title: How to read meta data from Manifest file
body: <p>I'm trying to extract information from my manifest file to display in one of the methods in my <code>jar</code> file, but seem to be having some issues.  Any help is appreciated.</p>
  
  <p><strong>Manifest file:</strong></p>
  
  <pre><code>Manifest-Version: 1.0
  Created-By: 1.8.0_60 (Oracle Corporation)
  Main-Class: com.example.package1.myClass
  
  Name: com/example/package1
  Specification-Title: MyPackage
  Specification-Version: v1.1
  Specification-Vendor: MyCompanyName
  Implementation-Title: MP
  Implementation-Version: 2015-11-05-C
  Implementation-Vendor: MyName
  
  Name: com/example/package2
  Specification-Title: MySecondaryPackage
  Specification-Version: v2.0
  Specification-Vendor: MyCompanyName
  Implementation-Title: M2ndP
  Implementation-Version: 2015-11-05-C
  Implementation-Vendor: MyName
  </code></pre>
  
  <p><strong>myClass.java:</strong></p>
  
  <pre><code>package com.example.package1;
  import com.example.package2;
  
  class myClass {
    public static void main(String[] args) {
      try {
        myClass clz = new myClass();
        Thread.sleep(10000); //pause 10 seconnds so we can see what's spit out
      } catch (Exception e) {
      //excluded in example
      }
    }
  
    public myClass() {
      Package pkg = getClass().getPackage();
      if (pkg == null)
        System.out.println("No Package Found");
      else {
        System.out.println("specs: " + pkg.getSpecificationTitle() + " - " + pkg.getSpecificationVersion());
        System.out.println("imps:  " + pkg.getImplementationTitle() + " - " + pkg.getImplementationVersion());
        System.out.println("name:  " + pkg.getName());
      }
      //other code here excluded from example
    }
  }
  </code></pre>
  
  <p><strong>Output:</strong></p>
  
  <pre><code>specs: null - null
  imps:  null - null
  name:  com.example.package1
  </code></pre>
  
  <p>So what gives?  It looks like the pkg object is being defined correctly, but it doesn't read any of the Specification or Implementation properties.</p>