Unable to parse blank JSON String using GSON

Question

I am using gson to parse json data to model class but it throws errors as mentioned below. I referred some of the SO questions but am unable to solve the problem. I am using this link as reference.

Customer.class

public class Customer {

    private String Bank_Name;
    private String Bank_Bank;
    private String Bank_Account_Clabe;
    private String Bank_Accunt_Number;

    public String getBank_Name() {
        return Bank_Name;
    }

    public void setBank_Name(String bank_Name) {
        Bank_Name = bank_Name;
    }

    public String getBank_Bank() {
        return Bank_Bank;
    }

    public void setBank_Bank(String bank_Bank) {
        Bank_Bank = bank_Bank;
    }

    public String getBank_Account_Clabe() {
        return Bank_Account_Clabe;
    }

    public void setBank_Account_Clabe(String bank_Account_Clabe) {
        Bank_Account_Clabe = bank_Account_Clabe;
    }

    public String getBank_Accunt_Number() {
        return Bank_Accunt_Number;
    }

    public void setBank_Accunt_Number(String bank_Accunt_Number) {
        Bank_Accunt_Number = bank_Accunt_Number;
    }
}

Json Response

{
"Bank_Name": "",
"Bank_Bank": "",
"Bank_Account_Clabe": "",
"Bank_Accunt_Number": ""
}

error Log

System.err: com.google.gson.JsonSyntaxException: com.google.gson.stream.MalformedJsonException: Unexpected value at line 1 column 13 path $.Bank_Name

code

try {
GsonBuilder gb = new GsonBuilder();
Gson gson = gb.create();

Customer customer = gson.fromJson(s, Customer.class);
setData(customer);

} catch (Exception e) {

e.printStackTrace();
}