(String log) {
LogMessage lm = new LogMessage(new Date(), log);
mLogRing.add(lm);
if (mLogRing.size() > MAX_RING_SIZE)
mLogRing.remove(0);
updateNotification(log);
for (int i = mClients.size() - 1; i >= 0; i--) {
try {
Bundle b = new Bundle();
b.putString("log", log);
Message msg = Message.obtain(null, MSG_LOG);
msg.setData(b);
mClients.get(i).send(msg);
}
catch (RemoteException e) {
/* client is dead, how did this happen */
mClients.remove(i);
}
}
}
/* flatten an array of NameValuePairs into an array of
* locations[0]latitude, locations[1]latitude, etc. */
public List<NameValuePair> getUpdatesAsArray() {
List<NameValuePair> pairs = new ArrayList<NameValuePair>(2);
for (int i = 0; i < mUpdates.size(); i++) {
List<NameValuePair> pair = mUpdates.get(i);
for (int j = 0; j < pair.size(); j++)
pairs.add(new BasicNameValuePair("locations[" + i + "][" +
((NameValuePair)pair.get(j)).getName() + "]",
pair.get(j).getValue()));
}
return pairs;
}
public int getUpdatesSize() {
return mUpdates.size();
}
public void removeUpdate(int i) {
mUpdates.remove(i);
}
private void sendLocation(Location location) {
List<NameValuePair> pairs = new ArrayList<NameValuePair>(2);
pairs.add(new BasicNameValuePair("time",
String.valueOf(location.getTime())));
pairs.add(new BasicNameValuePair("latitude",
String.valueOf(location.getLatitude())));
pairs.add(new BasicNameValuePair("longitude",
String.valueOf(location.getLongitude())));
pairs.add(new BasicNameValuePair("speed",
String.valueOf(location.getSpeed())));
/* push these pairs onto the queue, and only run the poster if another
* one isn't running already (if it is, it will keep running through
* the queue until it's empty) */
updateLock.writeLock().lock();
mUpdates.add(pairs);
int size = service.getUpdatesSize();
cacheUpdates();
updateLock.writeLock().unlock();
logText("location " +
(new DecimalFormat("#.######").format(location.getLatitude())) +
", " +
(new DecimalFormat("#.######").format(location.getLongitude())) +
(size <= 1 ? "" : " (" + size + " queued)"));
if (httpPoster == null ||
httpPoster.getStatus() == AsyncTask.Status.FINISHED)
(httpPoster = new HttpPoster()).execute();
}
class IncomingHandler extends Handler {
@Override
public void handleMessage(Message msg) {
switch (msg.what) {
case MSG_REGISTER_CLIENT:
mClients.add(msg.replyTo);
/* respond with our log ring to show what we've been up to */
try {
Message replyMsg = Message.obtain(null, MSG_LOG_RING);
replyMsg.obj = mLogRing;
msg.replyTo.send(replyMsg);
}
catch (RemoteException e) {
}
break;
case MSG_UNREGISTER_CLIENT:
mClients.remove(msg.replyTo);
break;
default:
super.handleMessage(msg);
}
}
}
/* Void as first arg causes a crash, no idea why
E/AndroidRuntime(17157): Caused by: java.lang.ClassCastException: java.lang.Object[] cannot be cast to java.lang.Void[]
*/
class HttpPoster extends AsyncTask<Object, Void, Boolean> {
@Override
protected Boolean doInBackground(Object... o) {
TrackerService service = TrackerService.service;
int retried = 0;
int max_retries = 4;
while (true) {
if (isCancelled())
return false;
boolean failed = false;
updateLock.writeLock().lock();
List<NameValuePair> pairs = service.getUpdatesAsArray();
int pairSize = service.getUpdatesSize();
updateLock.writeLock().unlock();
AndroidHttpClient httpClient =
AndroidHttpClient.newInstance("TripTracker");
try {
HttpPost post = new HttpPost(endpoint);
post.setEntity(new UrlEncodedFormEntity(pairs));
HttpResponse resp = httpClient.execute(post);
int httpStatus = resp.getStatusLine().getStatusCode();
if (httpStatus == 200) {
/* all good, we can remove everything we've sent from
* the queue (but not just clear it, in case another
* one jumped onto the end while we were here) */
updateLock.writeLock().lock();
for (int i = pairSize - 1; i >= 0; i--)
service.removeUpdate(i);
updateLock.writeLock().unlock();
}
else {
logText("POST failed to " + endpoint + ": got " +
httpStatus + " status");
failed = true;
}
}
catch (Exception e) {
logText("POST failed to " + endpoint + ": " + e);
Log.w(TAG, e);
failed = true;
}
finally {
if (httpClient != null)
httpClient.close();
}
if (failed) {
/* if our initial request failed, snooze for a bit and try
* again, the server might not be reachable */
SystemClock.sleep(15 * 1000);
if (++retried > max_retries) {
/* give up since we're holding the wake lock open for
* too long. we'll get it next time, champ. */
logText("too many failures, retrying later (queue " +
"size " + service.getUpdatesSize() + ")");
break;
}
}
else
retried = 0;
int q = 0;
updateLock.writeLock().lock();
q = service.getUpdatesSize();
cacheUpdates();
updateLock.writeLock().unlock();
if (q == 0)
break;
/* otherwise, run through the rest of the queue */
}
return false;
}
protected void onPostExecute(Boolean b) {
if (wakeLock != null && wakeLock.isHeld())
wakeLock.release();
}
}
}