You can't directly store  string in float. so you have to parse string  or convert
it into float.
see this method
parseFloat(String s)
this is of string class and return float  representation of the string you're
getting.

From JBuilder help

try {
f = Float.parseFloat(gg.trim());
}
catch (NumberFormatException e) {
...
}

where gg is your string  and f is your float.

you use static method 'parseFloat(String s)' from float  class to convert
string to float

float f = Float.parseFloat(stringFloat);

every basic type  has it's coresponding class in java that you can use to do
operations regarding to the type
int -> java.lang.Integer
float -> java.lang.Float
boolean -> java.lang.Boolean
.. etc

The return type  of request.getParameter("value") is string. Do typecasting to
convert into double value.

You have to explicitly convert the string  to a float. There are more than one
way
to do this but a good one is:

v_value = new Float(s_value).getValue(); // (instead of v_value = s_value;).