XMLProperties.java 20.8 KB
Newer Older
Matt Tucker's avatar
Matt Tucker committed
1 2 3 4 5
/**
 * $RCSfile$
 * $Revision$
 * $Date$
 *
6
 * Copyright (C) 2004 Jive Software. All rights reserved.
Matt Tucker's avatar
Matt Tucker committed
7
 *
8 9
 * This software is published under the terms of the GNU Public License (GPL),
 * a copy of which is included in this distribution.
Matt Tucker's avatar
Matt Tucker committed
10 11 12 13
 */

package org.jivesoftware.util;

14 15 16 17 18
import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;

Matt Tucker's avatar
Matt Tucker committed
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39
import java.io.*;
import java.util.*;

/**
 * Provides the the ability to use simple XML property files. Each property is
 * in the form X.Y.Z, which would map to an XML snippet of:
 * <pre>
 * &lt;X&gt;
 *     &lt;Y&gt;
 *         &lt;Z&gt;someValue&lt;/Z&gt;
 *     &lt;/Y&gt;
 * &lt;/X&gt;
 * </pre>
 * <p/>
 * The XML file is passed in to the constructor and must be readable and
 * writtable. Setting property values will automatically persist those value
 * to disk. The file encoding used is UTF-8.
 *
 * @author Derek DeMoro
 * @author Iain Shigeoka
 */
40
public class XMLProperties {
Matt Tucker's avatar
Matt Tucker committed
41 42

    private File file;
43
    private Document document;
Matt Tucker's avatar
Matt Tucker committed
44 45 46 47 48 49 50 51

    /**
     * Parsing the XML file every time we need a property is slow. Therefore,
     * we use a Map to cache property values that are accessed more than once.
     */
    private Map propertyCache = new HashMap();

    /**
Bill Lynch's avatar
Bill Lynch committed
52
     * Creates a new XMLPropertiesTest object.
Matt Tucker's avatar
Matt Tucker committed
53
     *
54 55 56
     * @param fileName the full path the file that properties should be read from
     *                 and written to.
     * @throws IOException if an error occurs loading the properties.
Matt Tucker's avatar
Matt Tucker committed
57
     */
58 59
    public XMLProperties(String fileName) throws IOException {
        this(new File(fileName));
Matt Tucker's avatar
Matt Tucker committed
60 61
    }

62 63 64 65 66 67 68 69 70 71 72
    /**
     * Loads XML properties from a stream.
     *
     * @param in the input stream of XML.
     * @throws IOException if an exception occurs when reading the stream.
     */
    public XMLProperties(InputStream in) throws IOException {
        Reader reader = new BufferedReader(new InputStreamReader(in));
        buildDoc(reader);
    }

Matt Tucker's avatar
Matt Tucker committed
73
    /**
Bill Lynch's avatar
Bill Lynch committed
74
     * Creates a new XMLPropertiesTest object.
Matt Tucker's avatar
Matt Tucker committed
75
     *
76 77
     * @param file the file that properties should be read from and written to.
     * @throws IOException if an error occurs loading the properties.
Matt Tucker's avatar
Matt Tucker committed
78
     */
79 80
    public XMLProperties(File file) throws IOException {
        this.file = file;
Matt Tucker's avatar
Matt Tucker committed
81 82 83 84 85 86 87 88
        if (!file.exists()) {
            // Attempt to recover from this error case by seeing if the
            // tmp file exists. It's possible that the rename of the
            // tmp file failed the last time Jive was running,
            // but that it exists now.
            File tempFile;
            tempFile = new File(file.getParentFile(), file.getName() + ".tmp");
            if (tempFile.exists()) {
89
                Log.error("WARNING: " + file.getName() + " was not found, but temp file from " +
Matt Tucker's avatar
Matt Tucker committed
90 91 92 93 94 95 96 97
                        "previous write operation was. Attempting automatic recovery." +
                        " Please check file for data consistency.");
                tempFile.renameTo(file);
            }
            // There isn't a possible way to recover from the file not
            // being there, so throw an error.
            else {
                throw new FileNotFoundException("XML properties file does not exist: "
98
                        + file.getName());
Matt Tucker's avatar
Matt Tucker committed
99 100 101 102
            }
        }
        // Check read and write privs.
        if (!file.canRead()) {
103
            throw new IOException("XML properties file must be readable: " + file.getName());
Matt Tucker's avatar
Matt Tucker committed
104 105
        }
        if (!file.canWrite()) {
106
            throw new IOException("XML properties file must be writable: " + file.getName());
Matt Tucker's avatar
Matt Tucker committed
107
        }
108 109 110

