title: javac command not working in linux environment
body: <p>I had successfully installed java on my <code>linux</code> 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 <code>javac</code> command it gave me following response:</p>
  
  <pre><code>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 &lt;selected package&gt;
  </code></pre>
  
  <p>When I test my <code>JAVA_HOME</code> env. variable using <code>echo $JAVA_HOME</code> its showing:
  <code>/usr/lib/jvm/java-8-openjdk-amd64</code></p>
  
  <p>its also there with <code>PATH</code> variable.
  When I ran a <code>which java</code> command its showing:
  <code>/usr/lib/jvm/java-8-openjdk-amd64/bin/java</code></p>
  
  <p>and with command <code>whereis java</code> its showing:
  <code>java: /usr/lib/jvm/java-8-openjdk-amd64/bin/java /usr/share/man/man1/java.1.gz</code></p>
  
  <p>So, I don't understand the problem, as I, myself applied the env. variables, and its showing everything perfect, then why is not <code>javac</code> command running? can any one look into this problem.</p>