<p>I've got a method JSNI that calls a Java method that take a Hasmap as input. 
I've tried </p>

<pre><code>handler.@com.mypackage::myMethod(Ljava/util/Hashmap;)(myHashMap);
handler.@com.mypackage::myMethod(Ljava/util/Hashmap&lt;Ljava/lang/String,Ljava/lang/String&gt;;)(myHashMap);
</code></pre>

<p>I'm can't seem to define the correct type signature to include the Strings or find if this usage is even allowed. </p>

<p>Since I'm doing this in gwt I though it might be the implementation of hashmap and the alternative approach I've though takes a String[][] array as input </p>

<p>I was hoping for somwthing like</p>

<p>handler.@com.mypackage::myMethod([[Ljava/lang/String;)(myArray);</p>

<p>However, I hit another issue of finding the correct JNSI sntax for the 2nd dimension of the array </p>

<p>A single dimension array ie. <code>[Ljava/lang/String;</code> is fine but I need the 2nd dimension.</p>

<p>Any help/ideas or links to good jnsi doc appreciated.</p>

Can you post the error that your getting, and also what kind of javascript object your trying to pass as a hashmap. I'm assuming you're getting a compile time error?
Here is a good start for JSNI documentation:
GWT JSNI doc
GWT Blog post on JSNI