There are several places where you can select a character encoding from a list of the available character sets. The list of available character sets is determined by the Java Runtime Environment (JRE). Most of the time the JRE will have the character set you need. However, if you are using EBCDIC, the default character sets that come with the JRE do not include the EBCDIC character sets. There is no single character set for EBCDIC. Rather, there are EBCDIC character sets for different locales. For example, the English EBCDIC encoding is called IBM037 or CP037. When referencing the links below that describe the character sets, the EBCDIC character sets generally included in those are identified as IBM, but there are many IBM character sets on the list that are not actually EBCDIC.
If your character set is not present, it's likely part of the extended characters sets that are not automatically installed into your Java Runtime Environment (JRE). These links list the supported character sets for JRE 5 or JRE 6. To install the extended character set, get the charsets.jar file, which is an option in the Java installation, and place it in the lib directory of your JRE. See your system administrator if you need help with this.
If the character set is not present in any of the lists, then it is invalid and needs to changed to a value that is on the list.