GWT is compiling your Java-Code to JavaScript and emulating the Classes and Methods you are using from the JRE. But GWT is not supporting all Classes and Methods of the JRE.
You can find a List of Supported Classes and Methods on gwtproject.org.
In your case java.util.Vector
is supported but not the methods add(float, float)
and set(float, float)
. So you should look for an alternative.
Note: The use of java.util.Vector
is not recommended - regardless of working with GWT or not.
Update: Can't remeber that there ever was a method add(float, float)
in java.util.Vector
. Do you use that class or do you have an own util.Vector
-Implementation?
If so you should check if your gwt.xml-file is including the source-path. Already explained here.