        FileReader reader = new FileReader(file);
        buildDoc(reader);
Matt Tucker's avatar
Matt Tucker committed
111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126
    }

    /**
     * Returns the value of the specified property.
     *
     * @param name the name of the property to get.
     * @return the value of the specified property.
     */
    public synchronized String getProperty(String name) {
        String value = (String)propertyCache.get(name);
        if (value != null) {
            return value;
        }

        String[] propName = parsePropertyName(name);
        // Search for this property by traversing down the XML heirarchy.
127
        Element element = document.getRootElement();
Matt Tucker's avatar
Matt Tucker committed
128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173
        for (int i = 0; i < propName.length; i++) {
            element = element.element(propName[i]);
            if (element == null) {
                // This node doesn't match this part of the property name which
                // indicates this property doesn't exist so return null.
                return null;
            }
        }
        // At this point, we found a matching property, so return its value.
        // Empty strings are returned as null.
        value = element.getTextTrim();
        if ("".equals(value)) {
            return null;
        }
        else {
            // Add to cache so that getting property next time is fast.
            propertyCache.put(name, value);
            return value;
        }
    }

    /**
     * Return all values who's path matches the given property
     * name as a String array, or an empty array if the if there
     * are no children. This allows you to retrieve several values
     * with the same property name. For example, consider the
     * XML file entry:
     * <pre>
     * &lt;foo&gt;
     *     &lt;bar&gt;
     *         &lt;prop&gt;some value&lt;/prop&gt;
     *         &lt;prop&gt;other value&lt;/prop&gt;
     *         &lt;prop&gt;last value&lt;/prop&gt;
     *     &lt;/bar&gt;
     * &lt;/foo&gt;
     * </pre>
     * If you call getProperties("foo.bar.prop") will return a string array containing
     * {"some value", "other value", "last value"}.
     *
     * @param name the name of the property to retrieve
     * @return all child property values for the given node name.
     */
    public String[] getProperties(String name) {
        String[] propName = parsePropertyName(name);
        // Search for this property by traversing down the XML heirarchy,
        // stopping one short.
174
        Element element = document.getRootElement();
Matt Tucker's avatar
Matt Tucker committed
175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222
        for (int i = 0; i < propName.length - 1; i++) {
            element = element.element(propName[i]);
            if (element == null) {
                // This node doesn't match this part of the property name which
                // indicates this property doesn't exist so return empty array.
                return new String[]{};
            }
        }
        // We found matching property, return names of children.
        Iterator iter = element.elementIterator(propName[propName.length - 1]);
        ArrayList props = new ArrayList();
        String value;
        while (iter.hasNext()) {
            // Empty strings are skipped.
            value = ((Element)iter.next()).getTextTrim();
            if (!"".equals(value)) {
                props.add(value);
            }
        }
        String[] childrenNames = new String[props.size()];
        return (String[])props.toArray(childrenNames);
    }

