Java > Open Source Codes > org > archive > crawler > settings > ComplexType


1 /* ComplexType
2  *
3  * $Id: ComplexType.java,v 1.22.2.1 2007/01/13 01:31:26 stack-sf Exp $
4  *
5  * Created on Dec 17, 2003
6  *
7  * Copyright (C) 2004 Internet Archive.
8  *
9  * This file is part of the Heritrix web crawler (crawler.archive.org).
10  *
11  * Heritrix is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU Lesser Public License as published by
13  * the Free Software Foundation; either version 2.1 of the License, or
14  * any later version.
15  *
16  * Heritrix is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19  * GNU Lesser Public License for more details.
20  *
21  * You should have received a copy of the GNU Lesser Public License
22  * along with Heritrix; if not, write to the Free Software
23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
24  */
25 package org.archive.crawler.settings;
26
27 import java.util.ArrayList ;
28 import java.util.HashMap ;
29 import java.util.Iterator ;
30 import java.util.List ;
31 import java.util.Map ;
32 import java.util.Stack ;
33 import java.util.logging.Level ;
34 import java.util.logging.Logger ;
35
36 import javax.management.Attribute ;
37 import javax.management.AttributeList ;
38 import javax.management.AttributeNotFoundException ;
39 import javax.management.DynamicMBean ;
40 import javax.management.InvalidAttributeValueException ;
41 import javax.management.MBeanAttributeInfo ;
42 import javax.management.MBeanException ;
43 import javax.management.MBeanInfo ;
44 import javax.management.ReflectionException ;
45
46 import org.apache.commons.httpclient.URIException;
47 import org.archive.crawler.datamodel.CandidateURI;
48 import org.archive.crawler.datamodel.CrawlOrder;
49 import org.archive.crawler.datamodel.CrawlURI;
50 import org.archive.crawler.settings.Constraint.FailedCheck;
51 import org.archive.net.UURI;
52
53 /** Superclass of all configurable modules.
54  *
55  * This class is in many ways the heart of the settings framework. All modules
56  * that should be configurable extends this class or one of its subclasses.
57  *
58  * All subclasses of this class will automatically conform to the
59  * JMX DynamicMBean. You could then use the {@link #getMBeanInfo()} method to
60  * investigate which attributes this module supports and then use the
61  * {@link #getAttribute(String)} and {@link #setAttribute(Attribute)} methods to
62  * alter the attributes values.
63  *
64  * Because the settings framework supports per domain/host settings there is
65  * also available context sensitive versions of the DynamicMBean methods.
66  * If you use the non context sensitive methods, it is the global settings
67  * that will be altered.
68  *
69  * @author John Erik Halse
70  */
71 public abstract class ComplexType extends Type implements DynamicMBean {
72     private static Logger logger =
73         Logger.getLogger("org.archive.crawler.settings.ComplexType");
74
75     private transient SettingsHandler settingsHandler;
76     private transient ComplexType parent;
77     private String description;
78     private String absoluteName;
79     private final List <Type> definition = new ArrayList <Type>();
80     protected final Map <String ,Type> definitionMap = new HashMap <String ,Type>();
81     private boolean initialized = false;
82     private String [] preservedFields = new String [0];
83
84     /**
85      * Private constructor to make sure that no one
86      * instantiates this class with the empty constructor.
87      */
88     private ComplexType() {
89         super(null, null);
90     }
91
92     /** Creates a new instance of ComplexType.
93      *
94      * @param name the name of the element.
95      * @param description the description of the element.
96      */
97     public ComplexType(String name, String description) {
98         super(name, null);
99         this.description = description.intern();
100     }
101
102     protected void setAsOrder(SettingsHandler settingsHandler)
103     throws InvalidAttributeValueException {
104         this.settingsHandler = settingsHandler;
105         this.absoluteName = "";
106         globalSettings().addTopLevelModule((CrawlOrder) this);
107         addComplexType(settingsHandler.getSettingsObject(null), this);
108         this.parent = null;
109     }
110
111     /** Get the global settings object (aka order).
112      *
113      * @return the global settings object.
