title: how to make jni.h be found?
body: <p>In Ubuntu 12.04, I have jdk7 from sun/oracle installed. When <code>locate jni.h</code>, it prints multiple locations </p>
  
  <pre><code>/usr/lib/jvm/java-6-openjdk-amd64/include/jni.h
  /usr/lib/jvm/jdk1.7.0_07/include/jni.h
  ...
  </code></pre>
  
  <p>In the header file generated by JDK, there is <code>include &lt;jni.h&gt;</code>, and currently it complains </p>
  
  <pre><code>fatal error: jni.h: No such file or directory.
  </code></pre>
  
  <p>In my <code>Makefile</code>, there is no specification of locations where <code>jni.h</code> is. And I am asking if possible to configure certain system parameter to make path of <code>jni.h</code> (say, <code>/usr/lib/jvm/jdk1.7.0_07/include/jni.h</code>) to be known when being compiled.</p>