此问题是由于 JSON 传递格式错误造成的.然后我改变了参数如下

This issue was happened because of wrong format of JSON passing. Then i changed the parameter as follows

let parameters = ["payment":["amount": "100" , "payment_method": "check", "date": "2015-11-25", "details": "Payment description dimuth Lasantha"]]

现在它传递了正确的格式

Now it passes the correct format which is

{
payment: {
    "amount" : "100",
    "payment_method" : "check",
     .....
    }
}