Spring 3.1 entityManagerFactory java.lang.NoSuchFieldError: NULL Error
This means there is a version mismatch--most likely with spring classes. So make sure all your spring jars are 3.1.0. Especially spring-expression. (Also upgrade your JPA provider (hibernate?) if it doesn't work after fixing spring)
It may help you.Upgrading from Spring 3.0.3.RELEASE results in: java.lang.NoSuchFieldError: USER_DECLARED_METHODS
Earlier I had like this
<dependencies><!-- Spring 3 dependencies --><dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>3.1.2.RELEASE</version></dependency>...</dependencies>Then I added
<dependencies><!-- Spring 3 dependencies --><dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>3.1.2.RELEASE</version> <exclusions> <exclusion> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> </exclusion> </exclusions></dependency>...</dependencies>