There is a small programming oversight in the wrap(...) function of org.hibernate.type.descriptor.java.BooleanTypeDescriptor.

Whenever an empty String is passed as the parameter, a _java.lang.StringIndexOutOfBoundsException_will be thrown in the following line:

return isTrue( ( (String) value ).charAt( 0 ) ) ? TRUE : FALSE;

This occurs because there is no test whether the string is empty (there is a test to see if it is null). It can easily be solved by adding that check.

In attachment there is simple PoC that triggers this problem.