javac command not working in linux environment

Question

I had successfully installed java on my linux system. When I ran a hello world test sample from desktop it ran successfully, but then after few days when I again tried to run it from terminal using javac command it gave me following response:

The program 'javac' can be found in the following packages:
 * default-jdk
 * ecj
 * gcj-5-jdk
 * openjdk-8-jdk-headless
 * gcj-4.8-jdk
 * gcj-4.9-jdk
 * openjdk-9-jdk-headless
Try: sudo apt install <selected package>

When I test my JAVA_HOME env. variable using echo $JAVA_HOME its showing: /usr/lib/jvm/java-8-openjdk-amd64

its also there with PATH variable. When I ran a which java command its showing: /usr/lib/jvm/java-8-openjdk-amd64/bin/java

and with command whereis java its showing: java: /usr/lib/jvm/java-8-openjdk-amd64/bin/java /usr/share/man/man1/java.1.gz

So, I don't understand the problem, as I, myself applied the env. variables, and its showing everything perfect, then why is not javac command running? can any one look into this problem.

Answer 1

dont worry here is your solution:) first, find where is JVM in your Linux

whereis jvm 

in my case jvm in jvm: /usr/lib/jvm so now go to that directory look at the image and checkout

after coming here

root㉿kali)-[/usr/lib/jvm/java-17-openjdk-amd64/bin]

search ls command look in the image there is not a javac file present

┌──(root㉿kali)-[/usr/lib/jvm/java-17-openjdk-amd64/bin]
└─# apt-get install openjdk-17-jdk

try this if you are using OpenJDK-8 or any different kindly changes the number as your requirement. this command download everything now look what new things come

┌──(root㉿kali)-[/usr/lib/jvm/java-17-openjdk-amd64/bin]
└─# ls                            
jar        javadoc   jdb        jhsdb   jmap      jrunscript  jstatd
jarsigner  javap     jdeprscan  jimage  jmod      jshell      keytool
java       jcmd      jdeps      jinfo   jpackage  jstack      rmiregistry
javac      jconsole  jfr        jlink   jps       jstat       serialver
                                                                           

hurray all stuff is done , learn how to run java in terminal, create hello.java file in desktop, let compile using javac , then run though java ,

┌──(root㉿kali)-[~/Desktop/javac]
└─# javac hello.java
Picked up _JAVA_OPTIONS: -Dawt.useSystemAAFontSettings=on -Dswing.aatext=true


                
                                                                                   
┌──(root㉿kali)-[~/Desktop/javac]
└─# java hello.java 
Picked up _JAVA_OPTIONS: -Dawt.useSystemAAFontSettings=on -Dswing.aatext=true
Hello World

Answer 2

Just my 5 cents. On CentOS 7 (assuming you want LTS Java 11):

sudo yum install java-11-openjdk-devel

Answer 3

The core problem is that you do not have the Java Develoment Toolkit (which is different than the Java runtime) installed on your system. This means that utilities used to create Java programs (such as javac, jar, etc) are not on your system.

Thorbjørn Ravn Andersen gave the answer for Debian-family Linux systems, here's the answer for RedHat-family systems

yum install java-devel

or if you are on the latest Fedora

dnf install java-devel

Answer 4

Undo your environment settings and run sudo apt install openjdk-8-jdk. javac should now be in your path.

Answer 5

/usr/lib/jvm/java-8-openjdk-amd64/bin/java

is not an dir, its an excecuteable. try excecute the following to use javac:

/usr/lib/jvm/java-8-openjdk-amd64/bin/javac

or

/usr/lib/jvm/java-8-openjdk-amd64/bin/jstack