Java tutorial
//package com.java2s; import java.lang.reflect.Field; public class Main { public static <T> void setFinalField(Class<T> clazz, T object, String fieldName, Object value) { try { Field headerField = clazz.getDeclaredField(fieldName); headerField.setAccessible(true); headerField.set(object, value); } catch (NoSuchFieldException e) { throw new RuntimeException(e); } catch (IllegalAccessException e2) { throw new RuntimeException(e2); } } }