114      */
115     public CrawlerSettings globalSettings() {
116         if (settingsHandler == null) {
117             return null;
118         }
119         return settingsHandler.getSettingsObject(null);
120     }
121
122     public Type addElement(CrawlerSettings settings, Type type)
123         throws InvalidAttributeValueException {
124         getOrCreateDataContainer(settings).addElementType(type);
125         if (type instanceof ComplexType) {
126             addComplexType(settings, (ComplexType) type);
127         }
128         return type;
129     }
130
131     private ComplexType addComplexType(CrawlerSettings settings,
132             ComplexType object) throws InvalidAttributeValueException {
133
134         if (this.settingsHandler == null) {
135             throw new IllegalStateException ("Can't add ComplexType to 'free' ComplexType");
136         }
137         setupVariables(object);
138         settings.addComplexType(object);
139         if (!object.initialized) {
140             Iterator it = object.definition.iterator();
141             while (it.hasNext()) {
142                 Type t = (Type) it.next();
143                 object.addElement(settings, t);
144             }
145             object.earlyInitialize(settings);
146         }
147         object.initialized = true;
148
149         return object;
150     }
151
152     private ComplexType replaceComplexType(CrawlerSettings settings,
153             ComplexType object) throws InvalidAttributeValueException ,
154             AttributeNotFoundException {
155         if (this.settingsHandler == null) {
156             throw new IllegalStateException (
157                     "Can't add ComplexType to 'free' ComplexType");
158         }
159         String [] preservedFields = object.getPreservedFields();
160
161         setupVariables(object);
162
163         DataContainer oldData = settings.getData(object);
164         settings.addComplexType(object);
165         DataContainer newData = settings.getData(object);
166
167         if (!object.initialized) {
168             Iterator it = object.definition.iterator();
169             while (it.hasNext()) {
170                 Type t = (Type) it.next();
171
172                 // Check if attribute should be copied from old object.
173 boolean found = false;
174                 if (preservedFields.length > 0) {
175                     for (int i = 0; i < preservedFields.length; i++) {
176                         if (preservedFields[i].equals(t.getName())) {
177                             found = true;
178                             break;
179                         }
180                     }
181                 }
182                 if (found && oldData.copyAttribute(t.getName(), newData)) {
183                     if (t instanceof ComplexType) {
184                         object.setupVariables((ComplexType) t);
185                     }
186                 } else {
187                     object.addElement(settings, t);
188                 }
189             }
190             object.earlyInitialize(settings);
191         }
192         object.initialized = true;
193
194         return object;
195     }
196
197     /** Set a list of attribute names that the complex type should attempt to
198      * preserve if the module is exchanged with an other one.
199      *
200      * @param preservedFields array of attributenames to preserve.
201      */
202     protected void setPreservedFields(String [] preservedFields) {
203         this.preservedFields = preservedFields;
204     }
205
206     /** Get a list of attribute names that the complex type should attempt to
207      * preserve if the module is exchanged with an other one.
208      *
209      * @return an array of attributenames to preserve.
210      */
211     protected String [] getPreservedFields() {
212         return this.preservedFields;
213     }
214
215     /** Get the active data container for this ComplexType for a specific
216      * settings object.
217      *
218      * If no value has been overridden on the settings object for this
219      * ComplexType, then it traverses up until it find a DataContainer with
220      * values for this ComplexType.
221      *
222      * This method should probably not be called from user code. It is a helper
223      * method for the settings framework.
224      *
225      * @param context Context from which we get settings.
226      * @return the active DataContainer.
227      */
228     protected DataContainer getDataContainerRecursive(Context context) {
229         if (context.settings == null) {
230             return null;
231         }
232         DataContainer data = context.settings.getData(this);
233         if (data == null && context.settings.getParent(context.uri) != null) {
234             context.settings = context.settings.getParent(context.uri);
235             data = getDataContainerRecursive(context);
236         }
237         return data;
238     }
239
240     /** Get the active data container for this ComplexType for a specific
241      * settings object.
242      *
243      * If the key has not been overridden on the settings object for this
244      * ComplexType, then it traverses up until it find a DataContainer with
245      * the key for this ComplexType.
246      *
247      * This method should probably not be called from user code. It is a helper
248      * method for the settings framework.
249      *
250      * @param context the settings object for which the {@link DataContainer}
251      * is active.
252      * @param key the key to look for.
253      * @return the active DataContainer.
254      * @throws AttributeNotFoundException
255      */
256     protected DataContainer getDataContainerRecursive(Context context,
257             String key) throws AttributeNotFoundException {
258         Context c = new Context(context.settings, context.uri);
259         DataContainer data = getDataContainerRecursive(c);
260         while (data != null) {
261             if (data.containsKey(key)) {
262                 return data;
263             }
264             c.settings = data.getSettings().getParent(c.uri);
265             data = getDataContainerRecursive(c);
266         }
267         throw new AttributeNotFoundException (key);
268     }
269
270     /** Sets up some variables for a new complex type.
271      *
272      * The complex type is set up to be an attribute of
273      * this complex type.
274      *
275      * @param object to be set up.
