Commons JXPath example source code file (Step.java)

This example Commons JXPath source code file (Step.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons JXPath tags/keywords

expression, expression, nodetest, nodetest, nodetypetest, nodetypetest, step, step, string, stringbuffer, unknown

The Commons JXPath Step.java source code

/*
 * 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.commons.jxpath.ri.compiler;

import org.apache.commons.jxpath.ri.Compiler;

/**
 * @author Dmitri Plotnikov
 * @version $Revision: 652845 $ $Date: 2008-05-02 12:46:46 -0500 (Fri, 02 May 2008) $
 */
public class Step {
    private int axis;
    private NodeTest nodeTest;
    private Expression[] predicates;

    /**
     * Create a new Step.
     * @param axis axis code
     * @param nodeTest step test
     * @param predicates predicate expressions
     */
    protected Step(int axis, NodeTest nodeTest, Expression[] predicates) {
        this.axis = axis;
        this.nodeTest = nodeTest;
        this.predicates = predicates;
    }

    /**
     * Get the axis code.
     * @return int
     */
    public int getAxis() {
        return axis;
    }

    /**
     * Get the step test.
     * @return NodeTest
     */
    public NodeTest getNodeTest() {
        return nodeTest;
    }

    /**
     * Get the predicates.
     * @return Expression[]
     */
    public Expression[] getPredicates() {
        return predicates;
    }

    /**
     * Learn whether this step contains any predicate that is context dependent.
     * @return boolean
     */
    public boolean isContextDependent() {
        if (predicates != null) {
            for (int i = 0; i < predicates.length; i++) {
                if (predicates[i].isContextDependent()) {
                    return true;
                }
            }
        }
        return false;
    }

    public String toString() {
        StringBuffer buffer = new StringBuffer();
        int axis = getAxis();
        if (axis == Compiler.AXIS_CHILD) {
            buffer.append(nodeTest);
        }
        else if (axis == Compiler.AXIS_ATTRIBUTE) {
            buffer.append('@');
            buffer.append(nodeTest);
        }
        else if (axis == Compiler.AXIS_SELF
                && nodeTest instanceof NodeTypeTest
                && ((NodeTypeTest) nodeTest).getNodeType()
                    == Compiler.NODE_TYPE_NODE) {
            buffer.append(".");
        }
        else if (axis == Compiler.AXIS_PARENT
                && nodeTest instanceof NodeTypeTest
                && ((NodeTypeTest) nodeTest).getNodeType()
                    == Compiler.NODE_TYPE_NODE) {
            buffer.append("..");
        }
        else if (axis == Compiler.AXIS_DESCENDANT_OR_SELF
                && nodeTest instanceof NodeTypeTest
                && ((NodeTypeTest) nodeTest).getNodeType()
                    == Compiler.NODE_TYPE_NODE
                && (predicates == null || predicates.length == 0)) {
            buffer.append("");
        }
        else {
            buffer.append(axisToString(axis));
            buffer.append("::");
            buffer.append(nodeTest);
        }
        Expression[] predicates = getPredicates();
        if (predicates != null) {
            for (int i = 0; i < predicates.length; i++) {
                buffer.append('[');
                buffer.append(predicates[i]);
                buffer.append(']');
            }
        }
        return buffer.toString();
    }

    /**
     * Decode an axis code to its name.
     * @param axis int code
     * @return String name.
     * @see Compiler
     * @see http://www.w3.org/TR/xpath#axes
     */
    public static String axisToString(int axis) {
        switch (axis) {
            case Compiler.AXIS_SELF :
                return "self";
            case Compiler.AXIS_CHILD :
                return "child";
            case Compiler.AXIS_PARENT :
                return "parent";
            case Compiler.AXIS_ANCESTOR :
                return "ancestor";
            case Compiler.AXIS_ATTRIBUTE :
                return "attribute";
            case Compiler.AXIS_NAMESPACE :
                return "namespace";
            case Compiler.AXIS_PRECEDING :
                return "preceding";
            case Compiler.AXIS_FOLLOWING :
                return "following";
            case Compiler.AXIS_DESCENDANT :
                return "descendant";
            case Compiler.AXIS_ANCESTOR_OR_SELF :
                return "ancestor-or-self";
            case Compiler.AXIS_FOLLOWING_SIBLING :
                return "following-sibling";
            case Compiler.AXIS_PRECEDING_SIBLING :
                return "preceding-sibling";
            case Compiler.AXIS_DESCENDANT_OR_SELF :
                return "descendant-or-self";
            default:
                return "UNKNOWN";
        }
    }
}