如何处理没有互联网的AsyncTask？
如何处理没有互联网的AsyncTask？
提问于 2016-06-25 19:31:25
在我的登录页面上
当我按下按钮时，应用程序会在我离线时崩溃。怎么处理这个？
public class Login extends Activity{
EditText us,ps;
String sus,sps,sh1;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
us=(EditText)findViewById(R.id.username);
ps=(EditText)findViewById(R.id.password);
Button lgb=(Button)findViewById(R.id.button1);
lgb.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
sus=us.getText().toString();
sps=ps.getText().toString();
SharedPreferences shr=getSharedPreferences("kynum", MODE_WORLD_READABLE);
SharedPreferences.Editor edd=shr.edit();
edd.putString("sssnum", sus);
edd.commit();
if(sus.equals("")||sps.equals(""))
{
Toast.makeText(getApplicationContext(), "Field Vaccant", Toast.LENGTH_LONG).show();
return;
}
else
{
ilog lg =new ilog();
lg.execute();
}
}
});
}
public class ilog extends AsyncTask<Void, Void, Void>
{
@Override
protected Void doInBackground(Void... arg0) {
// TODO Auto-generated method stub
try
{
String server = getResources().getString(R.string.server_add);
DefaultHttpClient h=new DefaultHttpClient();
ResponseHandler<String> respp=new BasicResponseHandler();
HttpPost postMethod=new HttpPost(server+"ilogin.php");
List<NameValuePair>namevaluepairs=new ArrayList<NameValuePair>(2);
namevaluepairs.add(new BasicNameValuePair("Username", sus));
namevaluepairs.add(new BasicNameValuePair("Password", sps));
postMethod.setEntity(new UrlEncodedFormEntity(namevaluepairs));
sh1=h.execute(postMethod,respp);
}catch(Exception e)
{
System.out.println("Error:"+e);
}
return null;
}
@Override
protected void onPostExecute(Void result) {
// TODO Auto-generated method stub
if(sh1.contains("success"))
{
Toast.makeText(getApplicationContext(), "Successfully Logged in.", Toast.LENGTH_LONG).show();
Intent i=new Intent(getApplicationContext(), MainActivity.class);
startActivity(i);
}
else
{
Toast.makeText(getApplicationContext(), "Usernmae or Password error.", Toast.LENGTH_SHORT).show();
Toast.makeText(getApplicationContext(), "New User? Register First", Toast.LENGTH_LONG).show();
}
super.onPostExecute(result);
}
}
}我也在尽最大的努力来处理这件事，但是每次它坠毁，我的日志猫都是。
06-26 00:52:30.020: I/System.out(9732): Error:java.net.UnknownHostException: Unable to resolve host "equipz.orgfree.com": No address associated with hostname
06-26 00:52:30.020: W/System.err(9732): java.net.UnknownHostException: Unable to resolve host "equipz.orgfree.com": No address associated with hostname
06-26 00:52:30.022: W/System.err(9732): at java.net.InetAddress.lookupHostByName(InetAddress.java:457)
06-26 00:52:30.022: W/System.err(9732): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:252)
06-26 00:52:30.022: W/System.err(9732): at java.net.InetAddress.getAllByName(InetAddress.java:215)
06-26 00:52:30.022: W/System.err(9732): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:142)
06-26 00:52:30.022: W/System.err(9732): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:169)
06-26 00:52:30.022: W/System.err(9732): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:124)
06-26 00:52:30.022: W/System.err(9732): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:365)
06-26 00:52:30.022: W/System.err(9732): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:560)
06-26 00:52:30.022: W/System.err(9732): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:658)
06-26 00:52:30.023: W/System.err(9732): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:632)
06-26 00:52:30.023: W/System.err(9732): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:621)
06-26 00:52:30.023: W/System.err(9732): at com.hackbal.custmrmgmt.Login$ilog.doInBackground(Login.java:89)
06-26 00:52:30.023: W/System.err(9732): at com.hackbal.custmrmgmt.Login$ilog.doInBackground(Login.java:1)
06-26 00:52:30.023: W/System.err(9732): at android.os.AsyncTask$2.call(AsyncTask.java:292)
06-26 00:52:30.023: W/System.err(9732): at java.util.concurrent.FutureTask.run(FutureTask.java:237)
06-26 00:52:30.023: W/System.err(9732): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
06-26 00:52:30.023: W/System.err(9732): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
06-26 00:52:30.023: W/System.err(9732): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
06-26 00:52:30.023: W/System.err(9732): at java.lang.Thread.run(Thread.java:818)
