小白提问：在fragment里无法连接数据库！求解答

本人菜鸟，往大神们出招相助：
       本人写了一个链接mysql数据库的DButils类，在Activity中可以顺利链接，但在Fragment中就无法连接，调试显示连接为空。且显示((MySQLNonTransientConnectionException)e).SQLState=Cannot find local variable 'e'。代码如下，请帮忙呀！DButils类：package com.example.asus.wechat;import android.util.Log;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;/**
 * 数据库工具类：连接数据库用、获取数据库数据用
 * 相关操作数据库的方法均可写在该类
 */
public class DBUtils {    public static Connection connection=null;
    private static String driver = "com.mysql.jdbc.Driver";// MySql驱动
    private static PreparedStatement pds;    private static String user = "root";// 用户名
    private static String password = "888888";// 密码
    /**
     * 连接数据库
     * */    public static Connection getConn(String dbName){
        connection = null;
        try{
            Class.forName(driver);// 动态加载类
            String ip = "10.0.2.2";// 写成10.0.2.2，不能写成localhost，因为手机的IP是loaclhost
            // 尝试建立到给定数据库URL的连接
            connection = DriverManager.getConnection("jdbc:mysql://" + ip + ":3306/" + dbName+"?useUnicode=true&characterEncoding=UTF-8&useSSL=false&autoReconnect=true&failOverReadOnly=false",
                    user, password);
        }catch (Exception e){
            e.printStackTrace();
        }
        return connection;
    }    /**
     * 查询
     * */    public static HashMap<String, Object> getInfoByName(String name){        HashMap<String, Object> map = new HashMap<>();
        // 根据数据库名称，建立连接
        Connection connection = getConn("dblearner");        try {
            // mysql简单的查询语句。这里是根据MD_CHARGER表的NAME字段来查询某条记录
            String sql = "select * from uase where name = ?";
//            String sql = "select * from MD_CHARGER";
            if (connection != null){// connection不为null表示与数据库建立了连接
                PreparedStatement ps = connection.prepareStatement(sql);
                if (ps != null){
                    // 设置上面的sql语句中的？的值为name
                    ps.setString(1, name);
                    // 执行sql查询语句并返回结果集
                    ResultSet rs = ps.executeQuery();
                    if (rs != null){
                        int count = rs.getMetaData().getColumnCount();
                        Log.e("DBUtils","列总数：" + count);
                        while (rs.next()){
                            // 注意：下标是从1开始的
                            for (int i = 1;i <= count;i++){
                                String field = rs.getMetaData().getColumnName(i);
                                map.put(field, rs.getString(field));
                            }
                        }
                        connection.close();
                        ps.close();
                        return  map;
                    }else {
                        return null;
                    }
                }else {
                    return  null;
                }
            }else {
                return  null;
            }
        }catch (Exception e){
            e.printStackTrace();
            Log.e("DBUtils","异常：" + e.getMessage());
            return null;
        }    }}
fragment_11.javapackage com.example.asus.wechat;import android.annotation.SuppressLint;
import android.app.Person;
import android.content.Context;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;public class fragment_11 extends Fragment {    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";    private SimpleAdapter mAdpater;
    private Button btn_get_data;
    private TextView tv_data;
    private EditText editText;
    private Button ButAdd;
    private Button ButSelect;
    private EditText editid;
    private EditText editname;
    private EditText editpassword;
    private EditText editsex;
    private EditText editphote;
    private Button ButDel;
    private ListView lv;
    private Button ButQue;
    private Button ButNext;
    private List<Person> lists;
    private List<Map<String, Object>> data = new ArrayList<Map<String, Object>>();    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;    private OnFragmentInteractionListener mListener; 
    @SuppressLint("HandlerLeak")
    private Handler handler = new Handler(){
        @Override
        public void handleMessage(Message msg) {            switch (msg.what){
                case 0x11:
                    String s = (String) msg.obj;
                    tv_data.setText(s);
                    break;
                case 0x12:
                    String ss = (String) msg.obj;
                    tv_data.setText(ss);
                    break;
            }        }
    };    public fragment_11() {
        // Required empty public constructor
    }    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment fragment_11.
     */
    // TODO: Rename and change types and number of parameters
    public static fragment_11 newInstance(String param1, String param2) {
        fragment_11 fragment = new fragment_11();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_11, container, false);
        btn_get_data = view.findViewById(R.id.btn_get_data);
        tv_data =view. findViewById(R.id.tv_data);
        editText=view.findViewById(R.id.editText);        return view;
        //return inflater.inflate(R.layout.fragment_11, container, false);
    }    // TODO: Rename method, update argument and hook method into UI event
    public void onButtonPressed(Uri uri) {
        if (mListener != null) {
            mListener.onFragmentInteraction(uri);
        }
    }
    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     * <p>
     * See the Android Training lesson <a href=
     * "http://developer.android.com/training/basics/fragments/communicating.html"
     * >Communicating with Other Fragments</a> for more information.
     */
    public interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        void onFragmentInteraction(Uri uri);
    }    public void onActivityCreated(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onActivityCreated(savedInstanceState);
        btn_get_data.setOnClickListener(new View.OnClickListener() {            @Override
            public void onClick(View v) {                new Thread(new Runnable() {                    @Override
                    public void run() {                        HashMap<String, Object> map = DBUtils.getInfoByName(editText.getText().toString());
                        Message message = handler.obtainMessage();
                        if (map != null) {
                            String s = "";
                            for (String key : map.keySet()) {
                                s += key + ":" + map.get(key) + "\n";                            }
                            message.what = 0x12;
                            message.obj = s;
                        } else {
                            message.what = 0x11;
                            message.obj = "查询结果为空";
                        }
                        // 发消息通知主线程更新UI
                        handler.sendMessage(message);
                    }
                }).start();            }
        });    }
}