org.openmrs.module.UpdateFileParser.java Source code

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Here is the source code for org.openmrs.module.UpdateFileParser.java

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/**
 * This Source Code Form is subject to the terms of the Mozilla Public License,
 * v. 2.0. If a copy of the MPL was not distributed with this file, You can
 * obtain one at http://mozilla.org/MPL/2.0/. OpenMRS is also distributed under
 * the terms of the Healthcare Disclaimer located at http://openmrs.org/license.
 *
 * Copyright (C) OpenMRS Inc. OpenMRS is a registered trademark and the OpenMRS
 * graphic logo is a trademark of OpenMRS Inc.
 */
package org.openmrs.module;

import java.io.StringReader;
import java.util.List;
import java.util.Vector;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.openmrs.util.OpenmrsConstants;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;

/**
 * This class will parse an xml update.rdf file
 *
 * @version 1.0
 */
public class UpdateFileParser {

    private static Log log = LogFactory.getLog(UpdateFileParser.class);

    private String content;

    // these properties store the 'best fit' (most recent update that will fit with the current code version)
    private String moduleId = null;

    private String currentVersion = null;

    private String downloadURL = null;

    /**
     * Default constructor
     *
     * @param s String to parse (Contents of update.rdf file)
     */
    public UpdateFileParser(String s) {
        this.content = s;
    }

    /**
     * Parse the contents of the update.rdf file.
     *
     * @throws ModuleException
     */
    public void parse() throws ModuleException {
        StringReader stringReader = null;
        try {
            Document updateDoc = null;
            try {
                stringReader = new StringReader(content);
                InputSource inputSource = new InputSource(stringReader);
                inputSource.setSystemId("./");

                DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
                DocumentBuilder db = dbf.newDocumentBuilder();

                // Disable resolution of external entities. See TRUNK-3942 
                db.setEntityResolver(new EntityResolver() {

                    public InputSource resolveEntity(String publicId, String systemId) {
                        return new InputSource(new StringReader(""));
                    }
                });

                updateDoc = db.parse(inputSource);
            } catch (Exception e) {
                log.warn("Unable to parse content");
                throw new ModuleException("Error parsing update.rdf file: " + content, e);
            }

            Element rootNode = updateDoc.getDocumentElement();

            String configVersion = rootNode.getAttribute("configVersion");

            if (!validConfigVersions().contains(configVersion)) {
                throw new ModuleException(
                        "Invalid configVersion: '" + configVersion + "' found In content: " + content);
            }

            if ("1.0".equals(configVersion)) {
                // the only update in the xml file is the 'best fit'
                this.moduleId = getElement(rootNode, configVersion, "moduleId");
                this.currentVersion = getElement(rootNode, configVersion, "currentVersion");
                this.downloadURL = getElement(rootNode, configVersion, "downloadURL");
            } else if ("1.1".equals(configVersion)) {

                this.moduleId = rootNode.getAttribute("moduleId");

                NodeList nodes = rootNode.getElementsByTagName("update");
                this.currentVersion = ""; // default to the lowest version possible

                // loop over all 'update' tags
                for (Integer i = 0; i < nodes.getLength(); i++) {
                    Element currentNode = (Element) nodes.item(i);
                    String currentVersion = getElement(currentNode, configVersion, "currentVersion");
                    // if the currently saved version is less than the current tag
                    if (ModuleUtil.compareVersion(this.currentVersion, currentVersion) < 0) {
                        String requireOpenMRSVersion = getElement(currentNode, configVersion,
                                "requireOpenMRSVersion");
                        // if the openmrs code version is compatible, this node is a winner
                        if (requireOpenMRSVersion == null || ModuleUtil.matchRequiredVersions(
                                OpenmrsConstants.OPENMRS_VERSION_SHORT, requireOpenMRSVersion)) {
                            this.currentVersion = currentVersion;
                            this.downloadURL = getElement(currentNode, configVersion, "downloadURL");
                        }
                    }
                }
            }
        } catch (ModuleException e) {
            // rethrow the moduleException
            throw e;
        } finally {
            if (stringReader != null) {
                stringReader.close();
            }
        }

    }

    /**
     * Generic method to get a module tag
     *
     * @param element
     * @param version
     * @param tag
     * @return
     */
    private static String getElement(Element element, String version, String tag) {
        if (element.getElementsByTagName(tag).getLength() > 0) {
            return element.getElementsByTagName(tag).item(0).getTextContent();
        }
        return "";
    }

    /**
     * List of the valid sqldiff versions
     *
     * @return
     */
    private static List<String> validConfigVersions() {
        List<String> versions = new Vector<String>();
        versions.add("1.0");
        versions.add("1.1");
        return versions;
    }

    /**
     * @return the downloadURL
     */
    public String getDownloadURL() {
        return downloadURL;
    }

    /**
     * @return the moduleId
     */
    public String getModuleId() {
        return moduleId;
    }

    /**
     * @return the version
     */
    public String getCurrentVersion() {
        return currentVersion;
    }

}