我正在编写一个需要登录和注册的应用程序，所以我在网上查找了一些教程。我还买了和在线托管服务器来存储我的数据库。但是，在运行应用程序时，我不断遇到运行时错误。我已经抓了一整天，仍然不知道这个问题。我很感激，如果有人能给我一些提示或线索，谢谢。
Log Cat错误
11-14 22:22:13.071: E/AndroidRuntime(12901): FATAL EXCEPTION: main
11-14 22:22:13.071: E/AndroidRuntime(12901): android.os.NetworkOnMainThreadException
11-14 22:22:13.071: E/AndroidRuntime(12901): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1118)
11-14 22:22:13.071: E/AndroidRuntime(12901): at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
11-14 22:22:13.071: E/AndroidRuntime(12901): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
11-14 22:22:13.071: E/AndroidRuntime(12901): at java.net.InetAddress.getAllByName(InetAddress.java:214)
11-14 22:22:13.071: E/AndroidRuntime(12901): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
11-14 22:22:13.071: E/AndroidRuntime(12901): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
11-14 22:22:13.071: E/AndroidRuntime(12901): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
11-14 22:22:13.071: E/AndroidRuntime(12901): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
11-14 22:22:13.071: E/AndroidRuntime(12901): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:670)
11-14 22:22:13.071: E/AndroidRuntime(12901): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:509)
11-14 22:22:13.071: E/AndroidRuntime(12901): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
11-14 22:22:13.071: E/AndroidRuntime(12901): at com.example.trafficmaster.library.JSONParser.getJSONFromUrl(JSONParser.java:42)
11-14 22:22:13.071: E/AndroidRuntime(12901): at com.example.trafficmaster.library.UserFunctions.registerUser(UserFunctions.java:61)
11-14 22:22:13.071: E/AndroidRuntime(12901): at com.example.trafficmaster.RegisterActivity$1.onClick(RegisterActivity.java:55)
11-14 22:22:13.071: E/AndroidRuntime(12901): at android.view.View.performClick(View.java:4211)
11-14 22:22:13.071: E/AndroidRuntime(12901): at android.view.View$PerformClick.run(View.java:17267)
11-14 22:22:13.071: E/AndroidRuntime(12901): at android.os.Handler.handleCallback(Handler.java:615)
11-14 22:22:13.071: E/AndroidRuntime(12901): at android.os.Handler.dispatchMessage(Handler.java:92)
11-14 22:22:13.071: E/AndroidRuntime(12901): at android.os.Looper.loop(Looper.java:137)
11-14 22:22:13.071: E/AndroidRuntime(12901): at android.app.ActivityThread.main(ActivityThread.java:4898)
11-14 22:22:13.071: E/AndroidRuntime(12901): at java.lang.reflect.Method.invokeNative(Native Method)
11-14 22:22:13.071: E/AndroidRuntime(12901): at java.lang.reflect.Method.invoke(Method.java:511)
11-14 22:22:13.071: E/AndroidRuntime(12901): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006)
11-14 22:22:13.071: E/AndroidRuntime(12901): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773)
11-14 22:22:13.071: E/AndroidRuntime(12901): at dalvik.system.NativeStart.main(Native Method)
11-14 22:22:18.251: D/dalvikvm(12901): GC_CONCURRENT freed 357K, 11% free 12504K/13895K, paused 4ms+9ms, total 46ms
11-14 22:22:25.251: I/Process(12901): Sending signal. PID: 12901 SIG: 9
我的注册主类
public class RegisterActivity extends Activity {
Button btnRegister;
Button btnLinkToLogin;
EditText inputFullName;
EditText inputEmail;
EditText inputPassword;
TextView registerErrorMsg;
// JSON Response node names
private static String KEY_SUCCESS = "success";
private static String KEY_ERROR = "error";
private static String KEY_ERROR_MSG = "error_msg";
private static String KEY_UID = "uid";
private static String KEY_NAME = "name";
private static String KEY_EMAIL = "email";
private static String KEY_CREATED_AT = "created_at";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.register);
// Importing all assets like buttons, text fields
inputFullName = (EditText) findViewById(R.id.registerName);
inputEmail = (EditText) findViewById(R.id.registerEmail);
inputPassword = (EditText) findViewById(R.id.registerPassword);
btnRegister = (Button) findViewById(R.id.btnRegister);
btnLinkToLogin = (Button) findViewById(R.id.btnLinkToLoginScreen);
registerErrorMsg = (TextView) findViewById(R.id.register_error);
// Register Button Click event
btnRegister.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
new MyInnerClass().execute();
String name = inputFullName.getText().toString();
String email = inputEmail.getText().toString();
String password = inputPassword.getText().toString();
UserFunctions userFunction = new UserFunctions();
JSONObject json = userFunction.registerUser(name, email, password);
// check for login response
try {
if (json.getString(KEY_SUCCESS) != null) {
registerErrorMsg.setText("");
String res = json.getString(KEY_SUCCESS);
if(Integer.parseInt(res) == 1){
// user successfully registred
// Store user details in SQLite Database
DatabaseHandler db = new DatabaseHandler(getApplicationContext());
JSONObject json_user = json.getJSONObject("user");
// Clear all previous data in database
userFunction.logoutUser(getApplicationContext());
db.addUser(json_user.getString(KEY_NAME), json_user.getString(KEY_EMAIL), json.getString(KEY_UID), json_user.getString(KEY_CREATED_AT));
// Launch Dashboard Screen
Intent dashboard = new Intent(getApplicationContext(), DashboardActivity.class);
// Close all views before launching Dashboard
dashboard.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(dashboard);
// Close Registration Screen
finish();
}else{
// Error in registration
registerErrorMsg.setText("Error occured in registration");
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}
});
答案 0 :(得分：3)
android.os.NetworkOnMainThreadException
从主线程访问网络时会发生此异常。使用AsyncTask来访问网络。
private class MyInnerClass extends AsyncTask<String, Void, String> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}
@Override
protected String doInBackground(String params) {
return "Done";
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
}
}
从您的主Activity调用new MyInnerClass().execute();，Android会自动调用onPreExecute()。此方法适用于您在网络访问之前所做的事情
网络相关内容在doInBackground()内完成，然后Android将调用onPostExecute()，结果将作为参数传递给此方法。
答案 1 :(得分：0)
您正在主线程上执行（可能很慢）网络操作。如果您的目标SDK是11（Honeycomb）或更高，这将在Honeycomb或更高版本上抛出NetworkOnMainThreadException，因为此行为可能会阻止UI并导致应用程序无响应。
您可以使用AsyncTask解决此问题，将数据加载到doInBackground(..)。