Donor does not define a no-argument constructor ?

Donor does not define a no-argument constructor. If you are using ProGuard, make sure these constructors are not stripped.

package com.example.blood_donor;

public class Donor {
    private final String name;
    private final String age;
    private final String mobile;
    private final String state;
    private final String city;
    private final String gender;
    private final String blood;
    private final String mail;
    private final String pin;

    public Donor(String name, String age, String mobile, String state, String city, String gender, String blood, String mail, String pin) {
        this.name = name;
        this.age = age;
        this.mobile = mobile;
        this.state = state;
        this.city = city;
        this.gender = gender;
        this.blood = blood;
        this.mail = mail;
        this.pin = pin; }
    public String getName() {
        return name;
    }
    public String getAge() {
        return age;
    }
    public String getMobile() {
        return mobile;
    }
    public String getState() {
        return state;
    }
    public String getCity() {
        return city;
    }
    public String getGender() {
        return gender;
    }
    public String getBlood() {
        return blood;
    }
    public String getMail() {
        return mail;
    }
    public String getPin() {
        return pin;
    }
}