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1   /*
2    * $Id:AbstractMuleBeanDefinitionParser.java 5187 2007-02-16 18:00:42Z rossmason $
3    * --------------------------------------------------------------------------------------
4    * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
5    *
6    * The software in this package is published under the terms of the CPAL v1.0
7    * license, a copy of which has been included with this distribution in the
8    * LICENSE.txt file.
9    */
10  package org.mule.config.spring.parsers;
11  
12  import org.mule.api.MuleContext;
13  import org.mule.api.component.Component;
14  import org.mule.api.config.MuleProperties;
15  import org.mule.api.lifecycle.Disposable;
16  import org.mule.api.lifecycle.Initialisable;
17  import org.mule.api.routing.OutboundRouter;
18  import org.mule.api.routing.OutboundRouterCollection;
19  import org.mule.api.source.MessageSource;
20  import org.mule.config.spring.MuleHierarchicalBeanDefinitionParserDelegate;
21  import org.mule.config.spring.parsers.assembly.BeanAssembler;
22  import org.mule.config.spring.parsers.assembly.BeanAssemblerFactory;
23  import org.mule.config.spring.parsers.assembly.DefaultBeanAssemblerFactory;
24  import org.mule.config.spring.parsers.assembly.configuration.ReusablePropertyConfiguration;
25  import org.mule.config.spring.parsers.assembly.configuration.ValueMap;
26  import org.mule.config.spring.parsers.generic.AutoIdUtils;
27  import org.mule.exception.AbstractExceptionListener;
28  import org.mule.util.ClassUtils;
29  import org.mule.util.StringUtils;
30  import org.mule.util.XMLUtils;
31  
32  import java.util.HashSet;
33  import java.util.Iterator;
34  import java.util.LinkedList;
35  import java.util.List;
36  import java.util.Map;
37  import java.util.Set;
38  
39  import org.apache.commons.logging.Log;
40  import org.apache.commons.logging.LogFactory;
41  import org.springframework.beans.factory.BeanDefinitionStoreException;
42  import org.springframework.beans.factory.config.BeanDefinition;
43  import org.springframework.beans.factory.support.AbstractBeanDefinition;
44  import org.springframework.beans.factory.support.BeanDefinitionBuilder;
45  import org.springframework.beans.factory.support.BeanDefinitionRegistry;
46  import org.springframework.beans.factory.xml.AbstractBeanDefinitionParser;
47  import org.springframework.beans.factory.xml.ParserContext;
48  import org.w3c.dom.Attr;
49  import org.w3c.dom.Element;
50  import org.w3c.dom.NamedNodeMap;
51  
52  /**
53   * This parser extends the Spring provided {@link AbstractBeanDefinitionParser} to provide additional features for
54   * consistently customising bean representations for Mule bean definition parsers.  Most custom bean definition parsers
55   * in Mule will use this base class. The following enhancements are made -
56   *
57   * <ol>
58   * <li>A property name which ends with the suffix "-ref" is assumed to be a reference to another bean.
59   * Alternatively, a property can be explicitly registered as a bean reference via registerBeanReference()
60   *
61   * <p>For example,
62   * <code> &lt;bpm:connector bpms-ref=&quot;testBpms&quot;/&gt;</code>
63   * will automatically set a property "bpms" on the connector to reference a bean named "testBpms"
64   * </p></li>
65   *
66   * <li>Attribute mappings can be registered to control how an attribute name in Mule Xml maps to the bean name in the
67   * object being created.
68   *
69   * <p>For example -
70   * <code>addAlias("poolExhaustedAction", "poolExhaustedActionString");</code>
71   * Maps the 'poolExhaustedAction' to the 'poolExhaustedActionString' property on the bean being created.
72   * </p></li>
73   *
74   * <li>Value Mappings can be used to map key value pairs from selection lists in the XML schema to property values on the
75   * bean being created. These are a comma-separated list of key=value pairs.
