Come sapere se la JDK è installata?

[e-commerce84]

Ciao,
scusate la domanda banale ma...come posso vedere se sul mio sistema la JDK è installata e correttamente attiva?

Grazie
Andrea

[wizard1993]

da terminale controlli se esiste javac con
which javac
se ti da un percorso ce l'hai, altrimenti no

[e-commerce84]

Originariamente inviato da wizard1993

da terminale controlli se esiste javac con
which javac
se ti da un percorso ce l'hai, altrimenti no

A me dice:

andrea@andrea-laptop:~$ javac
Usage: javac <options> <source files>
where possible options include:
  -g                         Generate all debugging info
  -g:none                    Generate no debugging info
  -g:{lines,vars,source}     Generate only some debugging info
  -nowarn                    Generate no warnings
  -verbose                   Output messages about what the compiler is doing
  -deprecation               Output source locations where deprecated APIs are used
  -classpath <path>          Specify where to find user class files and annotation processors
  -cp <path>                 Specify where to find user class files and annotation processors
  -sourcepath <path>         Specify where to find input source files
  -bootclasspath <path>      Override location of bootstrap class files
  -extdirs <dirs>            Override location of installed extensions
  -endorseddirs <dirs>       Override location of endorsed standards path
  -proc:{none,only}          Control whether annotation processing and/or compilation is done.
  -processor <class1>[,<class2>,<class3>...]Names of the annotation processors to run; bypasses default discovery process
  -processorpath <path>      Specify where to find annotation processors
  -d <directory>             Specify where to place generated class files
  -s <directory>             Specify where to place generated source files
  -implicit:{none,class}     Specify whether or not to generate class files for implicitly referenced files 
  -encoding <encoding>       Specify character encoding used by source files
  -source <release>          Provide source compatibility with specified release
  -target <release>          Generate class files for specific VM version
  -version                   Version information
  -help                      Print a synopsis of standard options
  -Akey[=value]              Options to pass to annotation processors
  -X                         Print a synopsis of nonstandard options
  -J<flag>                   Pass <flag> directly to the runtime system

Se nella shell lancio java -version mi dice:

andrea@andrea-laptop:~$ java -version
java version "1.6.0_24"
Java(TM) SE Runtime Environment (build 1.6.0_24-b07)
Java HotSpot(TM) 64-Bit Server VM (build 19.1-b02, mixed mode)
andrea@andrea-laptop:~$

[*andre*]

beh quindi il comando javac ce l'hai, quindi dovresti avere la jdk.
Fai un piccolo programma di prova e vedi subito

comunque wizard ti aveva detto di dare whitch javac, che ti stampa il percorso all'eseguibile.