org.apache.oodt.cas.cli.util.CmdLineIterable.java Source code

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Here is the source code for org.apache.oodt.cas.cli.util.CmdLineIterable.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.oodt.cas.cli.util;

//JDK imports
import java.util.Iterator;
import java.util.List;

//Apache imports
import org.apache.commons.lang.Validate;

/**
 * An {@link Iterable} which allows multiple concurrent iterators which affect
 * each other, also allows you to increment iterators index manually. All
 * iterators handle termination safely. However, the catch being that you can
 * only iterate through this {@link Iterable} once, then you must create a new
 * object of it to iterate over it again.
 * 
 * @author bfoster (Brian Foster)
 */
public class CmdLineIterable<T> implements Iterable<T> {
    private int curIndex;
    private List<T> args;

    public CmdLineIterable(List<T> args) {
        Validate.notNull(args);

        curIndex = -1;
        this.args = args;
    }

    public List<T> getArgs() {
        return args;
    }

    public List<T> getArgsLeft() {
        return args.subList(curIndex, args.size());
    }

    public int getCurrentIndex() {
        return curIndex;
    }

    public void incrementIndex() {
        if (curIndex < args.size()) {
            curIndex++;
        }
    }

    public void descrementIndex() {
        if (curIndex > 0) {
            curIndex--;
        }
    }

    public T incrementAndGet() {
        incrementIndex();
        return getCurrentArg();
    }

    public T getAndIncrement() {
        T next = getCurrentArg();
        incrementIndex();
        return next;
    }

    public int numArgs() {
        return args.size();
    }

    public T getArg(int index) {
        return args.get(index);
    }

    public boolean hasNext() {
        return curIndex + 1 < args.size();
    }

    public T getCurrentArg() {
        if (curIndex == -1) {
            return incrementAndGet();
        } else if (curIndex > -1 && curIndex < args.size()) {
            return args.get(curIndex);
        } else {
            return null;
        }
    }

    public Iterator<T> iterator() {
        return new Iterator<T>() {

            public boolean hasNext() {
                return CmdLineIterable.this.hasNext();
            }

            public T next() {
                if (!hasNext()) {
                    throw new IndexOutOfBoundsException((curIndex + 1) + "");
                }
                return incrementAndGet();
            }

            public void remove() {
                // do nothing
            }

        };
    }
}