    /**
     * Return all values who's path matches the given property
     * name as a String array, or an empty array if the if there
     * are no children. This allows you to retrieve several values
     * with the same property name. For example, consider the
     * XML file entry:
     * <pre>
     * &lt;foo&gt;
     *     &lt;bar&gt;
     *         &lt;prop&gt;some value&lt;/prop&gt;
     *         &lt;prop&gt;other value&lt;/prop&gt;
     *         &lt;prop&gt;last value&lt;/prop&gt;
     *     &lt;/bar&gt;
     * &lt;/foo&gt;
     * </pre>
     * If you call getProperties("foo.bar.prop") will return a string array containing
     * {"some value", "other value", "last value"}.
     *
     * @param name the name of the property to retrieve
     * @return all child property values for the given node name.
     */
    public Iterator getChildProperties(String name) {
        String[] propName = parsePropertyName(name);
        // Search for this property by traversing down the XML heirarchy,
        // stopping one short.
223
        Element element = document.getRootElement();
Matt Tucker's avatar
Matt Tucker committed
224 225 226 227 228 229 230 231 232 233
        for (int i = 0; i < propName.length - 1; i++) {
            element = element.element(propName[i]);
            if (element == null) {
                // This node doesn't match this part of the property name which
                // indicates this property doesn't exist so return empty array.
                return Collections.EMPTY_LIST.iterator();
            }
        }
        // We found matching property, return names of children.
        Iterator iter = element.elementIterator(propName[propName.length - 1]);
234
        ArrayList<String> props = new ArrayList<String>();
Matt Tucker's avatar
Matt Tucker committed
235
        while (iter.hasNext()) {
236
            props.add(((Element)iter.next()).getName());
Matt Tucker's avatar
Matt Tucker committed
237 238 239 240
        }
        return props.iterator();
    }

241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272
    /**
     * Returns the value of the attribute of the given property name or <tt>null</tt>
     * if it doesn't exist. Note, this
     *
     * @param name the property name to lookup - ie, "foo.bar"
     * @param attribute the name of the attribute, ie "id"
     * @return the value of the attribute of the given property or <tt>null</tt> if
     *      it doesn't exist.
     */
    public String getAttribute(String name, String attribute) {
        if (name == null || attribute == null) {
            return null;
        }
        String[] propName = parsePropertyName(name);
        // Search for this property by traversing down the XML heirarchy.
        Element element = document.getRootElement();
        for (int i = 0; i < propName.length; i++) {
            String child = propName[i];
            element = element.element(child);
            if (element == null) {
                // This node doesn't match this part of the property name which
                // indicates this property doesn't exist so return empty array.
                break;
            }
        }
        if (element != null) {
            // Get its attribute values
            return element.attributeValue(attribute);
        }
        return null;
    }

Matt Tucker's avatar
Matt Tucker committed
273 274 275 276 277 278 279 280 281 282 283 284 285 286 287
    /**
     * Sets a property to an array of values. Multiple values matching the same property
     * is mapped to an XML file as multiple elements containing each value.
     * For example, using the name "foo.bar.prop", and the value string array containing
     * {"some value", "other value", "last value"} would produce the following XML:
     * <pre>
     * &lt;foo&gt;
     *     &lt;bar&gt;
     *         &lt;prop&gt;some value&lt;/prop&gt;
     *         &lt;prop&gt;other value&lt;/prop&gt;
     *         &lt;prop&gt;last value&lt;/prop&gt;
     *     &lt;/bar&gt;
     * &lt;/foo&gt;
     * </pre>
     *
288 289
     * @param name the name of the property.
     * @param values the values for the property (can be empty but not null).
Matt Tucker's avatar
Matt Tucker committed
290
     */
291
    public void setProperties(String name, List<String> values) {
Matt Tucker's avatar
Matt Tucker committed
292 293 294
        String[] propName = parsePropertyName(name);
        // Search for this property by traversing down the XML heirarchy,
        // stopping one short.
295
        Element element = document.getRootElement();
Matt Tucker's avatar
Matt Tucker committed
296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313
        for (int i = 0; i < propName.length - 1; i++) {
            // If we don't find this part of the property in the XML heirarchy
            // we add it as a new node
            if (element.element(propName[i]) == null) {
                element.addElement(propName[i]);
            }
            element = element.element(propName[i]);
        }
        String childName = propName[propName.length - 1];
        // We found matching property, clear all children.
        List toRemove = new ArrayList();
        Iterator iter = element.elementIterator(childName);
        while (iter.hasNext()) {
            toRemove.add(iter.next());
        }
        for (iter = toRemove.iterator(); iter.hasNext();) {
            element.remove((Element)iter.next());
        }
314 315 316
        // Add the new children.
        for (String value : values) {
            element.addElement(childName).setText(value);
Matt Tucker's avatar
Matt Tucker committed
317 318
        }
        saveProperties();
319 320 321 322 323 324