276      */
277     private void setupVariables(ComplexType object) {
278         object.parent = this;
279         object.settingsHandler = getSettingsHandler();
280         object.absoluteName =
281             (getAbsoluteName() + '/' + object.getName()).intern();
282     }
283
284     public SettingsHandler getSettingsHandler() {
285         return settingsHandler;
286     }
287
288     /** Get the absolute name of this ComplexType.
289      *
290      * The absolute name is like a file path with the name of the element
291      * prepended by all the parents names separated by slashes.
292      * @return Absolute name.
293      */
294     public String getAbsoluteName() {
295         return absoluteName;
296     }
297
298     /**
299      * Get settings object valid for a URI.
300      * <p/>
301      * This method takes an object,
302      * try to convert it into a {@link CrawlURI} and then tries to get the
303      * settings object from it. If this fails, then the global settings object
304      * is returned.
305      * <p/>
306      * If the requested attribute is not set on this settings
307      * object it tries its parent until it gets a settings object where this
308      * attribute is set is found. If nothing is found, global settings is
309      * returned.
310      *
311      * @param o possible {@link CrawlURI}.
312      * @param attributeName the attribute that should have a value set on the
313      * returned settings object.
314      * @return the settings object valid for the URI.
315      */
316     Context getSettingsFromObject(Object o, String attributeName) {
317         Context context;
318         if (o == null) {
319             context = null;
320         } else if (o instanceof Context) {
321             context = (Context) o;
322         } else if (o instanceof CrawlerSettings) {
323             context = new Context((CrawlerSettings) o, null);
324         } else if (o instanceof UURI || o instanceof CandidateURI) {
325             // Try to get settings for URI that has no references to a
326 // CrawlServer [SIC - CrawlURI may have CrawlServer -gjm]
327 context = new Context();
328             context.uri = (o instanceof CandidateURI)?
329                 ((CandidateURI) o).getUURI(): (UURI)o;
330             try {
331                context.settings = getSettingsHandler().
332                    getSettings(context.uri.getReferencedHost(),
333                        context.uri);
334             }
335             catch (URIException e1) {
336                 logger.severe("Failed to get host");
337             }
338
339             if (attributeName != null) {
340                 try {
341                     context.settings =
342                         getDataContainerRecursive(context, attributeName).
343                             getSettings();
344                 } catch (AttributeNotFoundException e) {
345                     // Nothing found, globals will be used
346 }
347             }
348         } else {
349             logger.warning("Unknown object type: " +
350                 o.getClass().getName());
351             context = null;
352         }
353
354         // if settings could not be resolved use globals.
355 if (context == null) {
356             context = new Context(globalSettings(), null);
357         }
358         return context;
359     }
360
361     /** Get settings object valid for a URI.
362     *
363     * This method takes an object, try to convert it into a {@link CrawlURI}
364     * and then tries to get the settings object from it. If this fails, then
365     * the global settings object is returned.
366     *
367     * @param o possible {@link CrawlURI}.
368     * @return the settings object valid for the URI.
369     */
370     Context getSettingsFromObject(Object o) {
371         return getSettingsFromObject(o, null);
372     }
373
374     /** Returns true if an element is overridden for this settings object.
375      *
376      * @param settings the settings object to investigate.
377      * @param name the name of the element to check.
378      * @return true if element is overridden for this settings object, false
379      * if not set here or is first defined here.
380      * @throws AttributeNotFoundException if element doesn't exist.
381      */
382     public boolean isOverridden(CrawlerSettings settings, String name)
383             throws AttributeNotFoundException {
384         settings = settings == null ? globalSettings() : settings;
385         DataContainer data = settings.getData(this);
386         if (data == null || !data.containsKey(name)) {
387             return false;
388         }
389
390         // Try to find attribute, will throw an exception if not found.
391 Context context = new Context(settings.getParent(), null);
392         getDataContainerRecursive(context, name);
393         return true;
394     }
395
396     /** Obtain the value of a specific attribute from the crawl order.
397      *
398      * If the attribute doesn't exist in the crawl order, the default
399      * value will be returned.
400      *
401      * @param name the name of the attribute to be retrieved.
402      * @return The value of the attribute retrieved.
403      * @throws AttributeNotFoundException
404      * @throws MBeanException
405      * @throws ReflectionException
406      */
407     public Object getAttribute(String name)
408         throws AttributeNotFoundException , MBeanException , ReflectionException {
409         return getAttribute(null, name);
410     }
411
412     /** Obtain the value of a specific attribute that is valid for a
413      * specific CrawlURI.
414      *
415      * This method will try to get the attribute from the host settings
416      * valid for the CrawlURI. If it is not found it will traverse the
417      * settings up to the order and as a last resort deliver the default
418      * value. This is also the case if the CrawlURI is null or if the CrawlURI
419      * hasn't been assigned a CrawlServer.
