此应用程序可能在其主线程中做过多的工作

Question

i am using the following piece of code to add an item to mysql database.When the button is clicked,it should begin the Async task that uploads data to the server.But when i run it i get the error message "This application may be doing too much work in its main thread" from LogCat.How can i fix this code problem,thanks.

public class NewProductActivity extends Activity {

// Progress Dialog
private ProgressDialog pDialog;

JSONParser jsonParser = new JSONParser();
EditText inputName;
EditText inputPrice;
EditText inputDesc;

// url to create new product
private static String url_create_product = "http://localhost/android_connect/create_product.php";

// JSON Node names
private static final String TAG_SUCCESS = "success";

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.add_product);

    // Edit Text
    inputName = (EditText) findViewById(R.id.inputName);
    inputPrice = (EditText) findViewById(R.id.inputPrice);
    inputDesc = (EditText) findViewById(R.id.inputDesc);

    // Create button
    Button btnCreateProduct = (Button) findViewById(R.id.btnCreateProduct);

    // button click event
    btnCreateProduct.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View view) {
            // creating new product in background thread

            new CreateNewProduct().execute();

        }
    });
}

/**
 * Background Async Task to Create new product
 * */
class CreateNewProduct extends AsyncTask<String, String, String> {

    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(NewProductActivity.this);
        pDialog.setMessage("Creating Product..");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }

    /**
     * Creating product
     * */
    protected String doInBackground(String... args) {
        String name = inputName.getText().toString();
        String price = inputPrice.getText().toString();
        String description = inputDesc.getText().toString();

        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("name", name));
        params.add(new BasicNameValuePair("price", price));
        params.add(new BasicNameValuePair("description", description));

        // getting JSON Object
        // Note that create product url accepts POST method
        JSONObject json = jsonParser.makeHttpRequest(url_create_product,
                "POST", params);

        // check log cat fro response
        Log.d("Create Response", json.toString());

        // check for success tag
        try {
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {
                // successfully created product
                Intent i = new Intent(getApplicationContext(), AllProductsActivity.class);
                startActivity(i);

                // closing this screen
                finish();
            } else {
                // failed to create product
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }

this is the LogCat output:

