How to tell ProGuard to keep private fields without specifying each field

Question

This is my class:

package com.tools.app.holiday;

public class Holiday {  

    private String name;

    private Calendar dateFrom = Calendar.getInstance();         


        

Answer 1

According to ProGuard documenation the wildcard matches any field. Thus it should be something like:

-keepclassmembers class com.tools.app.holiday.Holiday {
    private ;    
}

If you want to preserve private fields in all classes use:

-keepclassmembers class * {
    private ;    
}