com.foo.server.rpc230.OneFourTenSerializationPolicy.java Source code

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Here is the source code for com.foo.server.rpc230.OneFourTenSerializationPolicy.java

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/*
 * Copyright 2008 Jeff Dwyer
 * 
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package com.foo.server.rpc230;

import java.io.Serializable;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

import com.google.gwt.user.client.rpc.IsSerializable;
import com.google.gwt.user.client.rpc.SerializationException;
import com.google.gwt.user.server.rpc.SerializationPolicy;

class OneFourTenSerializationPolicy extends SerializationPolicy {

    /**
     * Many JRE types would appear to be {@link Serializable} on the server.
     * However, clients would not see these types as being {@link Serializable}
     * due to mismatches between the GWT JRE emulation and the real JRE. As a
     * workaround, this blacklist specifies a list of problematic types which
     * should be seen as not implementing {@link Serializable} for the purpose
     * matching the client's expectations. Note that a type on this list may
     * still be serializable via a custom serializer.
     */
    private static final Class[] JRE_BLACKLIST = { java.lang.ArrayStoreException.class,
            java.lang.AssertionError.class, java.lang.Boolean.class, java.lang.Byte.class,
            java.lang.Character.class, java.lang.Class.class, java.lang.ClassCastException.class,
            java.lang.Double.class, java.lang.Error.class, java.lang.Exception.class, java.lang.Float.class,
            java.lang.IllegalArgumentException.class, java.lang.IllegalStateException.class,
            java.lang.IndexOutOfBoundsException.class, java.lang.Integer.class, java.lang.Long.class,
            java.lang.NegativeArraySizeException.class, java.lang.NullPointerException.class,
            java.lang.Number.class, java.lang.NumberFormatException.class, java.lang.RuntimeException.class,
            java.lang.Short.class, java.lang.StackTraceElement.class, java.lang.String.class,
            java.lang.StringBuffer.class, java.lang.StringIndexOutOfBoundsException.class,
            java.lang.Throwable.class, java.lang.UnsupportedOperationException.class, java.util.ArrayList.class,
            java.util.ConcurrentModificationException.class, java.util.Date.class,
            java.util.EmptyStackException.class, java.util.EventObject.class, java.util.HashMap.class,
            java.util.HashSet.class, java.util.MissingResourceException.class,
            java.util.NoSuchElementException.class, java.util.Stack.class,
            java.util.TooManyListenersException.class, java.util.Vector.class, };

    private static final Set JRE_BLACKSET = new HashSet(Arrays.asList(JRE_BLACKLIST));

    private static final OneFourTenSerializationPolicy sInstance = new OneFourTenSerializationPolicy();

    public static OneFourTenSerializationPolicy getInstance() {
        return sInstance;
    }

    /**
     * Singleton.
     */
    private OneFourTenSerializationPolicy() {
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * com.google.gwt.user.server.rpc.SerializationPolicy#shouldDerializeFields
     * (java.lang.String)
     */
    public boolean shouldDeserializeFields(Class clazz) {
        return isFieldSerializable(clazz);
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * com.google.gwt.user.server.rpc.SerializationPolicy#shouldSerializeFields
     * (java.lang.String)
     */
    public boolean shouldSerializeFields(Class clazz) {
        return isFieldSerializable(clazz);
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * com.google.gwt.user.server.rpc.SerializationPolicy#validateDeserialize
     * (java.lang.String)
     */
    public void validateDeserialize(Class clazz) throws SerializationException {
        if (!isInstantiable(clazz)) {
            throw new SerializationException("Type '" + clazz.getName() + "' was not assignable to '"
                    + IsSerializable.class.getName()
                    + "' and did not have a custom field serializer.  For security purposes, this type will not be deserialized.");
        }
    }

    /*
     * (non-Javadoc)
     * 
     * @see
     * com.google.gwt.user.server.rpc.SerializationPolicy#validateSerialize(
     * java.lang.String)
     */
    public void validateSerialize(Class clazz) throws SerializationException {
        if (!isInstantiable(clazz)) {
            throw new SerializationException("Type '" + clazz.getName() + "' was not assignable to '"
                    + IsSerializable.class.getName()
                    + "' and did not have a custom field serializer.  For security purposes, this type will not be serialized.");
        }
    }

    /**
     * Field serializable types are primitives, {@line IsSerializable},
     * {@link Serializable}, types with custom serializers, and any arrays of
     * those types.
     */
    private boolean isFieldSerializable(Class clazz) {
        if (isInstantiable(clazz)) {
            return true;
        }
        if (Serializable.class.isAssignableFrom(clazz)) {
            return !JRE_BLACKSET.contains(clazz);
        }
        return false;
    }

    /**
     * Instantiable types are primitives, {@line IsSerializable}, types with
     * custom serializers, and any arrays of those types. Merely
     * {@link Serializable} types cannot be instantiated or serialized directly
     * (only as super types of legacy serializable types).
     */
    private boolean isInstantiable(Class clazz) {
        if (clazz.isPrimitive()) {
            return true;
        }
        if (clazz.isArray()) {
            return isInstantiable(clazz.getComponentType());
        }
        if (IsSerializable.class.isAssignableFrom(clazz)) {
            return true;
        }

        // NOTE this is the difference from Legacy
        if (Serializable.class.isAssignableFrom(clazz)) {
            return true;
        }

        return SerializabilityUtil.hasCustomFieldSerializer(clazz) != null;
    }

}