Java XPath Get get(String path, Node e)

Description

get

License

Apache License

Declaration

public static String get(String path, Node e) 

Method Source Code

//package com.java2s;
/*//from   www.ja  v a 2  s. c o m
 * Copyright 2012 LIG SIGMA
 *
 * 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.
 */

import org.w3c.dom.Node;

import javax.xml.namespace.QName;

import javax.xml.xpath.*;

import java.util.HashMap;
import java.util.Map;

public class Main {
    private static XPath xpath;
    private static Map<String, XPathExpression> compiledString = new HashMap<String, XPathExpression>();

    public static String get(String path, Node e) {
        return (String) evaluateXPath(path, e, XPathConstants.STRING);
    }

    private static Object evaluateXPath(String path, Node e, QName type) {
        try {
            XPathExpression expr = compiledString.get(path);
            if (expr == null) {
                expr = xpath.compile(path);
                compiledString.put(path, expr);
            }
            return expr.evaluate(e, type);
        } catch (XPathExpressionException e1) {
            throw new IllegalStateException("Wrong XPATH expression: " + path, e1);
            //SHOULD NEVER HAPPEN IF THE EXPRESSIONS ARE WELL MADE INSIDE THE CODE
        }
    }
}

Related

1. getAttribute(String fileName, String xPathExpression, String attributeName)
2. getBaseLocation(byte[] metadata)
3. getBool(Node node, boolean def, XPathExpression expr)
4. getCache()