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我正在開發一個android應用。我有一個包含多個元素的列表視圖。我使用php腳本從mysql數據庫中獲取列表中的元素。但在獲取項目時，我的應用程序崩潰並且登錄cat顯示以下錯誤。這裏有什麼問題？Android應用 - 網絡任務錯誤
這是我的logcat輸出。
12-22 16:03:30.440: D/dalvikvm(1431): GC_FOR_ALLOC freed 233K, 8% free 3989K/4296K, paused 85ms, total 99ms
12-22 16:03:32.070: I/Choreographer(1431): Skipped 219 frames! The application may be doing too much work on its main thread.
12-22 16:03:32.610: D/AndroidRuntime(1431): Shutting down VM
12-22 16:03:32.610: W/dalvikvm(1431): threadid=1: thread exiting with uncaught exception (group=0xb3a55ba8)
12-22 16:03:32.690: E/AndroidRuntime(1431): FATAL EXCEPTION: main
12-22 16:03:32.690: E/AndroidRuntime(1431): Process: com.example.orders, PID: 1431
12-22 16:03:32.690: E/AndroidRuntime(1431): android.os.NetworkOnMainThreadException
12-22 16:03:32.690: E/AndroidRuntime(1431): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1145)
12-22 16:03:32.690: E/AndroidRuntime(1431): at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)
12-22 16:03:32.690: E/AndroidRuntime(1431): at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
12-22 16:03:32.690: E/AndroidRuntime(1431): at libcore.io.IoBridge.connect(IoBridge.java:112)
12-22 16:03:32.690: E/AndroidRuntime(1431): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
12-22 16:03:32.690: E/AndroidRuntime(1431): at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:459)
12-22 16:03:32.690: E/AndroidRuntime(1431): at java.net.Socket.connect(Socket.java:843)
12-22 16:03:32.690: E/AndroidRuntime(1431): at org.apache.http.conn.scheme.PlainSocketFactory.connectSocket(PlainSocketFactory.java:119)
12-22 16:03:32.690: E/AndroidRuntime(1431): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:144)
12-22 16:03:32.690: E/AndroidRuntime(1431): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
12-22 16:03:32.690: E/AndroidRuntime(1431): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
12-22 16:03:32.690: E/AndroidRuntime(1431): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
12-22 16:03:32.690: E/AndroidRuntime(1431): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
12-22 16:03:32.690: E/AndroidRuntime(1431): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
12-22 16:03:32.690: E/AndroidRuntime(1431): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
12-22 16:03:32.690: E/AndroidRuntime(1431): at com.example.orders.JSONParser.makeHttpRequest(JSONParser.java:62)
12-22 16:03:32.690: E/AndroidRuntime(1431): at com.example.orders.EditProductActivity$GetProductDetails$1.run(EditProductActivity.java:132)
12-22 16:03:32.690: E/AndroidRuntime(1431): at android.os.Handler.handleCallback(Handler.java:733)
12-22 16:03:32.690: E/AndroidRuntime(1431): at android.os.Handler.dispatchMessage(Handler.java:95)
12-22 16:03:32.690: E/AndroidRuntime(1431): at android.os.Looper.loop(Looper.java:136)
12-22 16:03:32.690: E/AndroidRuntime(1431): at android.app.ActivityThread.main(ActivityThread.java:5001)
12-22 16:03:32.690: E/AndroidRuntime(1431): at java.lang.reflect.Method.invokeNative(Native Method)
12-22 16:03:32.690: E/AndroidRuntime(1431): at java.lang.reflect.Method.invoke(Method.java:515)
12-22 16:03:32.690: E/AndroidRuntime(1431): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
12-22 16:03:32.690: E/AndroidRuntime(1431): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
12-22 16:03:32.690: E/AndroidRuntime(1431): at dalvik.system.NativeStart.main(Native Method)
12-22 16:03:41.360: I/Process(1431): Sending signal. PID: 1431 SIG: 9
12-22 16:03:42.990: D/gralloc_goldfish(1457): Emulator without GPU emulation detected.