420      *
421      * @param name the name of the attribute to be retrieved.
422      * @param uri the CrawlURI that this attribute should be valid for.
423      * @return The value of the attribute retrieved.
424      * @see #getAttribute(Object settings, String name)
425      * @throws AttributeNotFoundException
426      */
427     public Object getAttribute(String name, CrawlURI uri)
428         throws AttributeNotFoundException {
429         return getAttribute(uri, name);
430     }
431     
432     /**
433      * Obtain the value of a specific attribute that is valid for a specific
434      * CrawlerSettings object.<p>
435      *
436      * This method will first try to get a settings object from the supplied
437      * context, then try to look up the attribute from this settings object. If
438      * it is not found it will traverse the settings up to the order and as a
439      * last resort deliver the default value.
440      *
441      * @param context the object to get the settings from.
442      * @param name the name of the attribute to be retrieved.
443      * @return The value of the attribute retrieved.
444      * @see CrawlerSettings
445      * @throws AttributeNotFoundException
446      */
447     public Object getAttribute(Object context, String name)
448         throws AttributeNotFoundException {
449         Context ctxt = getSettingsFromObject(context);
450
451         // If settings is not set, return the default value
452 if (ctxt.settings == null) {
453             try {
454                 return ((Type) definitionMap.get(name)).getDefaultValue();
455             } catch (NullPointerException e) {
456                 throw new AttributeNotFoundException (
457                         "Could not find attribute: " + name);
458             }
459         }
460
461         return getDataContainerRecursive(ctxt, name).get(name);
462     }
463
464     /**
465      * Obtain the value of a specific attribute that is valid for a specific
466      * CrawlerSettings object.
467      * <p>
468      *
469      * This method will first try to get a settings object from the supplied
470      * context, then try to look up the attribute from this settings object. If
471      * it is not found it will traverse the settings up to the order and as a
472      * last resort deliver the default value.
473      * <p>
474      *
475      * The only difference from the {@link #getAttribute(Object, String)}is
476      * that this method doesn't throw any checked exceptions. If an undefined
477      * attribute is requested from a ComplexType, it is concidered a bug and a
478      * runtime exception is thrown instead.
479      *
480      * @param context the object to get the settings from.
481      * @param name the name of the attribute to be retrieved.
482      * @return The value of the attribute retrieved.
483      * @see #getAttribute(Object, String)
484      * @see CrawlerSettings
485      * @throws IllegalArgumentException
486      */
487     public Object getUncheckedAttribute(Object context, String name) {
488         try {
489             return getAttribute(context, name);
490         } catch (AttributeNotFoundException e) {
491             throw new IllegalArgumentException ("Was passed '" + name +
492                 "' and got this exception: " + e);
493         }
494     }
495
496     /** Obtain the value of a specific attribute that is valid for a
497      * specific CrawlerSettings object.
498      *
499      * This method will try to get the attribute from the supplied host
500      * settings object. If it is not found it will return <code>null</code>
501      * and not try to investigate the hierarchy of settings.
502      *
503      * @param settings the CrawlerSettings object to search for this attribute.
504      * @param name the name of the attribute to be retrieved.
505      * @return The value of the attribute retrieved or null if its not set.
506      * @see CrawlerSettings
507      * @throws AttributeNotFoundException is thrown if the attribute doesn't
508      * exist.
509      */
510     public Object getLocalAttribute(CrawlerSettings settings, String name)
511             throws AttributeNotFoundException {
512
513         settings = settings == null ? globalSettings() : settings;
514
515         DataContainer data = settings.getData(this);
516         if (data != null && data.containsKey(name)) {
517             // Attribute was found return it.
518 return data.get(name);
519         }
520         // Try to find the attribute, will throw an exception if not found.
521 Context context = new Context(settings, null);
522         getDataContainerRecursive(context, name);
523         return null;
524     }
525
526     /** Set the value of a specific attribute of the ComplexType.
527      *
528      * This method sets the specific attribute for the order file.
529      *
530      * @param attribute The identification of the attribute to be set and the
531      * value it is to be set to.
532      * @throws AttributeNotFoundException is thrown if there is no attribute
533      * with this name.
534      * @throws InvalidAttributeValueException is thrown if the attribute is of
535      * wrong type and cannot be converted to the right type.
536      * @throws MBeanException this is to conform to the MBean specification, but
537      * this exception is never thrown, though this might change in the
538      * future.
539      * @throws ReflectionException this is to conform to the MBean specification, but
540      * this exception is never thrown, though this might change in the
541      * future.
