Unsupported major.minor version 51.0

[albertvalles2-zz]

Hi,

We are having issues running an old tomcat with jdk 6.

Caused by: java.lang.UnsupportedClassVersionError: com/matthewcasperson/validation/filter/ParameterValidationFilter : Unsupported major.minor version 51.0 (unable to load class com.matthewcasperson.validation.filter.ParameterValidationFilter) at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2893) at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1170) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1678) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1556) at org.apache.catalina.startup.WebAnnotationSet.loadClass(WebAnnotationSet.java:480) at org.apache.catalina.startup.WebAnnotationSet.loadApplicationFilterAnnotations(WebAnnotationSet.java:101) at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:65) at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:381) at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:858) at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:345) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5161) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ... 11 more

We tried compiling source code with java 6 but still having problems with signing plugin and some other compile errors:

warning: javax\servlet\Filter.class(javax\servlet:Filter.class): major version 51 is newer than 50, the highest major version supported by this compiler. It is recommended that the compiler be upgraded. warning: javax\servlet\FilterChain.class(javax\servlet:FilterChain.class): major version 51 is newer than 50, the highest major version supported by this compiler. It is recommended that the compiler be upgraded. warning: javax\servlet\FilterConfig.class(javax\servlet:FilterConfig.class): major version 51 is newer than 50, the highest major version supported by this compiler. It is recommended that the compiler be upgraded. warning: javax\servlet\ServletException.class(javax\servlet:ServletException.class): major version 51 is newer than 50, the highest major version supported by this compiler. It is recommended that the compiler be upgraded. warning: javax\servlet\ServletRequest.class(javax\servlet:ServletRequest.class): major version 51 is newer than 50, the highest major version supported by this compiler. It is recommended that the compiler be upgraded. warning: javax\servlet\ServletResponse.class(javax\servlet:ServletResponse.class): major version 51 is newer than 50, the highest major version supported by this compiler. It is recommended that the compiler be upgraded. warning: javax\servlet\http\HttpServletRequest.class(javax\servlet\http:HttpServletRequest.class): major version 51 is newer than 50, the highest major version supported by this compiler. It is recommended that the compiler be upgraded. warning: javax\servlet\http\HttpServletResponse.class(javax\servlet\http:HttpServletResponse.class): major version 51 is newer than 50, the highest major version supported by this compiler. It is recommended that the compiler be upgraded. C:\Users\...\Documents\git\ParameterValidationFilter\src\main\java\com\matthewcasperson\validation\filter\ParameterValidationFilter.java:53: cannot access com.google.common.base.Preconditions bad class file: com\google\common\base\Preconditions.class(com\google\common\base:Preconditions.class) class file has wrong version 52.0, should be 50.0 Please remove or make sure it appears in the correct subdirectory of the classpath. import static com.google.common.base.Preconditions.checkState; ^ :compileJava FAILED

downgrading to guavaVersion = '12.0' still produces compile errors like import static com.google.common.base.Preconditions.checkState;
......

Is it possible to do what we aim? Any suggestions?

thanks in advance!