title: bin/java not found or not a valid JDK when installing SQLDeveloper 4 on Linux Mint
body: <p>I am trying to install sqldeveloper, and followed all the <a href="https://mikesmithers.wordpress.com/2014/03/26/installing-sqldeveloper-4-on-mint-and-ubuntu-minus-the-alien/" rel="nofollow">instructions</a> but no avail. Always getting the same error after running <code>./sqldeveloper.sh</code> and inserting <code>/usr/lib/jvm/java-7-oracle</code> as a path (Error: <code>/usr/lib/jvm/java-7-oracle/bin/java not found or not a valid JDK</code>). Any idea what might be going wrong? I would really appreciate any help or tip.</p>
  
  <p><code>echo $JAVA_HOME</code> returns this</p>
  
  <pre><code>/usr/lib/jvm/java-7-oracle
  </code></pre>
  
  <p><code>java -version</code>:</p>
  
  <pre><code>java version "1.7.0_80"
  Java(TM) SE Runtime Environment (build 1.7.0_80-b15)
  Java HotSpot(TM) 64-Bit Server VM (build 24.80-b11, mixed mode)
  </code></pre>
  
  <p><code>update-alternatives --config java</code>:</p>
  
  <pre><code>  0            /usr/lib/jvm/java-7-oracle/jre/bin/java          1072      auto mode
    1            /opt/java/jdk1.7.0_79/bin/java                   1         manual mode
    2            /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java   1071      manual mode
  * 3            /usr/lib/jvm/java-7-oracle/jre/bin/java          1072      manual mode
  </code></pre>
  
  <p>I have tried first choice too.</p>