How Can I create a generic HashMap to insert collections and objects?

Declare the hash map as

Map<String,Object> params = new HashMap<String,Object>();

You can keep the declaration of

public void method(Map<String, ?> params);

as it is, as long as the method only every tries to read from the map.

You need to change

Map<String,?>params=new HashMap<String,? > 

to like this

Map<String,Object>params=new HashMap<String,Object>()

But its not good practice to put all type of objects into single map. Better you can create POJO and add it to map.

All classes in Java extends Object. so you can use Object for a value type in a map, like

Map<String, Object> params = new HashMap<String, Object>