Can you handle the submit form event with jquery in order to change the values sent to the server?

I have a server in java that receives an object with even other objects inside the object. I would like to know if it is possible to change the submit in such a way that it can change the structure allowing to place an object in json in the form:

{
    data1:"asdasda",
    data2:{
        data1:"dasdasd",
        data2:"asdasdasda",
        data3:"dasdasd"
    },
    data3:{
        data1:"asdasdas",
        data2:"asdasdasd",
        data3:"asdasdasd"
    }
}

The example is simple. but the object to be sent has many fields that it did not want to explain because this pattern follows. But if not clear. I can elaborate a clearer example of the object or structure.

The problem that on the server we receive an object this way. and the client has an html form. I wanted the form to contain the data but I could not.