JavaからMySQLにアクセスしようとしていますが、動作していません

Question

私はこのクラスを作成してMySQLデータベースからデータを取得していますが、毎回私はクラッシュするアプリを実行します。私のコード。私はこれに新しいですので、どんな助けも大歓迎です。

ここにエラーメッセージが表示されます。

04-15 18:46:58.058 15837-15837/com.example.tomb3.data E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.tomb3.data, PID: 15837 java.lang.NoClassDefFoundError: Failed resolution of: Ljunit/runner/Version; at com.example.tomb3.data.mySql.getData(mySql.java:37) at com.example.tomb3.data.MainActivity.onCreate(MainActivity.java:14) at android.app.Activity.performCreate(Activity.java:6237) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) at android.app.ActivityThread.-wrap11(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5417) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) Caused by: java.lang.ClassNotFoundException: Didn't find class "junit.runner.Version" on path: DexPathList[[zip file "/data/app/com.example.tomb3.data-1/base.apk"],nativeLibraryDirectories=[/data/app/com.example.tomb3.data-1/lib/x86, /vendor/lib, /system/lib]] at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56) at java.lang.ClassLoader.loadClass(ClassLoader.java:511) at java.lang.ClassLoader.loadClass(ClassLoader.java:469) at com.example.tomb3.data.mySql.getData(mySql.java:37)  at com.example.tomb3.data.MainActivity.onCreate(MainActivity.java:14)  at android.app.Activity.performCreate(Activity.java:6237)  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)  at android.app.ActivityThread.-wrap11(ActivityThread.java)  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)  at android.os.Handler.dispatchMessage(Handler.java:102)  at android.os.Looper.loop(Looper.java:148)  at android.app.ActivityThread.main(ActivityThread.java:5417)  at java.lang.reflect.Method.invoke(Native Method)  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)  Suppressed: java.lang.ClassNotFoundException: junit.runner.Version at java.lang.Class.classForName(Native Method) at java.lang.BootClassLoader.findClass(ClassLoader.java:781) at java.lang.BootClassLoader.loadClass(ClassLoader.java:841) at java.lang.ClassLoader.loadClass(ClassLoader.java:504) ... 15 more Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack trace available

public class mySql { 
    String url; 
    String user; 
    String password; 


    public mySql(String url, String user, String password){ 
     this.url=url; 
     this.user=user; 
     this.password=password; 
    } 
    public String getData(String table){ 
     Connection con = null; 
     Statement st = null; 
     ResultSet rs = null; 
     String output=""; 
     try { 
      con = DriverManager.getConnection(url, user, password); 
      st = con.createStatement(); 
      rs = st.executeQuery(table); 
      if (rs.next()) { 
       output += " " + (rs.getString(1)); 
      } 

     } catch (SQLException ex) { 
      Logger lgr = Logger.getLogger(Version.class.getName()); 
      lgr.log(Level.SEVERE, ex.getMessage(), ex); 
     } finally { 
      try { 
       if (rs != null) { 
        rs.close(); 
       } 
       if (st != null) { 
        st.close(); 
       } 
       if (con != null) { 
        con.close(); 
       } 

      } catch (SQLException ex) { 
       Logger lgr = Logger.getLogger(Version.class.getName()); 
       lgr.log(Level.WARNING, ex.getMessage(), ex); 
      } 
     } 
     return output; 
    } 
} 

Answer 1

ちょうど参照

import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.Statement; 

public class Main { 
    public static void main(String[] argv) throws Exception { 
    String driver = "com.mysql.jdbc.Driver"; 

    Class.forName(driver); 
    Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/dbname", "user", "password"); 

    Statement st = con.createStatement(); 
    int val = st.executeUpdate("INSERT employee VALUES(" + 13 + "," + "'Aman'" + ")"); 
    System.out.println("1 row affected"); 

    } 
} 

Answer 2

EXCEPTION: main Process: com.example.tomb3.data, PID: 15837 java.lang.NoClassDefFoundError: Failed resolution of: Ljunit/runner/Version;

のための何等のエラーメッセージ、スタックトレースを共有してください、あなたのクラスパスにJUnitの-xx.jar