As an example, if JSP is called with Korean character parameter in form data without encoding as below:
curl -v -X POST '127.0.0.1:8080/jsp-form-data-encoding/test.jsp' --data $'PARAM1=테스트한글'

• JBoss EAP 6.4.x encodes and prints the Korean character parameter successfully.

  13:40:11,172 INFO  [stdout] (http-127.0.0.1:8080-1) REQEUST CHARSET ENCODING: UTF-8
  13:40:11,173 INFO  [stdout] (http-127.0.0.1:8080-1) 한글테스트
  13:40:11,173 INFO  [stdout] (http-127.0.0.1:8080-1) -------------------------------------------
  13:40:11,173 INFO  [stdout] (http-127.0.0.1:8080-1) ============ Headers
  13:40:11,174 INFO  [stdout] (http-127.0.0.1:8080-1) ===== Header:host
  13:40:11,175 INFO  [stdout] (http-127.0.0.1:8080-1) 127.0.0.1:8080
  13:40:11,175 INFO  [stdout] (http-127.0.0.1:8080-1) ===== Header:user-agent
  13:40:11,175 INFO  [stdout] (http-127.0.0.1:8080-1) curl/7.53.1
  13:40:11,175 INFO  [stdout] (http-127.0.0.1:8080-1) ===== Header:accept
  13:40:11,178 INFO  [stdout] (http-127.0.0.1:8080-1) */*
  13:40:11,178 INFO  [stdout] (http-127.0.0.1:8080-1) ===== Header:content-length
  13:40:11,179 INFO  [stdout] (http-127.0.0.1:8080-1) 22
  13:40:11,179 INFO  [stdout] (http-127.0.0.1:8080-1) ===== Header:content-type
  13:40:11,179 INFO  [stdout] (http-127.0.0.1:8080-1) application/x-www-form-urlencoded
  13:40:11,179 INFO  [stdout] (http-127.0.0.1:8080-1) ============ Attributes
  13:40:11,180 INFO  [stdout] (http-127.0.0.1:8080-1) ============ Parameters
  13:40:11,180 INFO  [stdout] (http-127.0.0.1:8080-1) ===== Value:PARAM1
  13:40:11,180 INFO  [stdout] (http-127.0.0.1:8080-1) 테스트한글
  13:40:11,181 INFO  [stdout] (http-127.0.0.1:8080-1) decode:테스트한글
  

• However, the Korean character parameter is broken in JBoss EAP 7.x.

  13:39:18,987 INFO  [stdout] (default task-1) REQEUST CHARSET ENCODING: UTF-8
  13:39:18,988 INFO  [stdout] (default task-1) 한글테스트
  13:39:18,989 INFO  [stdout] (default task-1) -------------------------------------------
  13:39:18,989 INFO  [stdout] (default task-1) ============ Headers
  13:39:18,989 INFO  [stdout] (default task-1) ===== Header:Accept
  13:39:18,990 INFO  [stdout] (default task-1) */*
  13:39:18,990 INFO  [stdout] (default task-1) ===== Header:User-Agent
  13:39:18,990 INFO  [stdout] (default task-1) curl/7.53.1
  13:39:18,990 INFO  [stdout] (default task-1) ===== Header:Host
  13:39:18,990 INFO  [stdout] (default task-1) 127.0.0.1:8080
  13:39:18,990 INFO  [stdout] (default task-1) ===== Header:Content-Length
  13:39:18,991 INFO  [stdout] (default task-1) 22
  13:39:18,991 INFO  [stdout] (default task-1) ===== Header:Content-Type
  13:39:18,991 INFO  [stdout] (default task-1) application/x-www-form-urlencoded
  13:39:18,991 INFO  [stdout] (default task-1) ============ Attributes
  13:39:18,991 INFO  [stdout] (default task-1) ============ Parameters
  13:39:18,992 INFO  [stdout] (default task-1) ===== Value:PARAM1
  13:39:18,992 INFO  [stdout] (default task-1) ￭ﾅﾌ￬ﾊﾤ￭ﾊﾸ￭ﾕﾜ￪ﾸﾀ
  13:39:18,992 INFO  [stdout] (default task-1) decode:￭ﾅﾌ￬ﾊﾤ￭ﾊﾸ￭ﾕﾜ￪ﾸﾀ
  

Obviously, if a client sends the parameter with url encoding option like --data-urlencode or encoded parameter, it will work. However, it should work without the option or client encoding as EAP 6.4.x for better compatibility.
curl -v -X POST '127.0.0.1:8080/jsp-form-data-encoding/test.jsp' --data-urlencode $'PARAM1=테스트한글'

It can be reproduced by the attached war