I am unable to connect JDBC to my database, getting following error
Error : E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.myprojectapplication, PID: 32686 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.myprojectapplication/com.example.myprojectapplication.MainActivity}: java.lang.UnsupportedOperationException at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) at android.app.ActivityThread.-wrap12(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:154) at android.app.ActivityThread.main(ActivityThread.java:6077) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756) Caused by: java.lang.UnsupportedOperationException at java.util.regex.Matcher.group(Matcher.java:383) at com.mysql.cj.conf.ConnectionUrlParser.isConnectionStringSupported(ConnectionUrlParser.java:152) at com.mysql.cj.conf.ConnectionUrl.acceptsUrl(ConnectionUrl.java:258) at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:187) at java.sql.DriverManager.getConnection(DriverManager.java:569) at java.sql.DriverManager.getConnection(DriverManager.java:219) at com.example.myprojectapplication.ObjectClass.JDBC.CONN(JDBC.java:19) at com.example.myprojectapplication.MainActivity.onCreate(MainActivity.java:72) at android.app.Activity.performCreate(Activity.java:6662) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2599) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) at android.app.ActivityThread.-wrap12(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:154) at android.app.ActivityThread.main(ActivityThread.java:6077) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)
package com.example.myprojectapplication.ObjectClass; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class JDBC { public void CONN() { Connection con = null; try { String url = "jdbc:mysql://localhost:3306/prog"; String username = "root"; String password = "mysql"; Class.forName("com.mysql.jdbc.Driver"); con = DriverManager.getConnection(url, username, password); if (con != null) { System.out .println("Successfully connected to MySQL database test"); } } catch (SQLException ex) { System.out .println("An error occurred while connecting MySQL databse"); ex.printStackTrace(); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (UnsupportedOperationException exa){ exa.printStackTrace(); } } }
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Answer
According to the stacktrace, the MySQL Connector/J version you are using is using a java.util.regex.Matcher
feature not supported on Android (probably named groups). The workaround is to use a 5.1.x version of MySQL Connector/J instead of a 8.0.x version.
However, you shouldn’t use JDBC from Android applications. It is insecure, and generally badly performing to connect to a database directly. The proper solution is to write a REST service (or other form of webservice) to mediate between your Android application and the database.