542      * @see javax.management.DynamicMBean#setAttribute(javax.management.Attribute)
543      */
544     public synchronized final void setAttribute(Attribute attribute)
545         throws
546             AttributeNotFoundException ,
547             InvalidAttributeValueException ,
548             MBeanException ,
549             ReflectionException {
550         setAttribute(settingsHandler.getSettingsObject(null), attribute);
551     }
552
553     /** Set the value of a specific attribute of the ComplexType.
554      *
555      * This method is an extension to the Dynamic MBean specification so that
556      * it is possible to set the value for a CrawlerSettings object other than
557      * the settings object representing the order.
558      *
559      * @param settings the settings object for which this attributes value is valid
560      * @param attribute The identification of the attribute to be set and the
561      * value it is to be set to.
562      * @throws AttributeNotFoundException is thrown if there is no attribute
563      * with this name.
564      * @throws InvalidAttributeValueException is thrown if the attribute is of
565      * wrong type and cannot be converted to the right type.
566      * @see javax.management.DynamicMBean#setAttribute(javax.management.Attribute)
567      */
568     public synchronized final void setAttribute(CrawlerSettings settings,
569             Attribute attribute) throws InvalidAttributeValueException ,
570             AttributeNotFoundException {
571
572         if(settings==null){
573             settings = globalSettings();
574         }
575
576         DataContainer data = getOrCreateDataContainer(settings);
577         Object value = attribute.getValue();
578
579         ModuleAttributeInfo attrInfo = (ModuleAttributeInfo) getAttributeInfo(
580                 settings.getParent(), attribute.getName());
581
582         ModuleAttributeInfo localAttrInfo = (ModuleAttributeInfo) data
583                 .getAttributeInfo(attribute.getName());
584
585         // Check if attribute exists
586 if (attrInfo == null && localAttrInfo == null) {
587             throw new AttributeNotFoundException (attribute.getName());
588         }
589
590         // Check if we are overriding and if that is allowed for this attribute
591 if (localAttrInfo == null) {
592             if (!attrInfo.isOverrideable()) {
593                 throw new InvalidAttributeValueException (
594                         "Attribute not overrideable: " + attribute.getName());
595             }
596             localAttrInfo = new ModuleAttributeInfo(attrInfo);
597         }
598
599         // Check if value is of correct type. If not, see if it is
600 // a string and try to turn it into right type
601 Class typeClass = getDefinition(attribute.getName()).getLegalValueType();
602         if (!(typeClass.isInstance(value)) && value instanceof String ) {
603             try {
604                 value = SettingsHandler.StringToType((String ) value,
605                         SettingsHandler.getTypeName(typeClass.getName()));
606             } catch (ClassCastException e) {
607                 throw new InvalidAttributeValueException (
608                         "Unable to decode string '" + value + "' into type '"
609                                 + typeClass.getName() + "'");
610             }
611         }
612
613         // Check if the attribute value is legal
614 FailedCheck error = checkValue(settings, attribute.getName(), value);
615         if (error != null) {
616             if (error.getLevel() == Level.SEVERE) {
617                 throw new InvalidAttributeValueException (error.getMessage());
618             } else if (error.getLevel() == Level.WARNING) {
619                 if (!getSettingsHandler().fireValueErrorHandlers(error)) {
620                     throw new InvalidAttributeValueException (error.getMessage());
621                 }
622             } else {
623                 getSettingsHandler().fireValueErrorHandlers(error);
624             }
625         }
626
627         // Everything ok, set it
628 localAttrInfo.setType(value);
629         Object oldValue = data.put(attribute.getName(), localAttrInfo, value);
630
631         // If the attribute is a complex type other than the old value,
632 // make sure that all sub attributes are correctly set
633 if (value instanceof ComplexType && value != oldValue) {
634             ComplexType complex = (ComplexType) value;
635             replaceComplexType(settings, complex);
636         }
637     }
638
639     /**
640      * Get the content type definition for an attribute.
641      *
642      * @param attributeName the name of the attribute to get definition for.
643      * @return the content type definition for the attribute.
644      */
645     Type getDefinition(String attributeName) {
646         return (Type) definitionMap.get(attributeName);
647     }
648
649     /**
650      * Check an attribute to see if it fulfills all the constraints set on the
651      * definition of this attribute.
652      *
653      * @param settings the CrawlerSettings object for which this check was
654      * executed.
655      * @param attributeName the name of the attribute to check.
656      * @param value the value to check.
657      * @return null if everything is ok, otherwise it returns a FailedCheck
658      * object with detailed information of what went wrong.