76   *
77   * <p>For example -
78   * <code>addMapping("action", "NONE=0,ALWAYS_BEGIN=1,BEGIN_OR_JOIN=2,JOIN_IF_POSSIBLE=3");</code>
79   * The first argument is the bean name to set, the second argument is the set of possible key=value pairs
80   * </p></li>
81   *
82   * <li>Provides an automatic way of setting the 'init-method' and 'destroy-method' for this object. This will then automatically
83   * wire the bean into the lifecycle of the Application context.</li>
84   *
85   * <li>The 'singleton' property provides a fixed way to make sure the bean is always a singleton or not.</li>
86   *
87   * <li>Collections will be automatically created and extended if the setter matches "property+s".</li>
88   * </ol>
89   *
90   * <p>Note that this class is not multi-thread safe.  The internal state is reset before each "use"
91   * by {@link #preProcess(org.w3c.dom.Element)} which assumes sequential access.</p>
92   *
93   * @see  AbstractBeanDefinitionParser
94   */
95  public abstract class AbstractMuleBeanDefinitionParser extends AbstractBeanDefinitionParser
96      implements MuleDefinitionParser
97  {
98  
99      public static final String ROOT_ELEMENT = "mule";
100     public static final String ATTRIBUTE_ID = "id";
101     public static final String ATTRIBUTE_NAME = "name";
102     public static final String ATTRIBUTE_CLASS = "class";
103     public static final String ATTRIBUTE_REF = "ref";
104     public static final String ATTRIBUTE_REFS = "refs";
105     public static final String ATTRIBUTE_REF_SUFFIX = "-" + ATTRIBUTE_REF;
106     public static final String ATTRIBUTE_REFS_SUFFIX = "-" + ATTRIBUTE_REFS;
107 
108     /**
109      * logger used by this class
110      */
111     protected transient Log logger = LogFactory.getLog(getClass());
112 
113     private BeanAssemblerFactory beanAssemblerFactory = new DefaultBeanAssemblerFactory();
114     protected ReusablePropertyConfiguration beanPropertyConfiguration = new ReusablePropertyConfiguration();
115     private ParserContext parserContext;
116     private BeanDefinitionRegistry registry;
117     private LinkedList preProcessors = new LinkedList();
118     private List postProcessors = new LinkedList();
119     private Set beanAttributes = new HashSet();
120     // By default Mule objects are not singletons
121     protected boolean singleton = false;
122 
123     /** Allow the bean class to be set explicitly via the "class" attribute. */
124     private boolean allowClassAttribute = true;
125     private Class classConstraint = null;
126     
127     private String deprecationWarning;
128 
129     public AbstractMuleBeanDefinitionParser()
130     {
131         addIgnored(ATTRIBUTE_ID);
132         addBeanFlag(MuleHierarchicalBeanDefinitionParserDelegate.MULE_FORCE_RECURSE);
133     }
134 
135     public MuleDefinitionParserConfiguration addReference(String propertyName)
136     {
137         beanPropertyConfiguration.addReference(propertyName);
138         return this;
139     }
140 
141     public MuleDefinitionParserConfiguration addMapping(String propertyName, Map mappings)
142     {
143         beanPropertyConfiguration.addMapping(propertyName, mappings);
144         return this;
145     }
146 
147     public MuleDefinitionParserConfiguration addMapping(String propertyName, String mappings)
148     {
149         beanPropertyConfiguration.addMapping(propertyName, mappings);
150         return this;
151     }
152 
153     public MuleDefinitionParserConfiguration addMapping(String propertyName, ValueMap mappings)
154     {
155         beanPropertyConfiguration.addMapping(propertyName, mappings);
156         return this;
157     }
158 
159     /**
160      * @param alias The attribute name
161      * @param propertyName The bean property name
162      * @return This instance, allowing chaining during use, avoiding subclasses
163      */
164     public MuleDefinitionParserConfiguration addAlias(String alias, String propertyName)
165     {
166         beanPropertyConfiguration.addAlias(alias, propertyName);
167         return this;
168     }
169 
170     /**
171      * @param propertyName Property that is a collection
172      * @return This instance, allowing chaining during use, avoiding subclasses
173      */
174     public MuleDefinitionParserConfiguration addCollection(String propertyName)
175     {
176         beanPropertyConfiguration.addCollection(propertyName);
177         return this;
178     }
179 
180     /**
181      * @param propertyName Property that is to be ignored
182      * @return This instance, allowing chaining during use, avoiding subclasses
183      */
184     public MuleDefinitionParserConfiguration addIgnored(String propertyName)
185     {
186         beanPropertyConfiguration.addIgnored(propertyName);
