stringextractor: 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/share/doc/libhtmlparser-java-doc/examples/bin/stringextractor - from package: libhtmlparser-java-doc

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

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