title: Java Exception java.lang.AbstractMethodError
body: <p>How can I solve this exception:</p>
  
  <pre><code>Exception in thread "main" java.lang.AbstractMethodError: com.mysql.jdbc.Connection.isValid(I)Z
      at org.apache.commons.dbcp2.DelegatingConnection.isValid(DelegatingConnection.java:914)
  ...
  </code></pre>
  
  <p>I read that this error is something about libraries/ jdk but I can't find a good way to solve it. I need some help from you. Thank you!</p>