java - 在Android中用java代码访问mysql

Question

在 Mysql 表中我有数据库:-

mysql> use student
mysql> select * from ari;
+----+-------+
| id | name  |
+----+-------+
| 22 | Sandy |
+----+-------+

我已经在我的电脑上安装了jetty和mysql，端口是:--

http://localhost(172.0.0.1):8080/
http://localhost(172.0.0.1):3306/

这是我的java代码:--(MainActivity.java)

  public class MainActivity extends Activity {
    private static final String url = "jdbc:mysql://localhost:3306/student";
    private static final String user = "root";
    private static final String pass = "root";
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        testDB();
    } 

    public void testDB() {
        TextView tv = (TextView)this.findViewById(R.id.textView1);

        try {

            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection(url, user, pass);
            String result = "Database connection success\n";
            Statement st = con.createStatement();
            ResultSet rs = st.executeQuery("select * from ari");
            ResultSetMetaData rsmd = rs.getMetaData();

            while(rs.next()) {
                            result += rsmd.getColumnName(1) + ": " + rs.getInt(1) + "\n";
                            result += rsmd.getColumnName(2) + ": " + rs.getString(2) + "\n";
                        }

            tv.setText(result);
               }
        catch(Exception e) {

                           e.printStackTrace();
                           tv.setText(e.toString());
        }   
    }
}

activity_main.xml 是:--

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin" >
    <TextView
         android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        />
</RelativeLayout>

在我的项目中，我还添加了mysql-connector-java-5.1.34.jar

但是当我运行时，它在我的 Android 设备(手机)中显示错误:--

   com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: 
 Could not create connection to database server

谁能告诉我问题出在哪里？？？？？？？？？？？？？？？

Answer 1

如果您在手机中运行应用程序，显然它需要连接到您的 PC 的 IP 地址。不是本地主机。并且您的电脑和手机需要处于同一网络。

例如jdbc:mysql://your-pc-ip-address:3306/student