05-08 12:51:26.761: I/Choreographer(762): Skipped 31 frames!  The application may be doing too much work on its main thread.
05-08 12:51:28.632: W/System.err(762): org.apache.http.conn.HttpHostConnectException: "Connection to localhost refused
05-08 12:51:28.672: W/System.err(762):  at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:183)
05-08 12:51:28.672: W/System.err(762):  at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
05-08 12:51:28.712: W/System.err(762):  at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
05-08 12:51:28.712: W/System.err(762):  at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
05-08 12:51:28.832: W/System.err(762):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
05-08 12:51:28.902: W/System.err(762):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
05-08 12:51:29.012: W/System.err(762):  at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
05-08 12:51:29.072: W/System.err(762):  at com.example.androidhive.JSONParser.makeHttpRequest(JSONParser.java:51)
05-08 12:51:29.072: W/System.err(762):  at com.example.androidhive.NewProductActivity$CreateNewProduct.doInBackground(NewProductActivity.java:97)
05-08 12:51:29.172: W/System.err(762):  at com.example.androidhive.NewProductActivity$CreateNewProduct.doInBackground(NewProductActivity.java:1)
05-08 12:51:29.252: W/System.err(762):  at android.os.AsyncTask$2.call(AsyncTask.java:287)
05-08 12:51:29.312: W/System.err(762):  at java.util.concurrent.FutureTask.run(FutureTask.java:234)
05-08 12:51:29.322: W/System.err(762):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
05-08 12:51:29.342: W/System.err(762):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
05-08 12:51:29.342: W/System.err(762):  at java.lang.Thread.run(Thread.java:856)
05-08 12:51:29.372: W/System.err(762): Caused by: java.net.ConnectException: failed to connect to /127.0.0.1 (port 80): connect failed: ECONNREFUSED (Connection refused)
05-08 12:51:29.442: W/System.err(762):  at libcore.io.IoBridge.connect(IoBridge.java:114)
05-08 12:51:29.493: W/System.err(762):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
05-08 12:51:29.552: W/System.err(762):  at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
05-08 12:51:29.552: W/System.err(762):  at java.net.Socket.connect(Socket.java:842)
05-08 12:51:29.572: W/System.err(762):  at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
05-08 12:51:29.652: W/System.err(762):  at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144)
05-08 12:51:29.692: W/System.err(762):  ... 14 more
05-08 12:51:29.763: W/System.err(762): Caused by: libcore.io.ErrnoException: connect failed: ECONNREFUSED (Connection refused)
05-08 12:51:29.872: W/System.err(762):  at libcore.io.Posix.connect(Native Method)
05-08 12:51:29.872: W/System.err(762):  at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:85)
05-08 12:51:29.892: W/System.err(762):  at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
05-08 12:51:29.992: W/System.err(762):  at libcore.io.IoBridge.connect(IoBridge.java:112)
05-08 12:51:29.992: W/System.err(762):  ... 19 more
05-08 12:51:30.102: E/Buffer Error(762): Error converting result java.lang.NullPointerException: lock == null
05-08 12:51:30.212: E/JSON Parser(762): Error parsing data org.json.JSONException: End of input at character 0 of 
05-08 12:51:30.302: W/dalvikvm(762): threadid=14: thread exiting with uncaught exception (group=0x40a71930)
05-08 12:51:30.602: E/AndroidRuntime(762): FATAL EXCEPTION: AsyncTask #4
05-08 12:51:30.602: E/AndroidRuntime(762): java.lang.RuntimeException: An error occured while executing doInBackground()
05-08 12:51:30.602: E/AndroidRuntime(762):  at android.os.AsyncTask$3.done(AsyncTask.java:299)
05-08 12:51:30.602: E/AndroidRuntime(762):  at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:352)
05-08 12:51:30.602: E/AndroidRuntime(762):  at java.util.concurrent.FutureTask.setException(FutureTask.java:219)
05-08 12:51:30.602: E/AndroidRuntime(762):  at java.util.concurrent.FutureTask.run(FutureTask.java:239)
05-08 12:51:30.602: E/AndroidRuntime(762):  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1080)
05-08 12:51:30.602: E/AndroidRuntime(762):  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:573)
05-08 12:51:30.602: E/AndroidRuntime(762):  at java.lang.Thread.run(Thread.java:856)
05-08 12:51:30.602: E/AndroidRuntime(762): Caused by: java.lang.NullPointerException
05-08 12:51:30.602: E/AndroidRuntime(762):  at com.example.androidhive.NewProductActivity$CreateNewProduct.doInBackground(NewProductActivity.java:101)    
05-08 12:51:30.602: E/AndroidRuntime(762):  at com.example.androidhive.NewProductActivity$CreateNewProduct.doInBackground(NewProductActivity.java:1)
05-08 12:51:30.602: E/AndroidRuntime(762):  at android.os.AsyncTask$2.call(AsyncTask.java:287)
05-08 12:51:30.602: E/AndroidRuntime(762):  at java.util.concurrent.FutureTask.run(FutureTask.java:234)
05-08 12:51:30.602: E/AndroidRuntime(762):  ... 3 more
05-08 12:51:32.542: I/Choreographer(762): Skipped 395 frames!  The application may be doing too much work on its main thread.
05-08 12:51:32.752: I/Choreographer(762): Skipped 54 frames!  The application may be doing too much work on its main thread.
05-08 12:51:33.892: I/Choreographer(762): Skipped 295 frames!  The application may be doing too much work on its main thread.
05-08 12:51:34.132: I/Choreographer(762): Skipped 58 frames!  The application may be doing too much work on its main thread.
05-08 12:51:35.762: E/WindowManager(762): Activity com.example.androidhive.NewProductActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{40d3d5e0 V.E..... R.....ID 0,0-329,175} that was originally added here
05-08 12:51:35.762: E/WindowManager(762): android.view.WindowLeaked: Activity com.example.androidhive.NewProductActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{40d3d5e0 V.E..... R.....ID 0,0-329,175} that was originally added here
05-08 12:51:35.762: E/WindowManager(762):   at android.view.ViewRootImpl.<init>(ViewRootImpl.java:354)
05-08 12:51:35.762: E/WindowManager(762):   at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:216)
05-08 12:51:35.762: E/WindowManager(762):   at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
05-08 12:51:35.762: E/WindowManager(762):   at android.app.Dialog.show(Dialog.java:281)
05-08 12:51:35.762: E/WindowManager(762):   at com.example.androidhive.NewProductActivity$CreateNewProduct.onPreExecute(NewProductActivity.java:78)
05-08 12:51:35.762: E/WindowManager(762):   at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:586)
05-08 12:51:35.762: E/WindowManager(762):   at android.os.AsyncTask.execute(AsyncTask.java:534)
05-08 12:51:35.762: E/WindowManager(762):   at com.example.androidhive.NewProductActivity$1.onClick(NewProductActivity.java:57)
05-08 12:51:35.762: E/WindowManager(762):   at android.view.View.performClick(View.java:4204)
05-08 12:51:35.762: E/WindowManager(762):   at android.view.View$PerformClick.run(View.java:17355)
05-08 12:51:35.762: E/WindowManager(762):   at android.os.Handler.handleCallback(Handler.java:725)
05-08 12:51:35.762: E/WindowManager(762):   at android.os.Handler.dispatchMessage(Handler.java:92)
05-08 12:51:35.762: E/WindowManager(762):   at android.os.Looper.loop(Looper.java:137)
05-08 12:51:35.762: E/WindowManager(762):   at android.app.ActivityThread.main(ActivityThread.java:5041)
05-08 12:51:35.762: E/WindowManager(762):   at java.lang.reflect.Method.invokeNative(Native Method)
05-08 12:51:35.762: E/WindowManager(762):   at java.lang.reflect.Method.invoke(Method.java:511)
05-08 12:51:35.762: E/WindowManager(762):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-08 12:51:35.762: E/WindowManager(762):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-08 12:51:35.762: E/WindowManager(762):   at dalvik.system.NativeStart.main(Native Method)
05-08 12:51:35.812: I/Choreographer(762): Skipped 172 frames!  The application may be doing too much work on its main thread.
05-08 12:51:36.172: I/Process(762): Sending signal. PID: 762 SIG: 9

Answer 1

Whilst it doesn't appear to be obviously related, in the logcat you post, the code is executing:

JSONObject json = jsonParser.makeHttpRequest(url_create_product,
            "POST", params);

when the code is terminated. It also appears that this request is failing ("unable to connect to localhost"). Could it be that when this request fails something else is getting onto the the UI thread somehow. Either way, this exception should probably be trapped and handled more cleanly.