I recently followed this tutorial on Google Cloud SQL and GWT: http://code.google.com/apis/sql/docs/developers_guide_java.html
I deployed this App to my google cloud sql server after having to create a GuestbookExample.gwt.xml file. I think i created it correctly:
<!-- Inherit the default GWT style sheet. You can change -->
<!-- the theme of your GWT application by uncommenting -->
<!-- any one of the following lines. -->
<inherits name='com.google.gwt.user.theme.clean.Clean'/>
<!-- <inherits name='com.google.gwt.user.theme.standard.Standard'/> -->
<!-- <inherits name='com.google.gwt.user.theme.chrome.Chrome'/> -->
<!-- <inherits name='com.google.gwt.user.theme.dark.Dark'/> -->
<!-- Other module inherits -->
<!-- Specify the app entry point class. -->
<!-- Specify the paths for translatable code -->
<source path='guestbook'/>
</module>
It was able to deploy to the server with no issues compiled from the GWT Compiler.
When I attempt to access the appspot site linked to my project I get the HTTP error:
Error: Server Error
The server encountered an error and could not complete your request.
If the problem persists, please report your problem and mention this error message and the query that caused it.
I thought this was strange so i checked the logs on the databse for Google Cloud SQL and I see the error as follows:
[02/Dec/2011:11:25:36 -0800] "GET / HTTP/1.1" 500 0 - "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:8.0) Gecko/20100101 Firefox/8.0" "cst433t1proj.appspot.com" ms=109 cpu_ms=175 api_cpu_ms=0 cpm_usd=0.004894 instance=00c61b117cb6def6096f8754a01131e49502
C 2011-12-02 11:25:36.913
Uncaught exception from servlet
java.lang.UnsupportedClassVersionError: guestbook/GuestbookServlet : Unsupported major.minor version 51.0
at com.google.appengine.runtime.Request.process-0000000000000000(Request.java)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:634)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
at org.mortbay.util.Loader.loadClass(Loader.java:91)
at org.mortbay.util.Loader.loadClass(Loader.java:71)
at org.mortbay.jetty.servlet.Holder.doStart(Holder.java:73)
at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:242)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:685)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:449)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:455)
at com.google.tracing.TraceContext.runInContext(TraceContext.java:695)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:333)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:325)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:453)
at java.lang.Thread.run(Thread.java:679)
What can i do to resolve this error? Im new at this database thing. Im just now learning GWT to assist in the creation of a final project. Any help would be appreciated.
You are probably using Java 7? The GAE has support for specific versions of Java check http://code.google.com/appengine/docs/java/overview.html and see if you are using the unsupported one.