JMeter example source code file (XPathWrapper.java)

This example JMeter source code file (XPathWrapper.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 - JMeter tags/keywords

hashmap, io, map, map, non-nls-1, non-nls-1, opening, parser, sax, string, string, there's, threadlocal, transformerexception, util, xml, xpathfilecontainer, xpathfilecontainer, xpathwrapper

The JMeter XPathWrapper.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.jmeter.functions;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.TransformerException;

import org.apache.jorphan.logging.LoggingManager;
import org.apache.log.Logger;
import org.xml.sax.SAXException;

/**
 * This class wraps the XPathFileContainer for use across multiple threads.
 *
 * It maintains a list of nodelist containers, one for each file/xpath combination
 *
 */
public class XPathWrapper {

    private static final Logger log = LoggingManager.getLoggerForClass();

    /*
     * This Map serves two purposes:
     * - maps names to  containers
     * - ensures only one container per file across all threads
     * The key is the concatenation of the file name and the XPath string
     */
    //@GuardedBy("fileContainers")
    private static final Map<String, XPathFileContainer> fileContainers =
        new HashMap<String, XPathFileContainer>();

    /* The cache of file packs - for faster local access */
    private static final ThreadLocal<Map filePacks =
        new ThreadLocal<Map() {
        @Override
        protected Map<String, XPathFileContainer> initialValue() {
            return new HashMap<String, XPathFileContainer>();
        }
    };

    private XPathWrapper() {// Prevent separate instantiation
        super();
    }

    private static XPathFileContainer open(String file, String xpathString) {
        String tname = Thread.currentThread().getName();
        log.info(tname+": Opening " + file);
        XPathFileContainer frcc=null;
        try {
            frcc = new XPathFileContainer(file, xpathString);
        } catch (FileNotFoundException e) {
            log.warn(e.getLocalizedMessage());
        } catch (IOException e) {
            log.warn(e.getLocalizedMessage());
        } catch (ParserConfigurationException e) {
            log.warn(e.getLocalizedMessage());
        } catch (SAXException e) {
            log.warn(e.getLocalizedMessage());
        } catch (TransformerException e) {
            log.warn(e.getLocalizedMessage());
        }
        return frcc;
    }

    /**
     * Not thread-safe - must be called from a synchronized method.
     *
     * @param file
     * @param xpathString
     * @return the next row from the file container
     */
    public static String getXPathString(String file, String xpathString) {
        Map<String, XPathFileContainer> my = filePacks.get();
        String key = file+xpathString;
        XPathFileContainer xpfc = my.get(key);
        if (xpfc == null) // We don't have a local copy
        {
            synchronized(fileContainers){
                xpfc = fileContainers.get(key);
                if (xpfc == null) { // There's no global copy either
                    xpfc=open(file, xpathString);
                }
                if (xpfc != null) {
                    fileContainers.put(key, xpfc);// save the global copy
                }
            }
            // TODO improve the error handling
            if (xpfc == null) {
                log.error("XPathFileContainer is null!");
                return ""; //$NON-NLS-1$
            }
            my.put(key,xpfc); // save our local copy
        }
        if (xpfc.size()==0){
            log.warn("XPathFileContainer has no nodes: "+file+" "+xpathString);
            return ""; //$NON-NLS-1$
        }
        int currentRow = xpfc.nextRow();
        log.debug("getting match number " + currentRow);
        return xpfc.getXPathString(currentRow);
    }

    public static void clearAll() {
        log.debug("clearAll()");
        filePacks.get().clear();
        String tname = Thread.currentThread().getName();
        log.info(tname+": clearing container");
        synchronized (fileContainers) {
            fileContainers.clear();
        }
    }
}