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Vaadin 7 compatibility package for Vaadin 8
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/*
 * Copyright (C) 2000-2024 Vaadin Ltd
 *
 * This program is available under Vaadin Commercial License and Service Terms.
 *
 * See  for the full
 * license.
 */
package com.vaadin.v7.util;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

/**
 * Helper class for performing serialization. Most of the methods are here are
 * workarounds for problems in Google App Engine. Used internally by Vaadin and
 * should not be used by application developers. Subject to change at any time.
 *
 * @since 6.0
 * @deprecated Only used for compatibility-server
 */
@Deprecated
public class SerializerHelper {

    /**
     * Serializes the class reference so {@link #readClass(ObjectInputStream)}
     * can deserialize it. Supports null class references.
     *
     * @param out
     *            The {@link ObjectOutputStream} to serialize to.
     * @param cls
     *            A class or null.
     * @throws IOException
     *             Rethrows any IOExceptions from the ObjectOutputStream
     */
    public static void writeClass(ObjectOutputStream out, Class cls)
            throws IOException {
        if (cls == null) {
            out.writeObject(null);
        } else {
            out.writeObject(cls.getName());
        }

    }

    /**
     * Serializes the class references so
     * {@link #readClassArray(ObjectInputStream)} can deserialize it. Supports
     * null class arrays.
     *
     * @param out
     *            The {@link ObjectOutputStream} to serialize to.
     * @param classes
     *            An array containing class references or null.
     * @throws IOException
     *             Rethrows any IOExceptions from the ObjectOutputStream
     */
    public static void writeClassArray(ObjectOutputStream out,
            Class[] classes) throws IOException {
        if (classes == null) {
            out.writeObject(null);
        } else {
            String[] classNames = new String[classes.length];
            for (int i = 0; i < classes.length; i++) {
                classNames[i] = classes[i].getName();
            }
            out.writeObject(classNames);
        }
    }

    /**
     * Deserializes a class references serialized by
     * {@link #writeClassArray(ObjectOutputStream, Class[])}. Supports null
     * class arrays.
     *
     * @param in
     *            {@link ObjectInputStream} to read from.
     * @return Class array with the class references or null.
     * @throws ClassNotFoundException
     *             If one of the classes could not be resolved.
     * @throws IOException
     *             Rethrows IOExceptions from the ObjectInputStream
     */
    public static Class[] readClassArray(ObjectInputStream in)
            throws ClassNotFoundException, IOException {
        String[] classNames = (String[]) in.readObject();
        if (classNames == null) {
            return null;
        }
        Class[] classes = new Class[classNames.length];
        for (int i = 0; i < classNames.length; i++) {
            classes[i] = resolveClass(classNames[i]);
        }

        return classes;
    }

    /**
     * List of primitive classes. Google App Engine has problems
     * serializing/deserializing these (#3064).
     */
    private static final Class[] PRIMITIVE_CLASSES = {
            byte.class, short.class, int.class, long.class, float.class,
            double.class, boolean.class, char.class };

    /**
     * Resolves the class given by {@code className}.
     *
     * @param className
     *            The fully qualified class name.
     * @return A {@code Class} reference.
     * @throws ClassNotFoundException
     *             If the class could not be resolved.
     */
    public static Class resolveClass(String className)
            throws ClassNotFoundException {
        for (Class c : PRIMITIVE_CLASSES) {
            if (className.equals(c.getName())) {
                return c;
            }
        }

        return Class.forName(className);
    }

    /**
     * Deserializes a class reference serialized by
     * {@link #writeClass(ObjectOutputStream, Class)}. Supports null class
     * references.
     *
     * @param in
     *            {@code ObjectInputStream} to read from.
     * @return Class reference to the resolved class
     * @throws ClassNotFoundException
     *             If the class could not be resolved.
     * @throws IOException
     *             Rethrows IOExceptions from the ObjectInputStream
     */
    public static Class readClass(ObjectInputStream in)
            throws IOException, ClassNotFoundException {
        String className = (String) in.readObject();
        if (className == null) {
            return null;
        } else {
            return resolveClass(className);

        }

    }

    private SerializerHelper() {
    }

}