@PostMapping(value = "/multiplyparams", consumes = {"application/x-www-form-urlencoded"}, produces = MediaType.APPLICATION_JSON_VALUE)
@CrossOrigin(origins = "http://localhost:3000")
public int MultiplyParams(int a, int b){
    calculatedValues.setA(a);
    calculatedValues.setB(b);

    System.out.println(calculatedValues.getA());
    System.out.println(calculatedValues.getB());

    return a * b;
}

CalculateNumbers() {
    console.log(this.state.a);
    console.log(this.state.b);

    axios({
        method: 'post',
        headers: {
            'Content-Type': 'application/x-www-form-urlencoded;charset=UTF-8'
        },
        url: 'http://localhost:8080/multiplyparams',
        data: {
            a: this.state.a,
            b: this.state.b
        }
    }).then(response => {
        console.log(response);
        console.log(response.data);
    }).catch(error => {
        console.log(error.message);
        console.log(error.response);
        console.log(error.response.data);
    });
}

constructor (props) {
    super(props);

    this.state = {
        a: 0,
        b: 0
    }

    this.SetA = this.SetA.bind(this);
    this.SetB = this.SetB.bind(this);
    this.CalculateNumbers =  this.CalculateNumbers.bind(this);
}