This question already has answers here:
How to fix 'android.os.NetworkOnMainThreadException'?
（56个答案）
6年前关闭。
我开发了一个代码以使用android，Json ans Mysql登录，我的代码在模拟器（android 2.1）中工作，但在智能手机（4.1）中崩溃，这是日志猫中的错误
这是我的代码，如果有人可以帮助我更改某些内容，以允许我的应用程序运行到所有android版本中，请先感谢。
编辑：我在我的代码中做了一些更改（使用asyncTask），但是这次我的代码也无法正常工作，这是我所做的更改：
日志猫：
（56个答案）
6年前关闭。
我开发了一个代码以使用android，Json ans Mysql登录，我的代码在模拟器（android 2.1）中工作，但在智能手机（4.1）中崩溃，这是日志猫中的错误
error in http connection android.os.networkonmainthreadexception
这是我的代码，如果有人可以帮助我更改某些内容，以允许我的应用程序运行到所有android版本中，请先感谢。
public class ConnexionmysqlActivity extends Activity {
private static final String strURL = "http://mercure.comze.com/mercure/logi.php";
// private String result ;
private Button connexion ;
private EditText Logon ;
private EditText password ;
private JSONArray jArray;
private JSONObject json_data;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
Button connexion = (Button) findViewById(R.id.btn);
final EditText Logon = (EditText) findViewById(R.id.login);
final EditText password = (EditText) findViewById(R.id.mdpt);
connexion.setOnClickListener(new View.OnClickListener() {
@SuppressWarnings("unused")
public void onClick(View v) {
String result =null;
InputStream is = null;
StringBuilder sb = new StringBuilder();
ArrayList<NameValuePair> nameValuePairs=new ArrayList<NameValuePair> ();
nameValuePairs.add(new BasicNameValuePair("user",Logon.getText().toString()));
try{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(strURL);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
}catch(Exception e){
Log.e("log_tag", "Error in http connection " + e.toString());
}
try{
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result=sb.toString();
}catch(Exception e){
Log.e("log_tag", "Error in http connection " + e.toString());
}
String essai=result.substring(0, 4) ;
try {
if (result.matches("<br >")){
essai=result.substring(0, 2) ;
}
JSONArray jArray = new JSONArray(result);
int b=jArray.length();
JSONObject json_data = jArray.getJSONObject(0);
String mot_pass = json_data.getString("mdp").toString();
String login = json_data.getString("login").toString();
if (mot_pass.equals(password.getText().toString()) ){
Intent principale =new Intent(ConnexionmysqlActivity.this,compte.class);
principale.putExtra("login",login);
startActivity(principale);
}
else {
Toast.makeText(ConnexionmysqlActivity.this, "mot de pass invalide ", Toast.LENGTH_LONG).show();
}
}catch(JSONException e){
// Log.e("log_tag", "Error parsing data " + e.toString());
Toast.makeText(ConnexionmysqlActivity.this, "Utilisateur Inexistant ", Toast.LENGTH_LONG).show();
}
}
});
}
}
编辑：我在我的代码中做了一些更改（使用asyncTask），但是这次我的代码也无法正常工作，这是我所做的更改：
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
Button connexion = (Button) findViewById(R.id.btn);
final EditText Logon = (EditText) findViewById(R.id.login);
final EditText password = (EditText) findViewById(R.id.mdpt);
connexion.setOnClickListener(new View.OnClickListener() {
@SuppressWarnings("unused")
public void onClick(View v) {
new callServiceTask().execute();
}
});
}
class callServiceTask extends AsyncTask<Void, Void, Void>
{
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(ConnexionmysqlActivity.this);
pDialog.setMessage("Loading...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
// call web service
ArrayList<NameValuePair> nameValuePairs=new ArrayList<NameValuePair> ();
nameValuePairs.add(new BasicNameValuePair("user",Logon.getText().toString()));
try{
