jhsearch: command not found

Have You tried accessing the binary with the full path?

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 Debian possible default full paths are:

/usr/bin/jhsearch - from package: javahelp2

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