MySQL JDBC driver not working with GWT Eclipse Project

Question

My GWT application does not seem to find mysql-connector-java-5.1.22-bin.jar. Im using the Google App Engine.

I have set the jar in Project->RIghtClick->Properties->Java Build Path->Libraries->mysql-connector-java-5.1.22-bin.jar. I also added the "MySQL JDBC Driver". The $CLASSPATH is set correctly too (i dont think it matters because Im running the application in Eclipse).

I have tested the same code on command line and it works like a charm.

$ java -cp ~/mysql-connector-java-5.1.22/mysql-connector-java-5.1.22-bin.jar:. JDBCExample
-------- MySQL JDBC Connection Testing ------------
MySQL JDBC Driver Registered!
You made it, take control your database now!

When I run the Web Application in Eclipse, I get this

Exception:

-------- MySQL JDBC Connection Testing ------------
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
ClassNotFound - Where is your MySQL JDBC Driver?com.mysql.jdbc.Driver
    at java.net.URLClassLoader$1.run(URLClassLoader.java:366)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:355)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:354)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:423)
    at com.google.appengine.tools.development.IsolatedAppClassLoader.loadClass(IsolatedAppClassLoader.java:207)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:356)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:186)
    at com.startupweekend.server.GreetingServiceImpl.readDB(GreetingServiceImpl.java:65)
    at com.startupweekend.server.GreetingServiceImpl.greetServer(GreetingServiceImpl.java:21)

Code:

try {
  Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
  System.out.println("ClassNotFound - Where is your MySQL JDBC Driver?" + e.getMessage());              
  e.printStackTrace(); 
  return;
}

fernandohur fernandohur · Accepted Answer · 2012-12-03T02:56:09

I'm not completely sure, but you should just put the mysql driver in your WEB-INF/lib folder and then right click -> add to build path. That should make it work.

Bear in mind that in GAE you cannot use common relational databases, you can only use Google CloudSQL.

MySQL JDBC driver not working with GWT Eclipse Project

2 Answers