ExtJoiner: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/ExtJoiner - from package: pki-java-tools

You may install the required package with command yum install {package}

Error in other languages:
ExtJoiner: bevel nie gevind nie
ExtJoiner: comandă negăsită
ExtJoiner: comando não encontrado
ExtJoiner: commande introuvable
ExtJoiner: command not found
ExtJoiner: käsku ei ole
ExtJoiner: không tìm thấy lệnh
ExtJoiner: komanda nerasta
ExtJoiner: Kommando nicht gefunden.
ExtJoiner: kommandot finns inte
ExtJoiner: komut yok
ExtJoiner: nie znaleziono polecenia
ExtJoiner: níor aimsíodh an t-ordú
ExtJoiner: no se encontró la orden
ExtJoiner: no s'ha trobat l'ordre
ExtJoiner: opdracht niet gevonden
ExtJoiner: parancs nem található
ExtJoiner: perintah tidak ditemukan
ExtJoiner: príkaz nenájdený
ExtJoiner: příkaz nenalezen
ExtJoiner: команда не найдена
ExtJoiner: командата не е открита
ExtJoiner: 命令找不到
ExtJoiner: コマンドが見つかりません