i make a plugin depend external library MySQL-connector but work only on running mode jar file don't work

Tools.java

package Actions;

import com.intellij.openapi.actionSystem.AnAction;
import com.intellij.openapi.actionSystem.AnActionEvent;

import com.intellij.openapi.project.Project;
import com.intellij.openapi.actionSystem.PlatformDataKeys;
import com.intellij.openapi.ui.Messages;

import java.sql.*;
import java.util.List;

/**
 * Created by aymen on 10/07/2017.
 */
public class Tools extends AnAction {

    @Override
    public void actionPerformed(AnActionEvent event) {


        Project project = event.getData(PlatformDataKeys.PROJECT);
        String txt = Messages.showInputDialog(project, "What is your name2?", "Input your name", Messages.getQuestionIcon());
        DBConnect dt = new DBConnect();
        List<String> result= dt.getTablesnames();
        String S = "";

        for (int i = 0; i < result.size(); i++)
            S = S + "\n" + result.get(i).toString();

       // System.out.println(S);
        Messages.showMessageDialog(project,  S, "Information", Messages.getInformationIcon());

    }

    }

DBConnect.java

package Actions;
/**
 * Created by aymen on 09/07/2017.
 */

import java.sql.*;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class DBConnect {

    // JDBC driver name and database URL
    static final String JDBC_DRIVER = "com.mysql.jdbc.Driver";
    static final String DB_URL = "jdbc:mysql://localhost/test";

    //  Database credentials
    static final String USER = "root";
    static final String PASS = "";

    public static void main(String[] args) {

    }

    public List<String> getTablesnames() {
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;
        List<String> result= new ArrayList<>();
        try {
            try {
                Class.forName("com.mysql.jdbc.Driver");
            } catch (ClassNotFoundException e) {
                result.add("aa"+e.toString());
                e.printStackTrace();
            }
            conn = DriverManager.getConnection(DB_URL, USER, PASS);

            DatabaseMetaData md = conn.getMetaData();

            rs = md.getTables(null, null, "%", null);
            while (rs.next()) {
                result.add(rs.getString("TABLE_NAME"));
            }
        } catch (SQLException e) {
            result.add("bb"+e.toString());

            e.printStackTrace();
        }
        return result;
    }
}

plugin.xml

<idea-plugin>
  <id>com.OPPa.generate.crud.android</id>
  <name>Plugin genrate crud</name>
  <version>1.0</version>
  <vendor email="aymenlabidi19@gmail.com" url="http://soffapp.tn">soffdevelopment</vendor>

  <description><![CDATA[
      Enter short qqsss description for your plugin here.<br>
      <em>most HTML tags may be used</em>
    ]]></description>

  <change-notes><![CDATA[
      Add change notes here.<br>
      <em>most HTML tags may be used</em>
    ]]>
  </change-notes>

  <!-- please see http://www.jetbrains.org/intellij/sdk/docs/basics/getting_started/build_number_ranges.html for description -->
  <idea-version since-build="145.0"/>

  <!-- please see http://www.jetbrains.org/intellij/sdk/docs/basics/getting_started/plugin_compatibility.html
       on how to target different products -->
  <!-- uncomment to enable plugin in all products
  <depends>com.intellij.modules.lang</depends>
  -->

  <extensions defaultExtensionNs="com.intellij">
    <!-- Add your extensions here -->
  </extensions>

  <actions>
    <!-- Add your actions here -->
    <action id="ToolsAction" class="Actions.Tools" text="Generate" description="generate crud  from database ">
      <add-to-group group-id="ToolsMenu" anchor="first"/>s
    </action>
  </actions>

</idea-plugin>

i got the error lang.Classnotfoundexception com.mysql.jdbc.driver Pluginclassloader