在Android中后台加载数据

Question

I'm trying to do certain operations like creating a table and inserting 720 rows at initial launch of the application which takes some time, so I decided to run it in background. Please see the code below,

MainActivity.java

DatabaseHandler dbhandler = new DatabaseHandler(this);
this.progressDialog = ProgressDialog.show(this, "Please wait...",
            "Downloading Passengers Information...", true, false);

new DownloadTask().execute();


private class DownloadTask extends AsyncTask<String, Void, Object> {

    @Override
    protected Object doInBackground(String... args) {

        for (int i = 1; i <= 5; i++) {
            for (int j = 0; j < 11; j++) {
                value = jedis.hget("passengerInfo",
                        String.valueOf(i + (char) (asciiA) + j)); //this will get the data from hash table passengerInfo created in Redis
                if (value != null) {
                    addSeat = String.valueOf(i + (char) (asciiA) + j);
                    paxInfo = value.split(",");
                    passName = paxInfo[0];
                    passAge = Integer.parseInt(paxInfo[1]);
                    passGender = Integer.parseInt(paxInfo[2]);
                    passFoodPref = paxInfo[3];

                    dbhandler.addPassengerInfo(new PassengerInfo(addSeat,
                            passName, passAge, passGender, passFoodPref));
                }

                else {
                    addSeat = String.valueOf(i + (char) (asciiA) + j);
                    passName = "NA";
                    passAge = 0;
                    passGender = -1;
                    passFoodPref = "NA";

                    dbhandler.addPassengerInfo(new PassengerInfo(addSeat,
                            passName, passAge, passGender, passFoodPref));
                }

            }
        }
        return null;
    }

    @Override
    protected void onPostExecute(Object result) {
        // Pass the result data back to the main activity
        MainActivity.this.data = result;

        if (MainActivity.this.progressDialog != null) {
            MainActivity.this.progressDialog.dismiss();
        }
    }
}

When I run this it show the following error in logcat,

01-23 21:29:06.206: E/AndroidRuntime(704): FATAL EXCEPTION: AsyncTask #1
01-23 21:29:06.206: E/AndroidRuntime(704): java.lang.RuntimeException: An error occured while executing doInBackground()

Please help !

