com.hubspot.jinjava.util.ObjectIterator.java Source code

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Here is the source code for com.hubspot.jinjava.util.ObjectIterator.java

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/**********************************************************************
 * Copyright (c) 2014 HubSpot Inc.
 *
 * 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.hubspot.jinjava.util;

import java.util.Collection;
import java.util.Iterator;
import java.util.Map;

import com.google.common.collect.Iterators;

public final class ObjectIterator {

    private ObjectIterator() {
    }

    @SuppressWarnings("unchecked")
    public static ForLoop getLoop(Object obj) {
        if (obj == null) {
            return new ForLoop(Iterators.emptyIterator(), 0);
        }
        // collection
        if (obj instanceof Collection) {
            Collection<Object> clt = (Collection<Object>) obj;
            return new ForLoop(clt.iterator(), clt.size());
        }
        // array
        if (obj.getClass().isArray()) {
            Object[] arr = (Object[]) obj;
            return new ForLoop(Iterators.forArray(arr), arr.length);
        }
        // map
        if (obj instanceof Map) {
            Collection<Object> clt = ((Map<Object, Object>) obj).values();
            return new ForLoop(clt.iterator(), clt.size());
        }
        // iterable,iterator
        if (obj instanceof Iterable) {
            return new ForLoop(((Iterable<Object>) obj).iterator());
        }
        if (obj instanceof Iterator) {
            return new ForLoop((Iterator<Object>) obj);
        }
        // others
        return new ForLoop(Iterators.singletonIterator(obj), 1);
    }

}