這裏是我的EditProductActivity
package com.example.orders;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
public class EditProductActivity extends Activity {
EditText txtName;
EditText txtPrice;
EditText txtDesc;
EditText txtCreatedAt;
Button btnSave;
Button btnDelete;
String pid;
// Progress Dialog
private ProgressDialog pDialog;
// JSON parser class
JSONParser jsonParser = new JSONParser();
// single product url
private static final String url_product_detials = "http://192.168.1.31/test/get_product_details.php";
// url to update product
private static final String url_update_product = "http://192.168.1.31/test/update_product.php";
// url to delete product
private static final String url_delete_product = "http://192.168.1.31/test/delete_product.php";
// JSON Node names
private static final String TAG_SUCCESS = "success";
private static final String TAG_PRODUCT = "product";
private static final String TAG_PID = "pid";
private static final String TAG_NAME = "name";
private static final String TAG_PRICE = "price";
private static final String TAG_DESCRIPTION = "description";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.edit_product);
// save button
btnSave = (Button) findViewById(R.id.btnSave);
btnDelete = (Button) findViewById(R.id.btnDelete);
// getting product details from intent
Intent i = getIntent();
// getting product id (pid) from intent
pid = i.getStringExtra(TAG_PID);
// Getting complete product details in background thread
new GetProductDetails().execute();
// save button click event
btnSave.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// starting background task to update product
new SaveProductDetails().execute();
}
});
// Delete button click event
btnDelete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
// deleting product in background thread
new DeleteProduct().execute();
}
});
}
/**
* Background Async Task to Get complete product details
* */
class GetProductDetails extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(EditProductActivity.this);
pDialog.setMessage("Loading product details. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
/**
* Getting product details in background thread
* */
protected String doInBackground(String... params) {
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
// Check for success tag
int success;
try {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("pid", pid));
// getting product details by making HTTP request
// Note that product details url will use GET request
JSONObject json = jsonParser.makeHttpRequest(
url_product_detials, "GET", params);
// check your log for json response
Log.d("Single Product Details", json.toString());
// json success tag
success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// successfully received product details
JSONArray productObj = json
.getJSONArray(TAG_PRODUCT); // JSON Array
// get first product object from JSON Array
JSONObject product = productObj.getJSONObject(0);
// product with this pid found
// Edit Text
txtName = (EditText) findViewById(R.id.inputName);
txtPrice = (EditText) findViewById(R.id.inputPrice);
txtDesc = (EditText) findViewById(R.id.inputDesc);
// display product data in EditText
txtName.setText(product.getString(TAG_NAME));
txtPrice.setText(product.getString(TAG_PRICE));
txtDesc.setText(product.getString(TAG_DESCRIPTION));
}else{
// product with pid not found
}
} catch (JSONException e) {
e.printStackTrace();
}
}
});
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog once got all details
pDialog.dismiss();
}
}
/**
* Background Async Task to Save product Details
* */
class SaveProductDetails extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(EditProductActivity.this);
pDialog.setMessage("Saving product ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
/**
* Saving product
* */
protected String doInBackground(String... args) {
// getting updated data from EditTexts
String name = txtName.getText().toString();
String price = txtPrice.getText().toString();
String description = txtDesc.getText().toString();
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair(TAG_PID, pid));
params.add(new BasicNameValuePair(TAG_NAME, name));
params.add(new BasicNameValuePair(TAG_PRICE, price));
params.add(new BasicNameValuePair(TAG_DESCRIPTION, description));
// sending modified data through http request
// Notice that update product url accepts POST method
JSONObject json = jsonParser.makeHttpRequest(url_update_product,
"POST", params);
// check json success tag
try {
int success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// successfully updated
Intent i = getIntent();
// send result code 100 to notify about product update
setResult(100, i);
finish();
} else {
// failed to update product
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog once product uupdated
pDialog.dismiss();
}
}
/*****************************************************************
* Background Async Task to Delete Product
* */
class DeleteProduct extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(EditProductActivity.this);
pDialog.setMessage("Deleting Product...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
/**
* Deleting product
* */
protected String doInBackground(String... args) {
// Check for success tag
int success;
try {
// Building Parameters
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("pid", pid));
// getting product details by making HTTP request
JSONObject json = jsonParser.makeHttpRequest(
url_delete_product, "POST", params);
// check your log for json response
Log.d("Delete Product", json.toString());
// json success tag
success = json.getInt(TAG_SUCCESS);
if (success == 1) {
// product successfully deleted
// notify previous activity by sending code 100
Intent i = getIntent();
// send result code 100 to notify about product deletion
setResult(100, i);
finish();
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog once product deleted
pDialog.dismiss();
}
}
}
網絡操作在裏面'doInBackground（）'爲什麼你在做'runOnUiThread（）''GetProductDetails'的AsyncTask？ –
@Nigam Patro我從後臺更新UI線程 – colombo