在某些手机上存在连接错误

Question

我为android创建应用程序，并且我的应用程序连接到数据库。 连接到数据库时，不等待两个智能手机弹出。 最终测试的手机可以正常工作。两款手机都有版本 4.2.2 Android。

代码：

import android.annotation.SuppressLint;
import android.os.StrictMode;
import android.util.Log;


import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class Database {
    String ip,db,DBUserNameStr,DBPasswordStr;

    @SuppressLint("NewApi")
    public Connection connectionclasss()
    {

        // Declaring Server ip, username, database name and password
        ip = "123.123.123.123:20833";
        db = "top";
        DBUserNameStr = "userp";
        DBPasswordStr = "secret";
        // Declaring Server ip, username, database name and password


        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);
        java.sql.Connection connection = null;
        String ConnectionURL = null;
        try
        {

            Class.forName("net.sourceforge.jtds.jdbc.Driver");
            ConnectionURL = "jdbc:jtds:sqlserver://" + ip +";databaseName="+ db + ";user=" + DBUserNameStr+ ";password=" + DBPasswordStr + ";";
            connection = DriverManager.getConnection(ConnectionURL);
        }
        catch (SQLException se)
        {
            Log.e("error here 1 : ", se.getMessage());
        }
        catch (ClassNotFoundException e)
        {
            Log.e("error here 2 : ", e.getMessage());
        }
        catch (Exception e)
        {
            Log.e("error here 3 : ", e.getMessage());
        }
        return connection;
    }

}

应用程序在标尺上崩溃：

 connection = DriverManager.getConnection(ConnectionURL);

日志：

04-04 08:58:03.959 8401-8401/com.example.verdent E/error here 1 :: Network error IOException: failed to connect to /12.123.133.123(port 20833): connect failed: ENETUNREACH (Network is unreachable)

    --------- beginning of crash
04-04 08:58:03.965 8401-8401/com.example.verdent E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.verdent, PID: 8401
    java.lang.IllegalStateException: Could not execute method for android:onClick
        at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:389)
        at android.view.View.performClick(View.java:5280)
        at android.view.View$PerformClick.run(View.java:21768)
        at android.os.Handler.handleCallback(Handler.java:815)
        at android.os.Handler.dispatchMessage(Handler.java:104)
        at android.os.Looper.loop(Looper.java:207)
        at android.app.ActivityThread.main(ActivityThread.java:5917)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:888)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:749)
     Caused by: java.lang.reflect.InvocationTargetException
        at java.lang.reflect.Method.invoke(Native Method)
        at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:384)
        at android.view.View.performClick(View.java:5280) 
        at android.view.View$PerformClick.run(View.java:21768) 
        at android.os.Handler.handleCallback(Handler.java:815) 
        at android.os.Handler.dispatchMessage(Handler.java:104) 
        at android.os.Looper.loop(Looper.java:207) 
        at android.app.ActivityThread.main(ActivityThread.java:5917) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:888) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:749) 
     Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'java.sql.Statement java.sql.Connection.createStatement()' on a null object reference
        at com.example.verdent.MainActivity.ChcekDate(MainActivity.java:56)
        at com.example.verdent.MainActivity.DownloandData(MainActivity.java:43)
        at java.lang.reflect.Method.invoke(Native Method) 
        at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:384) 
        at android.view.View.performClick(View.java:5280) 
        at android.view.View$PerformClick.run(View.java:21768) 
        at android.os.Handler.handleCallback(Handler.java:815) 
        at android.os.Handler.dispatchMessage(Handler.java:104) 
        at android.os.Looper.loop(Looper.java:207) 
        at android.app.ActivityThread.main(ActivityThread.java:5917) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:888) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:749) 
04-04 08:58:03.970 1199-2287/? E/WindowManager: Unknown window type: 1000

有人知道为什么在这里关闭应用程序吗？