Well, having the action refer to the source code (ListAccounts.java) is certainly wrong. Your URL should point to something which your web.xml is configured to map to the compiled version of that servlet.
And having "/src/" in that URL is quite likely wrong. It's possible your IDE contains a "src" directory which contains your source code, but that has basically nothing to do with your deployed application. And if it is, that implies that your ListAccounts servlet isn't in any package, which is also wrong.