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost(strURL);
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
is = entity.getContent();
}catch(Exception e){
Log.e("log_tag", "Error in http connection " + e.toString());
}
try{
BufferedReader reader = new BufferedReader(new InputStreamReader(is,"iso-8859-1"),8);
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result=sb.toString();
}catch(Exception e){
Log.e("log_tag", "Error in http connection " + e.toString());
}
String essai=result.substring(0, 4) ;
try {
if (result.matches("<br >")){
essai=result.substring(0, 2) ;
}
JSONArray jArray = new JSONArray(result);
int b=jArray.length();
JSONObject json_data = jArray.getJSONObject(0);
String mot_pass = json_data.getString("mdp").toString();
String login = json_data.getString("login").toString();
if (mot_pass.equals(password.getText().toString()) ){
Intent principale =new Intent(ConnexionmysqlActivity.this,compte.class);
principale.putExtra("login",login);
startActivity(principale);
}
else {
Toast.makeText(ConnexionmysqlActivity.this, "mot de pass invalide ", Toast.LENGTH_LONG).show();
}
}catch(JSONException e){
// Log.e("log_tag", "Error parsing data " + e.toString());
Toast.makeText(ConnexionmysqlActivity.this, "Utilisateur Inexistant ", Toast.LENGTH_LONG).show();
}
return null;
}
@Override
protected void onPostExecute(Void resulta) {
//bind data in lisview or any other componet
pDialog.dismiss();
super.onPostExecute(resulta);
}
}
日志猫：
07-23 08:16:53.028: W/dalvikvm(15420): threadid=11: thread exiting with uncaught exception (group=0x2b542210)
07-23 08:16:53.048: E/AndroidRuntime(15420): FATAL EXCEPTION: AsyncTask #1
07-23 08:16:53.048: E/AndroidRuntime(15420): java.lang.RuntimeException: An error occured while executing doInBackground()
07-23 08:16:53.048: E/AndroidRuntime(15420): at android.os.AsyncTask$3.done(AsyncTask.java:278)
07-23 08:16:53.048: E/AndroidRuntime(15420): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:273)
07-23 08:16:53.048: E/AndroidRuntime(15420): at java.util.concurrent.FutureTask.setException(FutureTask.java:124)
07-23 08:16:53.048: E/AndroidRuntime(15420): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:307)
07-23 08:16:53.048: E/AndroidRuntime(15420): at java.util.concurrent.FutureTask.run(FutureTask.java:137)
07-23 08:16:53.048: E/AndroidRuntime(15420): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:208)
07-23 08:16:53.048: E/AndroidRuntime(15420): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1076)
07-23 08:16:53.048: E/AndroidRuntime(15420): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:569)
07-23 08:16:53.048: E/AndroidRuntime(15420): at java.lang.Thread.run(Thread.java:856)
07-23 08:16:53.048: E/AndroidRuntime(15420): Caused by: java.lang.NullPointerException
07-23 08:16:53.048: E/AndroidRuntime(15420): at com.project.mercureproject.ConnexionmysqlActivity$callServiceTask.doInBackground(ConnexionmysqlActivity.java:98)
07-23 08:16:53.048: E/AndroidRuntime(15420): at com.project.mercureproject.ConnexionmysqlActivity$callServiceTask.doInBackground(ConnexionmysqlActivity.java:1)
07-23 08:16:53.048: E/AndroidRuntime(15420): at android.os.AsyncTask$2.call(AsyncTask.java:264)
07-23 08:16:53.048: E/AndroidRuntime(15420): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:305)
07-23 08:16:53.048: E/AndroidRuntime(15420): ... 5 more
最佳答案
将此代码添加到oncreate方法中：
StrictMode.ThreadPolicy策略=新的StrictMode.ThreadPolicy.Builder（）。permitAll（）。build（）;
StrictMode.setThreadPolicy（policy）;
09-03 17:28