187         return this;
188     }
189 
190     public MuleDefinitionParserConfiguration removeIgnored(String propertyName)
191     {
192         beanPropertyConfiguration.removeIgnored(propertyName);
193         return this;
194     }
195 
196     public MuleDefinitionParserConfiguration setIgnoredDefault(boolean ignoreAll)
197     {
198         beanPropertyConfiguration.setIgnoredDefault(ignoreAll);
199         return this;
200     }
201 
202     protected void processProperty(Attr attribute, BeanAssembler assembler)
203     {
204         assembler.extendBean(attribute);
205     }
206 
207     /**
208      * Hook method that derived classes can implement to inspect/change a
209      * bean definition after parsing is complete.
210      *
211      * @param assembler the parsed (and probably totally defined) bean definition being built
212      * @param element   the XML element that was the source of the bean definition's metadata
213      */
214     protected void postProcess(ParserContext context, BeanAssembler assembler, Element element)
215     {
216         element.setAttribute(ATTRIBUTE_NAME, getBeanName(element));
217         for (Iterator attributes = beanAttributes.iterator(); attributes.hasNext();)
218         {
219             assembler.setBeanFlag((String) attributes.next());
220         }
221         for (Iterator processes = postProcessors.iterator(); processes.hasNext();)
222         {
223             ((PostProcessor) processes.next()).postProcess(context, assembler, element);
224         }
225     }
226 
227     /**
228      * Hook method that derived classes can implement to modify internal state before processing.
229      *
230      * Here we make sure that the internal property configuration state is reset to the
231      * initial configuration for each element (it may be modified by the BeanAssembler)
232      * and that other mutable instance variables are cleared.
233      */
234     protected void preProcess(Element element)
235     {
236         parserContext = null;
237         registry = null;
238         beanPropertyConfiguration.reset();
239         Iterator processes = preProcessors.iterator();
240         while (processes.hasNext())
241         {
242             ((PreProcessor) processes.next()).preProcess(beanPropertyConfiguration, element);
243         }
244     }
245 
246     /**
247      * Creates a {@link BeanDefinitionBuilder} instance for the
248      * {@link #getBeanClass bean Class} and passes it to the
249      * {@link #doParse} strategy method.
250      *
251      * @param element       the element that is to be parsed into a single BeanDefinition
252      * @param parserContext the object encapsulating the current state of the parsing process
253      * @return the BeanDefinition resulting from the parsing of the supplied {@link Element}
254      * @throws IllegalStateException if the bean {@link Class} returned from
255      *                               {@link #getBeanClass(org.w3c.dom.Element)} is <code>null</code>
256      * @see #doParse
257      */
258     @Override
259     protected AbstractBeanDefinition parseInternal(Element element, ParserContext parserContext)
260     {
261         preProcess(element);
262         setParserContext(parserContext);
263         setRegistry(parserContext.getRegistry());
264         checkElementNameUnique(element);
265         Class beanClass = getClassInternal(element);
266         BeanDefinitionBuilder builder = createBeanDefinitionBuilder(element, beanClass);
267         builder.getRawBeanDefinition().setSource(parserContext.extractSource(element));
268         builder.setScope(isSingleton() ? BeanDefinition.SCOPE_SINGLETON : BeanDefinition.SCOPE_PROTOTYPE);
269 
270         // Marker for MULE-4813
271         // We don't want lifcycle for the following from spring
272         if (!Component.class.isAssignableFrom(beanClass) && !MessageSource.class.isAssignableFrom(beanClass)
273             && !OutboundRouterCollection.class.isAssignableFrom(beanClass)
274             && !OutboundRouter.class.isAssignableFrom(beanClass)
275             && !AbstractExceptionListener.class.isAssignableFrom(beanClass))
276         {
277             if (Initialisable.class.isAssignableFrom(beanClass))
278             {
279                 builder.setInitMethodName(Initialisable.PHASE_NAME);
280             }
281 
282             if (Disposable.class.isAssignableFrom(beanClass))
283             {
284                 builder.setDestroyMethodName(Disposable.PHASE_NAME);
285             }
286         }
287 
288         if (parserContext.isNested())
289         {
290             // Inner bean definition must receive same singleton status as containing bean.