        // Generate event.
        Map params = new HashMap();
        params.put("value", values);
        PropertyEventDispatcher.dispatchEvent((String)name,
                PropertyEventDispatcher.EventType.xml_property_set, params);
Matt Tucker's avatar
Matt Tucker committed
325 326 327 328 329 330 331 332 333 334 335 336 337 338 339
    }

    /**
     * Return all children property names of a parent property as a String array,
     * or an empty array if the if there are no children. For example, given
     * the properties <tt>X.Y.A</tt>, <tt>X.Y.B</tt>, and <tt>X.Y.C</tt>, then
     * the child properties of <tt>X.Y</tt> are <tt>A</tt>, <tt>B</tt>, and
     * <tt>C</tt>.
     *
     * @param parent the name of the parent property.
     * @return all child property values for the given parent.
     */
    public String[] getChildrenProperties(String parent) {
        String[] propName = parsePropertyName(parent);
        // Search for this property by traversing down the XML heirarchy.
340
        Element element = document.getRootElement();
Matt Tucker's avatar
Matt Tucker committed
341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374
        for (int i = 0; i < propName.length; i++) {
            element = element.element(propName[i]);
            if (element == null) {
                // This node doesn't match this part of the property name which
                // indicates this property doesn't exist so return empty array.
                return new String[]{};
            }
        }
        // We found matching property, return names of children.
        List children = element.elements();
        int childCount = children.size();
        String[] childrenNames = new String[childCount];
        for (int i = 0; i < childCount; i++) {
            childrenNames[i] = ((Element)children.get(i)).getName();
        }
        return childrenNames;
    }

    /**
     * Sets the value of the specified property. If the property doesn't
     * currently exist, it will be automatically created.
     *
     * @param name  the name of the property to set.
     * @param value the new value for the property.
     */
    public synchronized void setProperty(String name, String value) {
        if (name == null) return;
        if (value == null) value = "";

        // Set cache correctly with prop name and value.
        propertyCache.put(name, value);

        String[] propName = parsePropertyName(name);
        // Search for this property by traversing down the XML heirarchy.
375
        Element element = document.getRootElement();
Matt Tucker's avatar
Matt Tucker committed
376 377 378 379 380 381 382 383 384 385
        for (int i = 0; i < propName.length; i++) {
            // If we don't find this part of the property in the XML heirarchy
            // we add it as a new node
            if (element.element(propName[i]) == null) {
                element.addElement(propName[i]);
            }
            element = element.element(propName[i]);
        }
        // Set the value of the property in this node.
        element.setText(value);
386
        // Write the XML properties to disk
Matt Tucker's avatar
Matt Tucker committed
387
        saveProperties();
388 389 390 391 392 393

        // Generate event.
        Map params = new HashMap();
        params.put("value", value);
        PropertyEventDispatcher.dispatchEvent((String)name,
                PropertyEventDispatcher.EventType.xml_property_set, params);
Matt Tucker's avatar
Matt Tucker committed
394 395 396 397 398 399 400 401 402 403 404 405 406
    }

    /**
     * Deletes the specified property.
     *
     * @param name the property to delete.
     */
    public synchronized void deleteProperty(String name) {
        // Remove property from cache.
        propertyCache.remove(name);

        String[] propName = parsePropertyName(name);
        // Search for this property by traversing down the XML heirarchy.
407
        Element element = document.getRootElement();
Matt Tucker's avatar
Matt Tucker committed
408 409 410 411 412 413 414 415 416 417 418
        for (int i = 0; i < propName.length - 1; i++) {
            element = element.element(propName[i]);
            // Can't find the property so return.
            if (element == null) {
                return;
            }
        }
        // Found the correct element to remove, so remove it...
        element.remove(element.element(propName[propName.length - 1]));
        // .. then write to disk.
        saveProperties();
419 420 421 422

        // Generate event.
        PropertyEventDispatcher.dispatchEvent((String)name,
                PropertyEventDispatcher.EventType.xml_property_deleted, Collections.emptyMap());
Matt Tucker's avatar
Matt Tucker committed
423 424
    }

425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443
    /**
     * Builds the document XML model up based the given reader of XML data.
     */
    private void buildDoc(Reader in) throws IOException {
        try {
            SAXReader xmlReader = new SAXReader();
            document = xmlReader.read(in);
        }
        catch (Exception e) {
            Log.error("Error reading XML properties", e);
            throw new IOException(e.getMessage());
        }
        finally {
            if (in != null) {
                in.close();
            }
        }
    }

