javacc: 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/javacc - from package: javacc

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

On Debian possible default full paths are:

/usr/bin/javacc - from package: javacc

You may install the required package with command apt-get install {package}

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