291             builder.setScope(parserContext.getContainingBeanDefinition().isSingleton() 
292                 ? BeanDefinition.SCOPE_SINGLETON : BeanDefinition.SCOPE_PROTOTYPE);
293         }
294 
295         doParse(element, parserContext, builder);
296         return builder.getBeanDefinition();
297     }
298 
299     protected void setRegistry(BeanDefinitionRegistry registry)
300     {
301         this.registry = registry;
302     }
303 
304     protected BeanDefinitionRegistry getRegistry()
305     {
306         if (null == registry)
307         {
308             throw new IllegalStateException("Set the registry from within doParse");
309         }
310         return registry;
311     }
312 
313     protected void checkElementNameUnique(Element element)
314     {
315         if (null != element.getAttributeNode(ATTRIBUTE_NAME))
316         {
317             String name = element.getAttribute(ATTRIBUTE_NAME);
318             if (getRegistry().containsBeanDefinition(name))
319             {
320                 throw new IllegalArgumentException("A service named " + name + " already exists.");
321             }
322         }
323     }
324 
325     protected BeanDefinitionBuilder createBeanDefinitionBuilder(Element element, Class beanClass)
326     {
327         BeanDefinitionBuilder builder = BeanDefinitionBuilder.rootBeanDefinition(beanClass);
328         // If a constructor with a single MuleContext argument is available then use it.
329         if (ClassUtils.getConstructor(beanClass, new Class[]{MuleContext.class}, true) != null)
330         {
331             builder.addConstructorArgReference(MuleProperties.OBJECT_MULE_CONTEXT);
332         }
333         return builder;
334     }
335 
336     protected Class getClassInternal(Element element)
337     {
338         Class beanClass = null;
339         if (isAllowClassAttribute())
340         {
341             beanClass = getBeanClassFromAttribute(element);
342         }
343         if (beanClass == null)
344         {
345             beanClass = getBeanClass(element);
346         }
347         if (null != beanClass && null != classConstraint && !classConstraint.isAssignableFrom(beanClass))
348         {
349             throw new IllegalStateException(beanClass + " not a subclass of " + classConstraint +
350                     " for " + XMLUtils.elementToString(element));
351         }
352         if (null == beanClass)
353         {
354             throw new IllegalStateException("No class for element " + XMLUtils.elementToString(element));
355         }
356         return beanClass;
357     }
358 
359     /**
360      * Determine the bean class corresponding to the supplied {@link Element} based on an
361      * explicit "class" attribute.
362      *
363      * @param element the <code>Element</code> that is being parsed
364      * @return the {@link Class} of the bean that is being defined via parsing the supplied <code>Element</code>
365      *         (must <b>not</b> be <code>null</code>)
366      * @see #parseInternal(org.w3c.dom.Element,ParserContext)
367      */
368     protected Class<?> getBeanClassFromAttribute(Element element)
369     {
370         String att = beanPropertyConfiguration.getAttributeAlias(ATTRIBUTE_CLASS);
371         String className = element.getAttribute(att);
372         Class<?> clazz = null;
373         if (StringUtils.isNotBlank(className))
374         {
375             try
376             {
377                 element.removeAttribute(att);
378                 clazz = ClassUtils.loadClass(className, getClass());
379             }
380             catch (ClassNotFoundException e)
381             {
382                 logger.error("could not load class: " + className, e);
383             }
384         }
385         return clazz;
386     }
387 
388     /**
389      * Determine the bean class corresponding to the supplied {@link Element}.
