first add this dependency to pom.xml

<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>5.1.6</version>
</dependency>

and then use JDBC like below:

import java.sql.*;

public class JdbcReader implements Closeable{

    Connection conn;

    public JdbcReader() throws ClassNotFoundException, SQLException, IllegalAccessException, InstantiationException
    {
        // The newInstance() call is a work around for some
        // broken Java implementations
        Class.forName("com.mysql.jdbc.Driver").newInstance();
        this.conn = DriverManager.getConnection("jdbc:mysql://localhost/my_sample_db?user=guest");
    }

    /**
     * https://dev.mysql.com/doc/connector-j/en/connector-j-usagenotes-statements.html
     */
    public void test() throws Exception
    {
        Statement stmt = null;
        ResultSet rs = null;
        try {
            stmt = this.conn.createStatement();
            if (stmt.execute("SELECT * FROM my_sample_db.my_sample_table limit 20")) {
                rs = stmt.getResultSet();
                // Fetch each row from the result set
                while (rs.next()) {
                    String name = rs.getString("name");
                    String description = rs.getString("Descr");
                    System.out.printf("%s\t%s\n", name, description);
                }
            }
        }
        finally {
            // it is a good idea to release
            // resources in a finally{} block
            // in reverse-order of their creation
            // if they are no-longer needed

            if (rs != null) {
                try {
                    rs.close();
                } catch (SQLException sqlEx) { } // ignore

                rs = null;
            }

            if (stmt != null) {
                try {
                    stmt.close();
                } catch (SQLException sqlEx) { } // ignore

                stmt = null;
            }
        }
    }

    public void close()
    {
        if (conn != null)
        {
            try {
                conn.close();
            }
            catch (SQLException ex) { } // ignore
            conn = null;
        }
    }
}

Further Reading: https://docs.oracle.com/javase/tutorial/jdbc/index.html