org.apache.olingo.ext.proxy.commons.EntitySetIterator.java Source code

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Here is the source code for org.apache.olingo.ext.proxy.commons.EntitySetIterator.java

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/*
 * 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.olingo.ext.proxy.commons;

import java.io.Serializable;
import java.net.URI;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.NoSuchElementException;

import org.apache.commons.lang3.tuple.Triple;
import org.apache.olingo.client.api.domain.ClientAnnotation;
import org.apache.olingo.ext.proxy.api.EntityCollection;
import org.apache.olingo.ext.proxy.api.EntityType;

class EntitySetIterator<T extends EntityType<?>, KEY extends Serializable, EC extends EntityCollection<T, ?, ?>>
        implements Iterator<T> {

    private final EntitySetInvocationHandler<T, KEY, EC> esi;

    private URI next;

    private Iterator<T> current;

    EntitySetIterator(final URI uri, EntitySetInvocationHandler<T, KEY, EC> esi) {
        this.esi = esi;
        this.next = uri;
        this.current = Collections.<T>emptyList().iterator();
    }

    @Override
    public boolean hasNext() {
        final boolean res;
        if (this.current.hasNext()) {
            res = true;
        } else if (this.next == null) {
            res = false;
        } else {
            goOn();
            res = current.hasNext();
        }
        return res;
    }

    @Override
    public T next() {
        T res;
        try {
            res = this.current.next();
        } catch (NoSuchElementException e) {
            if (this.next == null) {
                throw e;
            }
            goOn();
            res = next();
        }

        return res;
    }

    @Override
    public void remove() {
        this.current.remove();
    }

    private void goOn() {
        final Triple<List<T>, URI, List<ClientAnnotation>> entitySet = esi.fetchPartial(this.next,
                this.esi.getTypeRef());
        this.current = entitySet.getLeft().iterator();
        this.next = entitySet.getMiddle();
    }
}