FYI: Entire Logcat

01-23 21:53:15.807: E/AndroidRuntime(742):     at android.os.AsyncTask$3.done(AsyncTask.java:200)
01-23 21:53:15.807: E/AndroidRuntime(742):  at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274)
01-23 21:53:15.807: E/AndroidRuntime(742):  at java.util.concurrent.FutureTask.setException(FutureTask.java:125)
01-23 21:53:15.807: E/AndroidRuntime(742):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308)
01-23 21:53:15.807: E/AndroidRuntime(742):  at java.util.concurrent.FutureTask.run(FutureTask.java:138)
01-23 21:53:15.807: E/AndroidRuntime(742):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
01-23 21:53:15.807: E/AndroidRuntime(742):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
01-23 21:53:15.807: E/AndroidRuntime(742):  at java.lang.Thread.run(Thread.java:1019)
01-23 21:53:15.807: E/AndroidRuntime(742): Caused by: redis.clients.jedis.exceptions.JedisConnectionException: java.net.SocketTimeoutException: Connection timed out
01-23 21:53:15.807: E/AndroidRuntime(742):  at redis.clients.jedis.Connection.connect(Connection.java:134)
01-23 21:53:15.807: E/AndroidRuntime(742):  at redis.clients.jedis.BinaryClient.connect(BinaryClient.java:69)
01-23 21:53:15.807: E/AndroidRuntime(742):  at redis.clients.jedis.Connection.sendCommand(Connection.java:79)
01-23 21:53:15.807: E/AndroidRuntime(742):  at redis.clients.jedis.BinaryClient.hget(BinaryClient.java:212)
01-23 21:53:15.807: E/AndroidRuntime(742):  at redis.clients.jedis.Client.hget(Client.java:138)
01-23 21:53:15.807: E/AndroidRuntime(742):  at redis.clients.jedis.Jedis.hget(Jedis.java:680)
01-23 21:53:15.807: E/AndroidRuntime(742):  at android.jedisconnectiontest.com.MainActivity$DownloadTask.doInBackground(MainActivity.java:118)
01-23 21:53:15.807: E/AndroidRuntime(742):  at android.jedisconnectiontest.com.MainActivity$DownloadTask.doInBackground(MainActivity.java:1)
01-23 21:53:15.807: E/AndroidRuntime(742):  at android.os.AsyncTask$2.call(AsyncTask.java:185)
01-23 21:53:15.807: E/AndroidRuntime(742):  at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
01-23 21:53:15.807: E/AndroidRuntime(742):  ... 4 more
01-23 21:53:15.807: E/AndroidRuntime(742): Caused by: java.net.SocketTimeoutException: Connection timed out
01-23 21:53:15.807: E/AndroidRuntime(742):  at org.apache.harmony.luni.platform.OSNetworkSystem.connect(Native Method)
01-23 21:53:15.807: E/AndroidRuntime(742):  at dalvik.system.BlockGuard$WrappedNetworkSystem.connect(BlockGuard.java:357)
01-23 21:53:15.807: E/AndroidRuntime(742):  at org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:204)
01-23 21:53:15.807: E/AndroidRuntime(742):  at org.apache.harmony.luni.net.PlainSocketImpl.connect(PlainSocketImpl.java:437)
01-23 21:53:15.807: E/AndroidRuntime(742):  at java.net.Socket.connect(Socket.java:983)
01-23 21:53:15.807: E/AndroidRuntime(742):  at redis.clients.jedis.Connection.connect(Connection.java:129)
01-23 21:53:15.807: E/AndroidRuntime(742):  ... 13 more
01-23 21:53:17.737: E/WindowManager(742): Activity android.jedisconnectiontest.com.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@40523ac8 that was originally added here
01-23 21:53:17.737: E/WindowManager(742): android.view.WindowLeaked: Activity android.jedisconnectiontest.com.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@40523ac8 that was originally added here
01-23 21:53:17.737: E/WindowManager(742):   at android.view.ViewRoot.(ViewRoot.java:258)
01-23 21:53:17.737: E/WindowManager(742):   at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
01-23 21:53:17.737: E/WindowManager(742):   at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
01-23 21:53:17.737: E/WindowManager(742):   at android.view.Window$LocalWindowManager.addView(Window.java:424)
01-23 21:53:17.737: E/WindowManager(742):   at android.app.Dialog.show(Dialog.java:241)
01-23 21:53:17.737: E/WindowManager(742):   at android.app.ProgressDialog.show(ProgressDialog.java:107)
01-23 21:53:17.737: E/WindowManager(742):   at android.app.ProgressDialog.show(ProgressDialog.java:95)
01-23 21:53:17.737: E/WindowManager(742):   at android.jedisconnectiontest.com.MainActivity.onCreate(MainActivity.java:56)
01-23 21:53:17.737: E/WindowManager(742):   at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
01-23 21:53:17.737: E/WindowManager(742):   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
01-23 21:53:17.737: E/WindowManager(742):   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
01-23 21:53:17.737: E/WindowManager(742):   at android.app.ActivityThread.access$1500(ActivityThread.java:117)
01-23 21:53:17.737: E/WindowManager(742):   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:931)
01-23 21:53:17.737: E/WindowManager(742):   at android.os.Handler.dispatchMessage(Handler.java:99)
01-23 21:53:17.737: E/WindowManager(742):   at android.os.Looper.loop(Looper.java:123)
01-23 21:53:17.737: E/WindowManager(742):   at android.app.ActivityThread.main(ActivityThread.java:3683)
01-23 21:53:17.737: E/WindowManager(742):   at java.lang.reflect.Method.invokeNative(Native Method)
01-23 21:53:17.737: E/WindowManager(742):   at java.lang.reflect.Method.invoke(Method.java:507)
01-23 21:53:17.737: E/WindowManager(742):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
01-23 21:53:17.737: E/WindowManager(742):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
01-23 21:53:17.737: E/WindowManager(742):   at dalvik.system.NativeStart.main(Native Method)

Answer 1

Caused by: redis.clients.jedis.exceptions.JedisConnectionException: java.net.SocketTimeoutException: Connection timed out
Caused by: java.net.SocketTimeoutException: Connection timed out

This error means that the server did not answer between the given TimeOut value (normal about 10 seconds), is your server down? Or did you misspelled the server url?