GridPeerDeployAwareAdapter.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 org.apache.ignite.internal.util.lang;

import org.apache.ignite.internal.util.typedef.internal.U;

/**
 * Adapter for common interfaces in closures, reducers and predicates.
 */
public class GridPeerDeployAwareAdapter implements GridPeerDeployAware {
    /** */
    private static final long serialVersionUID = 0L;

    /** Peer deploy aware class. */
    protected transient GridPeerDeployAware pda;

    /**
     * Sets object that from which peer deployment information
     * will be copied, i.e. this lambda object will be peer deployed
     * using the same class loader as given object.
     * <p>
     * Note that in most cases Ignite attempts to automatically call this
     * method whenever lambda classes like closures and predicates are created that
     * wrap user object (the peer deploy information in such cases will be copied
     * from the user object).
     * <p>
     * In general, if user gets class not found exception during peer loading it is
     * very likely that peer deploy information was lost during wrapping of one object
     * into another.
     *
     * @param obj Peer deploy aware.
     */
    public void peerDeployLike(Object obj) {
        assert obj != null;

        pda = U.peerDeployAware(obj);
    }

    /** {@inheritDoc} */
    @Override public Class<?> deployClass() {
        if (pda == null)
            pda = U.detectPeerDeployAware(this);

        return pda.deployClass();
    }

    /** {@inheritDoc} */
    @Override public ClassLoader classLoader() {
        if (pda == null)
            pda = U.detectPeerDeployAware(this);

        return pda.classLoader();
    }
}