如何处理MongoDB超时异常

Question

package com.donateblood.blooddonation;

/**
 * Created by YouCaf Iqbal on 4/5/2016.
 */
import android.app.ProgressDialog;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.MongoClient;
import com.mongodb.MongoClientURI;
import butterknife.ButterKnife;
import butterknife.InjectView;
public class SignupActivity extends AppCompatActivity {
    private Spinner mySpinner; private String bloodgroup,name,password,number,location,email;
    @InjectView(R.id.input_name) EditText _nameText;
    @InjectView(R.id.input_email) EditText _emailText;
    @InjectView(R.id.input_password) EditText _passwordText;
    @InjectView(R.id.btn_signup) Button _signupButton;
    @InjectView(R.id.link_login) TextView _loginLink;
    @InjectView(R.id.input_location) TextView _locText;
    @InjectView(R.id.input_number) TextView _numText;
    DB db; boolean duplicate=false;
    DBCursor cursor;
    DBCollection collection;
    Database dbobj = new Database();

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_signup);
        Spinner spinner =(Spinner) findViewById(R.id.spinner);
        String[] list = getResources().getStringArray(R.array.blood_type);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,R.layout.spinner_layout,R.id.txt,list);
        spinner.setAdapter(adapter);
        ButterKnife.inject(this);
        _signupButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                signup();
            }
        });
        _loginLink.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // Finish the registration screen and return to the Login activity
                finish();
            }
        });
    }

    public void signup() {

        if (validate()==false) {
            onSignupFailed();
            return;
        }
        if(CheckEmailDuplicate()){
            Toast.makeText(getBaseContext(), "Account with this Email already exists", Toast.LENGTH_LONG).show();
            return;
        }
        _signupButton.setEnabled(false);
        dbAsync signupThread = new dbAsync();
        signupThread.execute();
    }

    public void onSignupSuccess() {

        _signupButton.setEnabled(true);
        setResult(RESULT_OK, null);
        Intent intent = new Intent(getApplicationContext(), LoginActivity.class);
        startActivity(intent);
        finish();
    }

    public void onSignupFailed() {
        Toast.makeText(getBaseContext(), "Sign Up failed", Toast.LENGTH_LONG).show();
        _signupButton.setEnabled(true);
    }

    public boolean validate() {
        boolean valid = true;
        GetUserDetails();
        if (name.isEmpty() || name.length() < 3) {
            _nameText.setError("at least 3 characters");
            valid = false;
        } else {
            _nameText.setError(null);
        }

        if (email.isEmpty() || !android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
            _emailText.setError("Enter a valid email address");
            valid = false;
        } else {
            _emailText.setError(null);
        }

        if (password.isEmpty() || password.length() < 4 || password.length() > 10) {
            _passwordText.setError("between 4 and 10 alphanumeric characters");
            valid = false;
        } else {
            _passwordText.setError(null);
        }

        if (location.isEmpty()) {
            _locText.setError("Enter location");
            valid = false;
        } else {
            _locText.setError(null);
        }
        if (number.isEmpty()) {
            _numText.setError("Enter valid number");
            valid = false;
        } else {
            _numText.setError(null);
        }

        return valid;
    }

    public class dbAsync extends AsyncTask<Void,Void,Void> {

        private ProgressDialog pDialog;
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(SignupActivity.this);
            pDialog.setMessage("Creating Account");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(true);
            pDialog.show();
        }
        @Override
        protected Void doInBackground(Void... voids) {
            GetUserDetails();
            dbobj.insertUser(name,email,password,location,number,bloodgroup);
            return null;
        }
        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);
            pDialog.dismiss();
            Toast.makeText(getBaseContext(), "Created Successfully", Toast.LENGTH_LONG).show();
            onSignupSuccess();
        }
    }

    public void GetUserDetails(){
        mySpinner=(Spinner) findViewById(R.id.spinner);
        bloodgroup = mySpinner.getSelectedItem().toString();
        name = _nameText.getText().toString();
        email = _emailText.getText().toString();
        password = _passwordText.getText().toString();
        location = _locText.getText().toString();
        number = _numText.getText().toString();
    }
    public boolean CheckEmailDuplicate(){

        email = _emailText.getText().toString();
        db = dbobj.getconnection();
        collection= db.getCollection("UserDetails");
        BasicDBObject query = new BasicDBObject();
        query.put("email", email);
        cursor = collection.find(query);
        if(cursor.hasNext()){
           duplicate=true;
        }
        return  duplicate;
    }
}

我不知道该怎么做。我是android开发新手，我使用mongodb作为我的数据库。我怎样才能解决这个超时问题以使我的代码正常工作。我尝试搜索此问题，但没有找到一个简单而好的描述性解决方案。帮助将不胜感激。提前谢谢。

Answer 1

错误是超时错误。如果您查看详细错误日志。

您获得异常未知主机名ds015730.mlab.com:15730

请timeout error错误hostname。请检查您的主机名。

  

当用户向服务器请求服务器时，会发生超时错误   在时间内没有响应，那个请求会导致超时错误。

在您的情况下，问题是由于错误的主机名。