06-26 00:52:30.023: W/System.err(9732): Caused by: android.system.GaiException: android_getaddrinfo failed: EAI_NODATA (No address associated with hostname)
06-26 00:52:30.023: W/System.err(9732): at libcore.io.Posix.android_getaddrinfo(Native Method)
06-26 00:52:30.023: W/System.err(9732): at libcore.io.ForwardingOs.android_getaddrinfo(ForwardingOs.java:55)
06-26 00:52:30.023: W/System.err(9732): at java.net.InetAddress.lookupHostByName(InetAddress.java:438)
06-26 00:52:30.023: W/System.err(9732): ... 18 more
06-26 00:52:30.044: E/AndroidRuntime(9732): FATAL EXCEPTION: AsyncTask #5
06-26 00:52:30.044: E/AndroidRuntime(9732): Process: com.hackbal.custmrmgmt, PID: 9732
06-26 00:52:30.044: E/AndroidRuntime(9732): java.lang.RuntimeException: An error occured while executing doInBackground()
06-26 00:52:30.044: E/AndroidRuntime(9732): at android.os.AsyncTask$3.done(AsyncTask.java:304)
06-26 00:52:30.044: E/AndroidRuntime(9732): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
06-26 00:52:30.044: E/AndroidRuntime(9732): at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
06-26 00:52:30.044: E/AndroidRuntime(9732): at java.util.concurrent.FutureTask.run(FutureTask.java:242)
06-26 00:52:30.044: E/AndroidRuntime(9732): at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
06-26 00:52:30.044: E/AndroidRuntime(9732): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
06-26 00:52:30.044: E/AndroidRuntime(9732): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
06-26 00:52:30.044: E/AndroidRuntime(9732): at java.lang.Thread.run(Thread.java:818)
06-26 00:52:30.044: E/AndroidRuntime(9732): Caused by: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
06-26 00:52:30.044: E/AndroidRuntime(9732): at android.os.Handler.<init>(Handler.java:200)
06-26 00:52:30.044: E/AndroidRuntime(9732): at android.os.Handler.<init>(Handler.java:114)
06-26 00:52:30.044: E/AndroidRuntime(9732): at android.widget.Toast$TN.<init>(Toast.java:344)
06-26 00:52:30.044: E/AndroidRuntime(9732): at android.widget.Toast.<init>(Toast.java:100)
06-26 00:52:30.044: E/AndroidRuntime(9732): at android.widget.Toast.makeText(Toast.java:258)
06-26 00:52:30.044: E/AndroidRuntime(9732): at com.hackbal.custmrmgmt.Login$ilog.doInBackground(Login.java:95)
06-26 00:52:30.044: E/AndroidRuntime(9732): at com.hackbal.custmrmgmt.Login$ilog.doInBackground(Login.java:1)
06-26 00:52:30.044: E/AndroidRuntime(9732): at android.os.AsyncTask$2.call(AsyncTask.java:292)
06-26 00:52:30.044: E/AndroidRuntime(9732): at java.util.concurrent.FutureTask.run(FutureTask.java:237)
06-26 00:52:30.044: E/AndroidRuntime(9732): ... 4 more
06-26 00:52:32.110: I/Process(9732): Sending signal. PID: 9732 SIG: 9我想给你看个祝酒词。什么是错误，如何消除？
回答 3
Stack Overflow用户
回答已采纳
发布于 2016-06-25 20:10:54
正如@Alex所说，您可以在尝试连接到服务器之前检查网络可用性。
例如，这里我检查了网络可用性，并显示了一个“没有连接”的snackbar
private boolean isNetworkAvailable() {
getActivity().runOnUiThread(new Runnable() {
public void run() {
// Update UI here when network is available.
ConnectivityManager connectivityManager
= (ConnectivityManager) getActivity().getSystemService(Context.CONNECTIVITY_SERVICE);
activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
if (!(activeNetworkInfo != null && activeNetworkInfo.isConnectedOrConnecting())) {
Snackbar snackbar = Snackbar
.make(coordinatorLayout, "No internet connection!", Snackbar.LENGTH_INDEFINITE)
.setAction("RETRY", new View.OnClickListener() {
@Override
public void onClick(View view) {
isNetworkAvailable();
}
});
View sbView = snackbar.getView();
snackbar.setActionTextColor(Color.WHITE);
sbView.setBackgroundColor(ContextCompat.getColor(getActivity(), R.color.snackbar_back_color2));
TextView textView = (TextView) sbView.findViewById(android.support.design.R.id.snackbar_text);
//textView.setTextColor(Color.YELLOW);
snackbar.show();
}
}
});
return (activeNetworkInfo != null && activeNetworkInfo.isConnectedOrConnecting());}
Stack Overflow用户
发布于 2016-06-25 19:46:36
您可以注册广播接收器，它侦听“更改网络状态”事件。如果在处理http请求时发生这种情况，请保存此事实，然后稍后再试。
Stack Overflow用户
发布于 2016-06-25 20:13:42
在我看来，您混淆了网络连接的日志消息和与崩溃相关的日志消息。
在DefaultHttpClient.execute失败后(这会引发仅通过在日志中打印处理的异常)，onPostExecute中的if语句将导致您在显示Toast时崩溃。
确保吐司是从正确的线程调用的，并使用正确的Context。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/38032227
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