Migration Issue

In the weblogic.xml file there is a JSP parameter name called printNulls which can be set as follows.

<jsp-descriptor>
     <jsp-param>
          <jparam-name>
            printNulls
          </param-name>
          <param-value>
            <!-- set the value here to true or false -->
          </param-value>
     </jsp-param>
</jsp-descriptor>

(In WebLogic 9.2, the JSP parameter is print-nulls not printNulls )
printNulls provides a way to control whether a null value is converted to an empty string or "null" string in a response. If printNulls is set to true, then the null value is converted to a "null" string. If printNulls is false, then a null value is converted to an empty string instead of a "null" value. The default is true.

GlassFish currently does not provide a similar option. A null value will always be converted to a "null" string; the same as WebLogic Server's default. To convert a null value to an empty string, use the workaround described below.

Solution

The problem was encountered when using scriptlets. The workaround is therefore to use EL (Expression Language) instead of scriptlets, since EL returns "" instead of "null" for null Strings.