Spring 3.1 web application issue

Question

I was developing a simple spring mvc application with one controller. when I deploy the war file, I get the following exception.

java.lang.IllegalAccessError: tried to access class org.springframework.core.convert.support.StringToBooleanConverter from class org.springframework.core.convert.support.DefaultConversionService at org.springframework.core.convert.support.DefaultConversionService.addScalarConverters(DefaultConversionService.java:61) at org.springframework.core.convert.support.DefaultConversionService.addDefaultConverters(DefaultConversionService.java:53) at org.springframework.core.convert.support.DefaultConversionService.<init>(DefaultConversionService.java:42) at org.springframework.core.env.AbstractPropertyResolver.<init>(AbstractPropertyResolver.java:44) at org.springframework.core.env.PropertySourcesPropertyResolver.<init>(PropertySourcesPropertyResolver.java:42) at org.springframework.core.env.AbstractEnvironment.<init>(AbstractEnvironment.java:95) at org.springframework.core.env.StandardEnvironment.<init>(StandardEnvironment.java:54) at org.springframework.web.context.support.StandardServletEnvironment.<init>(StandardServletEnvironment.java:43) at org.springframework.web.servlet.HttpServletBean.<init>(HttpServletBean.java:90) at org.springframework.web.servlet.FrameworkServlet.<init>(FrameworkServlet.java:211) at org.springframework.web.servlet.DispatcherServlet.<init>(DispatcherServlet.java:303) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) 

Answer 1

This sounds like a bootloader issue. I came across this before when I came across conflicts arising from loading MyEclipse of different jar files, and not those that I thought were downloaded by the application!

One way to check is to start Process Explorer and see the jar files that are loaded into memory and where they came from.

To get more specific error information you get, I quote the JVM 7 specification in which the exact error indicated is in 5.4. 3.1 :.

5.3. Create and Download

At run time, a class or interface is defined not only by its name, but also by a pair: its binary name (§4.2.1) and its defining class loader. Each such class or interface belongs to one run-time package. A class or interface runtime package is determined by the name of the package and the definition of the class or interface loader.

5.4.3.1. Class and Interface Resolution

To resolve an unresolved symbolic link from D to a class or interface C denoted by N, the following steps are performed:

The defining class loader D is used to create the class or interface designated N. This class or interface is C. Details of the process are given in clause 5.3.

Any exception that may be caused by a failure to create a class or interface may be thrown as a result of a denial of class and interface permission.

If C is an array class and its element type is a reference type, then a symbolic link to the class or interface representing the element type is resolved by recursively invoking the algorithm from clause 5.4.3.1.

Finally, access permissions for C are checked: If C is not available (§5.4.4) before D, the permission of the class or interface raises IllegalAccessError.

This condition may occur, for example, if C is a class that was originally declared public, but was changed to non-public after compiling D.

If steps 1 and 2 succeed, but step 3 fails, C is still valid and applicable. However, permission fails and D does not have access to C.

To summarize all this, it looks like the jar is from another package, that is, from another class loader.