659      */
660     public FailedCheck checkValue(CrawlerSettings settings,
661             String attributeName, Object value) {
662         return checkValue(settings, attributeName,
663                 getDefinition(attributeName), value);
664     }
665
666     FailedCheck checkValue(CrawlerSettings settings, String attributeName,
667             Type definition, Object value) {
668         FailedCheck res = null;
669
670         // Check if value fulfills any constraints
671 List constraints = definition.getConstraints();
672         if (constraints != null) {
673             for (Iterator it = constraints.iterator(); it.hasNext()
674                     && res == null;) {
675                 res = ((Constraint) it.next()).check(settings, this,
676                         definition, value);
677             }
678         }
679
680         return res;
681     }
682
683     /** Unset an attribute on a per host level.
684      *
685      * This methods removes an override on a per host or per domain level.
686      *
687      * @param settings the settings object for which the attribute should be
688      * unset.
689      * @param name the name of the attribute.
690      * @return The removed attribute or null if nothing was removed.
691      * @throws AttributeNotFoundException is thrown if the attribute name
692      * doesn't exist.
693      */
694     public Object unsetAttribute(CrawlerSettings settings, String name)
695             throws AttributeNotFoundException {
696
697         if (settings == globalSettings()) {
698             throw new IllegalArgumentException (
699                 "Not allowed to unset attributes in Crawl Order.");
700         }
701
702         DataContainer data = settings.getData(this);
703         if (data != null && data.containsKey(name)) {
704             // Remove value
705 return data.removeElement(name);
706         }
707
708         // Value not found. Check if we should return null or throw an exception
709 // This method throws an exception if not found.
710 Context context = new Context(settings, null);
711         getDataContainerRecursive(context, name);
712         return null;
713     }
714
715     private DataContainer getOrCreateDataContainer(CrawlerSettings settings)
716         throws InvalidAttributeValueException {
717
718         // Get this ComplexType's data container for the submitted settings
719 DataContainer data = settings.getData(this);
720
721         // If there isn't a container, create one
722 if (data == null) {
723             ComplexType parent = getParent();
724             if (parent == null) {
725                 settings.addTopLevelModule((ModuleType) this);
726             } else {
727                 DataContainer parentData =
728                     settings.getData(parent);
729                 if (parentData == null) {
730                     if (this instanceof ModuleType) {
731                         settings.addTopLevelModule((ModuleType) this);
732                     } else {
733                         settings.addTopLevelModule((ModuleType) parent);
734                         try {
735                             parent.setAttribute(settings, this);
736                         } catch (AttributeNotFoundException e) {
737                             logger.severe(e.getMessage());
738                         }
739                     }
740                 } else {
741                     globalSettings().getData(parent).copyAttributeInfo(
742                         getName(),
743                         parentData);
744                 }
745             }
746
747             // Create fresh DataContainer
748 data = settings.addComplexType(this);
749         }
750
751         // Make sure that the DataContainer references right type
752 if (data.getComplexType() != this) {
753             if (this instanceof ModuleType) {
754                 data = settings.addComplexType(this);
755             }
756         }
757         return data;
758     }
759
760     /* (non-Javadoc)
761      * @see javax.management.DynamicMBean#getAttributes(java.lang.String[])
762      */
763     public AttributeList getAttributes(String [] name) {
764         return null;
765     }
766
767     /* (non-Javadoc)
768      * @see javax.management.DynamicMBean#setAttributes(javax.management.AttributeList)
769      */
770     public AttributeList setAttributes(AttributeList attributes) {
771         return null;
772     }
773
774     /* (non-Javadoc)
775      * @see javax.management.DynamicMBean#invoke(java.lang.String, java.lang.Object[], java.lang.String[])
776      */
777     public Object invoke(String arg0, Object [] arg1, String [] arg2)
778         throws MBeanException , ReflectionException {
779         throw new ReflectionException (
780             new NoSuchMethodException ("No methods to invoke."));
781     }
782
783     /* (non-Javadoc)
784      * @see javax.management.DynamicMBean#getMBeanInfo()
785      */
786     public MBeanInfo getMBeanInfo() {
787         return getMBeanInfo(globalSettings());
788     }
789
790     public MBeanInfo getMBeanInfo(Object context) {
791         MBeanAttributeInfoIterator it = getAttributeInfoIterator(context);
792         MBeanAttributeInfo [] attributes = new MBeanAttributeInfo [it.size()];
793         int index = 0;
794         while(it.hasNext()) {
795             attributes[index++] = (MBeanAttributeInfo ) it.next();
796         }
797
798         MBeanInfo info =
799             new MBeanInfo (getClass().getName(), getDescription(), attributes,
800                 null, null, null);
801         return info;
802     }
803
804     /** Get the effective Attribute info for an element of this type from
805      * a settings object.