Matt Tucker's avatar
Matt Tucker committed
444 445 446 447 448 449 450 451 452 453 454 455
    /**
     * Saves the properties to disk as an XML document. A temporary file is
     * used during the writing process for maximum safety.
     */
    private synchronized void saveProperties() {
        boolean error = false;
        // Write data out to a temporary file first.
        File tempFile = null;
        Writer writer = null;
        try {
            tempFile = new File(file.getParentFile(), file.getName() + ".tmp");
            writer = new FileWriter(tempFile);
456 457 458
            OutputFormat prettyPrinter = OutputFormat.createPrettyPrint();
            XMLWriter xmlWriter = new XMLWriter(writer, prettyPrinter);
            xmlWriter.write(document);
Matt Tucker's avatar
Matt Tucker committed
459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485
        }
        catch (Exception e) {
            Log.error(e);
            // There were errors so abort replacing the old property file.
            error = true;
        }
        finally {
            if (writer != null) {
                try {
                    writer.close();
                }
                catch (IOException e1) {
                    Log.error(e1);
                    error = true;
                }
            }
        }

        // No errors occured, so delete the main file.
        if (!error) {
            // Delete the old file so we can replace it.
            if (!file.delete()) {
                Log.error("Error deleting property file: " + file.getAbsolutePath());
                return;
            }
            // Copy new contents to the file.
            try {
486
                copy(tempFile, file);
Matt Tucker's avatar
Matt Tucker committed
487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524
            }
            catch (Exception e) {
                Log.error(e);
                // There were errors so abort replacing the old property file.
                error = true;
            }
            // If no errors, delete the temp file.
            if (!error) {
                tempFile.delete();
            }
        }
    }

    /**
     * Returns an array representation of the given Jive property. Jive
     * properties are always in the format "prop.name.is.this" which would be
     * represented as an array of four Strings.
     *
     * @param name the name of the Jive property.
     * @return an array representation of the given Jive property.
     */
    private String[] parsePropertyName(String name) {
        List propName = new ArrayList(5);
        // Use a StringTokenizer to tokenize the property name.
        StringTokenizer tokenizer = new StringTokenizer(name, ".");
        while (tokenizer.hasMoreTokens()) {
            propName.add(tokenizer.nextToken());
        }
        return (String[])propName.toArray(new String[propName.size()]);
    }

    public void setProperties(Map propertyMap) {
        Iterator iter = propertyMap.keySet().iterator();
        while (iter.hasNext()) {
            String propertyName = (String) iter.next();
            String propertyValue = (String) propertyMap.get(propertyName);
            setProperty(propertyName, propertyValue);
        }
525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576
    }

    /**
     * Copies the inFile to the outFile.
     *
     * @param inFile  The file to copy from
     * @param outFile The file to copy to
     * @throws IOException If there was a problem making the copy
     */
    private static void copy(File inFile, File outFile) throws IOException {
        FileInputStream fin = null;
        FileOutputStream fout = null;
        try {
            fin = new FileInputStream(inFile);
            fout = new FileOutputStream(outFile);
            copy(fin, fout);
        }
        finally {
            try {
                if (fin != null) fin.close();
            }
            catch (IOException e) {
                // do nothing
            }
            try {
                if (fout != null) fout.close();
            }
            catch (IOException e) {
                // do nothing
            }
        }
    }

    /**
     * Copies data from an input stream to an output stream
     *
     * @param in  The stream to copy data from
     * @param out The stream to copy data to
     * @throws IOException if there's trouble during the copy
     */
    private static void copy(InputStream in, OutputStream out) throws IOException {
        // do not allow other threads to whack on in or out during copy
        synchronized (in) {
            synchronized (out) {
                byte[] buffer = new byte[256];
                while (true) {
                    int bytesRead = in.read(buffer);
                    if (bytesRead == -1) break;
                    out.write(buffer, 0, bytesRead);
                }
            }
        }
Matt Tucker's avatar
Matt Tucker committed
577 578
    }
}