Error __java Gson object into Java complex object

There is a complex object data to be saved in the program, we turn this object into a string with Gson, and then deposit it directly into a CLOB field of the database as persistence. The next time you use, directly out, and then with the help of Gson into Java objects, for simple Java objects, Gson of the mutual turn is no problem. But my structure has a bit more nesting levels, and the Java data type is:

Map<string, Collection<linkedhashmap<string, string>>>

In use

New Gson (). Fromjson (Advdata.getdatastring (), map.class);

When you turn it into a Java object, you report:

Java.lang.ClassCastException:com.google.gson.internal.LinkedTreeMap cannot be cast to Java.util.HashMap

Google for a while, the user given the program is:

Map<string, collection<linkedhashmap<string, string>>> advdatamap = new Gson (). FromJson ( Advdata.getdatastring (), New typetoken<map<string, collection<linkedhashmap<string, String>>> > () {}.gettype ());