org.eclipse.smila.blackboard.path.Path.java Source code

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Here is the source code for org.eclipse.smila.blackboard.path.Path.java

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/***********************************************************************************************************************
 * Copyright (c) 2008 empolis GmbH and brox IT Solutions GmbH. All rights reserved. This program and the accompanying
 * materials are made available under the terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors: 
 * Dmitry Hazin (brox IT Solutions GmbH) - initial creator
 * Sebastian Voigt (Brox IT Solutions GmbH) - initial creator
 **********************************************************************************************************************/
package org.eclipse.smila.blackboard.path;

import java.io.Serializable;
import java.util.Iterator;
import java.util.Stack;

import org.apache.commons.lang.StringUtils;

/**
 * String format of attribute path is "attributeName1@index1/attributeName2@index2/...". the specification of index is
 * optional and defaults to 0. if the index refers to a literal or a sub-object depends on methods getting the argument
 */
public class Path implements Serializable, Iterable<PathStep> {

    /** The Constant SEPARATOR. */
    public static final char SEPARATOR = '/';

    /** The Constant serialVersionUID. */
    private static final long serialVersionUID = 4628822718743464377L;

    /** The path stack. */
    private Stack<PathStep> _pathStack = new Stack<PathStep>();

    /**
     * Instantiates a new path.
     */
    public Path() {

    }

    /**
     * Instantiates a new path by a given Path object.
     * 
     * @param path
     *          the path
     */
    public Path(Path path) {
        for (PathStep pathStep : path) {
            _pathStack.add(pathStep);
        }
    }

    /**
     * Instantiates a new path by parsing the attribute path string.
     * 
     * @param path
     *          the path
     */
    public Path(String path) {
        for (String pathStepString : StringUtils.split(path, SEPARATOR)) {
            final String[] pathStepParts = StringUtils.split(pathStepString, PathStep.LEFT_BRACKET);
            int index = 0;
            if ((pathStepParts.length > 1) && (pathStepParts[1].indexOf(PathStep.RIGHT_BRACKET) > 0)) {
                index = Integer.valueOf(pathStepParts[1].substring(0, pathStepParts[1].length() - 1));
            }
            _pathStack.add(new PathStep(pathStepParts[0], index));
        }
    }

    /**
     * Extends path with the given PathStep.
     * 
     * @param step
     *          the step
     * 
     * @return the path
     */
    public Path add(PathStep step) {
        _pathStack.add(step);
        return this;
    }

    /**
     * Creates PathStep and extends path with it.
     * 
     * @param attributeName
     *          the attribute name
     * 
     * @return the path
     */
    public Path add(String attributeName) {
        final PathStep pathStep = new PathStep(attributeName);
        return add(pathStep);
    }

    /**
     * Creates PathStep and extends path with it.
     * 
     * @param attributeName
     *          the attribute name
     * @param index
     *          the index
     * 
     * @return the path
     */
    public Path add(String attributeName, int index) {
        final PathStep pathStep = new PathStep(attributeName, index);
        return add(pathStep);
    }

    /**
     * Remove tail element of this. This modifies the object itself and returns it again for further modifications, e.g.
     * path.up().add("siblingAttribute");
     * 
     * @return the path
     */
    public Path up() {
        _pathStack.pop();
        return this;
    }

    /**
     * Increase index of tail step by 1.
     * 
     * @return the path
     */
    public Path incIndex() {
        _pathStack.peek().incIndex();
        return this;
    }

    /**
     * {@inheritDoc}
     */
    public Iterator<PathStep> iterator() {
        return _pathStack.iterator();
    }

    /**
     * Checks if the Path is empty.
     * 
     * @return true, if is empty
     */
    public boolean isEmpty() {
        return _pathStack.isEmpty();
    }

    /**
     * Gets the PathStep at the given index.
     * 
     * @param index
     *          the index
     * 
     * @return the string
     */
    public PathStep get(int index) {
        return _pathStack.get(index);
    }

    /**
     * Gets the PathStep name at the given index.
     * 
     * @param index
     *          the index
     * 
     * @return the string
     */
    public String getName(int index) {
        return _pathStack.get(index).getName();
    }

    /**
     * Gets the PathStep index at the given index.
     * 
     * @param index
     *          the index
     * 
     * @return the string
     */
    public int getIndex(int index) {
        return _pathStack.get(index).getIndex();
    }

    /**
     * Length of the Path.
     * 
     * @return the int
     */
    public int length() {
        return _pathStack.size();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public boolean equals(Object other) {
        if (other == this) {
            return true;
        }
        if (other instanceof Path) {
            final Path otherPath = (Path) other;
            final Iterator<PathStep> pathIterator1 = this.iterator();
            final Iterator<PathStep> pathIterator2 = otherPath.iterator();
            while (pathIterator1.hasNext() && pathIterator2.hasNext()) {
                final PathStep pathStep1 = pathIterator1.next();
                final PathStep pathStep2 = pathIterator2.next();
                if (!(pathStep1 == null ? pathStep2 == null : pathStep1.equals(pathStep2))) {
                    return false;
                }
            }
            return !(pathIterator1.hasNext() || pathIterator2.hasNext());
        }
        return false;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public int hashCode() {
        return _pathStack.hashCode();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String toString() {
        final StringBuilder str = new StringBuilder();
        for (PathStep pathStep : _pathStack) {
            str.append(pathStep.toString());
            str.append(SEPARATOR);
        }
        return str.toString();
    }

}