gson_get.java

  /**
	 * The following function does a top-down recursive decent on a json tree to
	 * find an element with-in structure
	 * 
	 * @param value -value to retrieve
	 * @param jObj -json object to traverse
	 * @param deep - deep traversal        
	 * @return JsonElement if found or null if element not found
	 */
	public JsonElement get(String value, JsonObject jObj, boolean deep) {

		// check current level for the key before descending
		if (jObj.isJsonObject() && jObj.has(value)) {
			// determines if a deep traversal should be done
			// if the value is not a primitive (which means it's an object)
			// continue traversing. if it is a primitive return that value
			if(deep) {
				if(jObj.isJsonPrimitive() || jObj.get(value).isJsonPrimitive())
					return jObj.get(value);
				return get(value, jObj.get(value).getAsJsonObject(), deep);
			} else return jObj.get(value);
		}

		// get all entry sets
		Set<Entry<String, JsonElement>> entries = jObj.entrySet();

		for (Entry<String, JsonElement> entry : entries) {

			// cache the current value since retrieval is done so much
			JsonElement curVal = entry.getValue();

			if (curVal.isJsonArray()) {
				for (JsonElement el : curVal.getAsJsonArray()) {
					// recursively traverse the sub-tree
					JsonElement res = get(value, el.getAsJsonObject(), deep);
					if (res != null)
						return res;
				}
			} else if (curVal.isJsonObject()) {
				// traverse sub-node
				return get(value, curVal.getAsJsonObject(), deep);
			}
		}
		
		// when a deep traversal is performed the function will recursively search until a matching key <K,V> is found
		// if the value is not a primitive type the iteration continues. 
		// if searched value is not a primitive and the function reaches the end of the recursion it will return the
		// bottom-most search level 
		// |-k---|
		// |--k--| << return this since the last level doesn't have the key
		// |-----|
		return deep ? jObj : null;
	}