javah: 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 Debian possible default full paths are:

/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/bin/javah - from package: gcj-4.8-jdk
/usr/lib/jvm/java-1.5.0-gcj-4.9-amd64/bin/javah - from package: gcj-4.9-jdk
/usr/lib/debug/usr/lib/jvm/java-7-openjdk-amd64/bin/javah - from package: openjdk-7-dbg
/usr/lib/jvm/java-7-openjdk-amd64/bin/javah - from package: openjdk-7-jdk

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

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