Unsupported major.minor version 51.0 (unable to load class org.postgresql.Driver)

Question

Created a web app using maven and deployed it on heroku. Everything works find but when I call a action that uses the postgresql-9.2-1002.jdbc4 driver I get:

java.lang.UnsupportedClassVersionError: org/postgresql/Driver : Unsupported major.minor version 51.0 (unable to load class org.postgresql.Driver) 

I know that the problem is I'm using jdk 7 on my development environment and a lower version is running on heroku (at least I think so). My first question is, why does the other actions don't give this error only actions that uses postqresql driver gives this problem the rest of the app works just fine? The other thing I did was download jdk 6 and then added it to my project build path, then configure eclipse compiler compliance to 1.6 but even then I have the same problem. How can I solve this?

Answer 1

For java 6 use:

postgresql-9.2-1004-jdbc4.jar  postgresql-9.3-1100-jdbc4.jar  

For java 7 use:

postgresql-9.2-1004-jdbc41.jar  postgresql-9.3-1100-jdbc41.jar