Main.java Source code

Introduction

Here is the source code for Main.java

Source

//package com.java2s;

import java.lang.reflect.Array;
import java.lang.reflect.Field;

public class Main {
    /**
     * Replace the value of a field containing a non null array, by a new array containing the elements of the original
     * array plus the elements of extraElements.
     *
     * @param instance the instance whose field is to be modified.
     * @param fieldName the field to modify.
     * @param extraElements elements to append at the end of the array.
     */
    static void expandFieldArray(Object instance, String fieldName, Object[] extraElements)
            throws NoSuchFieldException, IllegalArgumentException, IllegalAccessException {
        Field jlrField = findField(instance, fieldName);
        Object[] original = (Object[]) jlrField.get(instance);
        Object[] combined = (Object[]) Array.newInstance(original.getClass().getComponentType(),
                original.length + extraElements.length);
        System.arraycopy(extraElements, 0, combined, 0, extraElements.length);
        System.arraycopy(original, 0, combined, extraElements.length, original.length);
        jlrField.set(instance, combined);
    }

    /**
     * Locates a given field anywhere in the class inheritance hierarchy.
     *
     * @param instance an object to search the field into.
     * @param name field name
     * @return a field object
     * @throws NoSuchFieldException if the field cannot be located
     */
    static Field findField(Object instance, String name) throws NoSuchFieldException {
        for (Class<?> clazz = instance.getClass(); clazz != null; clazz = clazz.getSuperclass()) {
            try {
                Field field = clazz.getDeclaredField(name);

                if (!field.isAccessible()) {
                    field.setAccessible(true);
                }

                return field;
            } catch (NoSuchFieldException e) {
                // ignore and search next
            }
        }

        throw new NoSuchFieldException("Field " + name + " not found in " + instance.getClass());
    }
}