java/alt2xml-out-xpath/src/cz/frantovo/alt2xml/out/xpath/XPathAction.java
author František Kučera <franta-hg@frantovo.cz>
Thu, 04 Sep 2014 00:39:11 +0200
changeset 63 89acb486bb52
parent 49 bec481687c1b
child 64 e2c691eedf4d
permissions -rw-r--r--
out-xpath: basics + AbstractDOMAction
     1 /**
     2  * Alt2XML
     3  * Copyright © 2014 František Kučera (frantovo.cz)
     4  *
     5  * This program is free software: you can redistribute it and/or modify
     6  * it under the terms of the GNU General Public License as published by
     7  * the Free Software Foundation, either version 3 of the License, or
     8  * (at your option) any later version.
     9  *
    10  * This program is distributed in the hope that it will be useful,
    11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    13  * GNU General Public License for more details.
    14  *
    15  * You should have received a copy of the GNU General Public License
    16  * along with this program. If not, see <http://www.gnu.org/licenses/>.
    17  */
    18 package cz.frantovo.alt2xml.out.xpath;
    19 
    20 import cz.frantovo.alt2xml.out.AbstractDOMAction;
    21 import cz.frantovo.alt2xml.out.ActionContext;
    22 import cz.frantovo.alt2xml.out.OutputActionException;
    23 import java.io.PrintWriter;
    24 import javax.xml.transform.dom.DOMResult;
    25 import javax.xml.xpath.XPath;
    26 import javax.xml.xpath.XPathExpression;
    27 import javax.xml.xpath.XPathExpressionException;
    28 import javax.xml.xpath.XPathFactory;
    29 import org.w3c.dom.Node;
    30 
    31 /**
    32  *
    33  * @author Ing. František Kučera (frantovo.cz)
    34  */
    35 public class XPathAction extends AbstractDOMAction {
    36 
    37 	public XPathAction(ActionContext actionContext) {
    38 		super(actionContext);
    39 	}
    40 
    41 	@Override
    42 	public void run(DOMResult domResult) throws OutputActionException {
    43 
    44 		// TODO: reuse
    45 		XPathFactory xpf = XPathFactory.newInstance();
    46 		XPath xp = xpf.newXPath();
    47 
    48 		// String expressionString = getActionContext().
    49 		String expressionString = "1+1";
    50 		expressionString = "//property[@name='ccc']";
    51 
    52 		try {
    53 			XPathExpression xpe = xp.compile(expressionString);
    54 
    55 			String result = xpe.evaluate(domResult.getNode());
    56 
    57 			try (PrintWriter out = new PrintWriter(getActionContext().getOutputStream())) {
    58 				out.println(result);
    59 			}
    60 
    61 		} catch (XPathExpressionException e) {
    62 			throw new OutputActionException("Unable to compile or evaluate XPath: " + expressionString, e);
    63 		}
    64 	}
    65 }