806      *
807      * @param settings the settings object for which the Attribute info is
808      * effective.
809      * @param name the name of the element to get the attribute for.
810      * @return the attribute info
811      */
812     public MBeanAttributeInfo getAttributeInfo(CrawlerSettings settings,
813             String name) {
814
815         MBeanAttributeInfo info = null;
816
817         Context context = new Context(settings, null);
818         DataContainer data = getDataContainerRecursive(context);
819         while (data != null && info == null) {
820             info = data.getAttributeInfo(name);
821             if (info == null) {
822                 context.settings = data.getSettings().getParent();
823                 data = getDataContainerRecursive(context);
824             }
825         }
826
827         return info;
828     }
829
830     /** Get the Attribute info for an element of this type from the global
831      * settings.
832      *
833      * @param name the name of the element to get the attribute for.
834      * @return the attribute info
835      */
836     public MBeanAttributeInfo getAttributeInfo(String name) {
837         return getAttributeInfo(globalSettings(), name);
838     }
839
840     /** Get the description of this type
841      *
842      * The description should be suitable for showing in a user interface.
843      *
844      * @return this type's description
845      */
846     public String getDescription() {
847         return description;
848     }
849
850     /** Get the parent of this ComplexType.
851      *
852      * @return the parent of this ComplexType.
853      */
854     public ComplexType getParent() {
855         return parent;
856     }
857
858     /** Set the description of this ComplexType
859      *
860      * The description should be suitable for showing in a user interface.
861      *
862      * @param string the description to set for this type.
863      */
864     public void setDescription(String string) {
865         description = string;
866     }
867
868     /* (non-Javadoc)
869      * @see org.archive.crawler.settings.Type#getDefaultValue()
870      */
871     public Object getDefaultValue() {
872         return this;
873     }
874
875     /** Add a new attribute to the definition of this ComplexType.
876      *
877      * This method can only be called before the ComplexType has been
878      * initialized. This usally means that this method is available for
879      * constructors of subclasses of this class.
880      *
881      * @param type the type to add.
882      * @return the newly added type.
883      */
884     public Type addElementToDefinition(Type type) {
885         if (isInitialized()) {
886             throw new IllegalStateException (
887                     "Elements should only be added to definition in the " +
888                     "constructor.");
889         }
890         if (definitionMap.containsKey(type.getName())) {
891             definition.remove(definitionMap.remove(type.getName()));
892         }
893             
894         definition.add(type);
895         definitionMap.put(type.getName(), type);
896         return type;
897     }
898
899     /** Get an element definition from this complex type.
900      *
901      * This method can only be called before the ComplexType has been
902      * initialized. This usally means that this method is available for
903      * constructors of subclasses of this class.
904      *
905      * @param name name of element to get.
906      * @return the requested element or null if non existent.
907      */
908     public Type getElementFromDefinition(String name) {
909         if (isInitialized()) {
910             throw new IllegalStateException (
911                     "Elements definition can only be accessed in the " +
912                     "constructor.");
913         }
914         return (Type) definitionMap.get(name);
915     }
916
917     /** This method can be overridden in subclasses to do local
918      * initialisation.
919      *
920      * This method is run before the class has been updated with
921      * information from settings files. That implies that if you
922      * call getAttribute inside this method you will only get the
923      * default values.
924      *
925      * @param settings the CrawlerSettings object for which this
926      * complex type is defined.
927      */
928     public void earlyInitialize(CrawlerSettings settings) {
929     }
930
931     /** Returns true if this ComplexType is initialized.
932      *
933      * @return true if this ComplexType is initialized.
934      */
935     public boolean isInitialized() {
936         return initialized;
937     }
938
939     public Object [] getLegalValues() {
940         return null;
941     }
942
943     /** Returns this object.
944      *
945      * This method is implemented to be able to treat the ComplexType as an
946      * subclass of {@link javax.management.Attribute}.
947      *
948      * @return this object.
949      * @see javax.management.Attribute#getValue()
950      */
951     public Object getValue() {
952         return this;
953     }
954
955     class Context {
956         CrawlerSettings settings;
957         UURI uri;
958
959         Context() {
960             settings = null;
961             uri = null;
962         }
963
964         Context(CrawlerSettings settings, UURI uri) {
965             this.settings = settings;
966             this.uri = uri;
967         }
968     }
969
970     /** Get an Iterator over all the attributes in this ComplexType.
971     *
972     * @param context the context for which this set of attributes are valid.
973     * @return an iterator over all the attributes in this map.
