问题
I'm developing with CodenameOne in the IntelliJ IDE. When I choose "Send MacOS Desktop Build", I get this error message:
Unsupported major.minor version 51.0
My project SDK says 1.5 (Java Version 1.6.0_65) My Language level is set to 5.0
I've done a rebuild, which should recompile everything, but I still get this error. Version 51 refers to Java 7. Can anyone tell me how to fix this?
回答1:
This is a problem because we require a minimum of JDK 1.7 and now recommend JDK 8. You need to set IntelliJ to use that JDK and configure it to use it.
回答2:
Does your project have any 3rd party cn1libs? It is possible some of them have been compiled with Java 7.
A workaround in that case would be to change your project to use Java 8. (I think that is supported in IntelliJ, but not 100% sure). For changing the project to Java 8 there are a few settings you need to change. It is usually just easier to start a new project and check "Java 8" in the wizard. Then copy your sources over.
回答3:
Please find the list of major minor version related issue.
J2SE 8 = 52,
J2SE 7 = 51,
J2SE 6.0 = 50,
J2SE 5.0 = 49,
JDK 1.4 = 48,
JDK 1.3 = 47,
JDK 1.2 = 46,
JDK 1.1 = 45
We can change the required compatible JDK Version from Configuration Page and it should work out.
回答4:
I had this issue while running cxf soap client.
Server: apache-tomcat-7.0.33
Error: java.lang.UnsupportedClassVersionError: org/apache/cxf/jaxws/JaxWsProxyFactoryBean : Unsupported major.minor version 51.0
Resolution: Resolved this by compiling the app using jdk1.8.0_65. Earlier i was using jdk1.7.
来源：https://stackoverflow.com/questions/34052428/unsupported-major-minor-version-51-0