974     */
975    public Iterator iterator(Object context) {
976        return new AttributeIterator(context);
977    }
978
979    /** Get an Iterator over all the MBeanAttributeInfo in this ComplexType.
980    *
981    * @param context the context for which this set of MBeanAttributeInfo are valid.
982    * @return an iterator over all the MBeanAttributeInfo in this map.
983    */
984    public MBeanAttributeInfoIterator getAttributeInfoIterator(Object context) {
985        return new MBeanAttributeInfoIterator(context);
986    }
987
988    /**
989     * Iterator over all attributes in a ComplexType.
990     *
991     * @author John Erik Halse
992     */
993    private class AttributeIterator implements Iterator {
994        private Context context;
995        private Stack <Iterator <MBeanAttributeInfo >> attributeStack
996         = new Stack <Iterator <MBeanAttributeInfo >>();
997        private Iterator currentIterator;
998
999        public AttributeIterator(Object ctxt) {
1000           this.context = getSettingsFromObject(ctxt);
1001           Context c = new Context(context.settings, context.uri);
1002           DataContainer data = getDataContainerRecursive(c);
1003           while (data != null) {
1004               this.attributeStack.push(data.getLocalAttributeInfoList().
1005                   iterator());
1006               c.settings = data.getSettings().getParent();
1007               data = getDataContainerRecursive(c);
1008           }
1009
1010           this.currentIterator = (Iterator ) this.attributeStack.pop();
1011       }
1012
1013       public boolean hasNext() {
1014           if (this.currentIterator.hasNext()) {
1015               return true;
1016           }
1017           if (this.attributeStack.isEmpty()) {
1018               return false;
1019           }
1020           this.currentIterator = (Iterator ) this.attributeStack.pop();
1021           return this.currentIterator.hasNext();
1022       }
1023
1024       public Object next() {
1025           hasNext();
1026           try {
1027               MBeanAttributeInfo attInfo = (MBeanAttributeInfo ) this.currentIterator.next();
1028               Object attr = getAttribute(this.context, attInfo.getName());
1029               if (!(attr instanceof Attribute )) {
1030                   attr = new Attribute (attInfo.getName(), attr);
1031               }
1032               return attr;
1033           } catch (AttributeNotFoundException e) {
1034               // This should never happen
1035 e.printStackTrace();
1036               return null;
1037           }
1038       }
1039
1040       public void remove() {
1041           throw new UnsupportedOperationException ();
1042       }
1043   }
1044
1045   /**
1046    * Iterator over all MBeanAttributeInfo for this ComplexType
1047    *
1048    * @author John Erik Halse
1049    */
1050   public class MBeanAttributeInfoIterator implements Iterator {
1051       private Context context;
1052       private Stack <Iterator <MBeanAttributeInfo >> attributeStack
1053        = new Stack <Iterator <MBeanAttributeInfo >>();
1054       private Iterator currentIterator;
1055       private int attributeCount = 0;
1056
1057       public MBeanAttributeInfoIterator(Object ctxt) {
1058           this.context = getSettingsFromObject(ctxt);
1059           //Stack attributeStack = new Stack();
1060 //
1061 DataContainer data = getDataContainerRecursive(context);
1062           while (data != null) {
1063               attributeStack.push(data.getLocalAttributeInfoList().iterator());
1064               attributeCount += data.getLocalAttributeInfoList().size();
1065               context.settings = data.getSettings().getParent();
1066               data = getDataContainerRecursive(context);
1067           }
1068
1069           this.currentIterator = (Iterator ) this.attributeStack.pop();
1070       }
1071
1072       public boolean hasNext() {
1073            if (this.currentIterator.hasNext()) {
1074                return true;
1075            }
1076            if (this.attributeStack.isEmpty()) {
1077                return false;
1078            }
1079            this.currentIterator = (Iterator )this.attributeStack.pop();
1080            return this.currentIterator.hasNext();
1081        }
1082
1083       public Object next() {
1084           hasNext();
1085           MBeanAttributeInfo attInfo = (MBeanAttributeInfo ) this.currentIterator.next();
1086           return attInfo;
1087       }
1088
1089       public void remove() {
1090           throw new UnsupportedOperationException ();
1091       }
1092
1093       public int size() {
1094           return attributeCount;
1095       }
1096   }
1097   
1098   @Override
1099   public String toString() {
1100       // In 1.6, toString goes into infinite loop. Default implementation is
1101 // return getName() + '=' + getValue() but this class returns itself
1102 // for a value on which we do a toString... and around we go. Short
1103 // circuit it here.
1104 return getName() + ": " +
1105           getClass().getName() + "@" + Integer.toHexString(hashCode());
1106   }
1107}

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