390      *
391      * @param element the <code>Element</code> that is being parsed
392      * @return the {@link Class} of the bean that is being defined via parsing the supplied <code>Element</code>
393      *         (must <b>not</b> be <code>null</code>)
394      * @see #parseInternal(org.w3c.dom.Element,ParserContext)
395      */
396     protected abstract Class<?> getBeanClass(Element element);
397 
398     /**
399      * Parse the supplied {@link Element} and populate the supplied
400      * {@link BeanDefinitionBuilder} as required.
401      * <p>The default implementation delegates to the <code>doParse</code>
402      * version without ParserContext argument.
403      *
404      * @param element       the XML element being parsed
405      * @param parserContext the object encapsulating the current state of the parsing process
406      * @param builder       used to define the <code>BeanDefinition</code>
407      */
408     protected void doParse(Element element, ParserContext parserContext, BeanDefinitionBuilder builder)
409     {
410         if (deprecationWarning != null && logger.isWarnEnabled())
411         {
412             logger.warn("Schema warning: Use of element <" + element.getLocalName() + "> is deprecated.  " + deprecationWarning);
413         }
414         
415         BeanAssembler assembler = getBeanAssembler(element, builder);
416         NamedNodeMap attributes = element.getAttributes();
417         for (int x = 0; x < attributes.getLength(); x++)
418         {
419             Attr attribute = (Attr) attributes.item(x);
420             processProperty(attribute, assembler);
421         }
422         postProcess(getParserContext(), assembler, element);
423     }
424 
425     @Override
426     protected String resolveId(Element element, AbstractBeanDefinition definition, ParserContext parserContext) throws BeanDefinitionStoreException
427     {
428         return getBeanName(element);
429     }
430 
431     protected boolean isSingleton()
432     {
433         return singleton;
434     }
435 
436     /**
437      * Restricted use - does not include a target.
438      * If possible, use {@link org.mule.config.spring.parsers.AbstractHierarchicalDefinitionParser#getBeanAssembler(org.w3c.dom.Element, org.springframework.beans.factory.support.BeanDefinitionBuilder)}
439      *
440      * @param bean The bean being constructed
441      * @return An assembler that automates Mule-specific logic for bean construction
442      */
443     protected BeanAssembler getBeanAssembler(Element element, BeanDefinitionBuilder bean)
444     {
445         return getBeanAssemblerFactory().newBeanAssembler(
446                 beanPropertyConfiguration, bean, beanPropertyConfiguration, null);
447     }
448 
449     protected boolean isAllowClassAttribute()
450     {
451         return allowClassAttribute;
452     }
453 
454     protected void setAllowClassAttribute(boolean allowClassAttribute)
455     {
456         this.allowClassAttribute = allowClassAttribute;
457     }
458 
459     protected Class getClassConstraint()
460     {
461         return classConstraint;
462     }
463 
464     protected void setClassConstraint(Class classConstraint)
465     {
466         this.classConstraint = classConstraint;
467     }
468 
469     protected ParserContext getParserContext()
470     {
471         return parserContext;
472     }
473 
474     protected void setParserContext(ParserContext parserContext)
475     {
476         this.parserContext = parserContext;
477     }
478 
479     /**
480      * @param element The element to test
481      * @return true if the element's parent is <mule> or similar
482      */
483     protected boolean isTopLevel(Element element)
484     {
485         return element.getParentNode().getLocalName().equals(ROOT_ELEMENT);
486     }
487 
488     public AbstractBeanDefinition muleParse(Element element, ParserContext parserContext)
489     {
490         return parseInternal(element, parserContext);
491     }
492 
493     public MuleDefinitionParserConfiguration registerPreProcessor(PreProcessor preProcessor)
494     {
495         preProcessors.addFirst(preProcessor);
496         return this;
497     }
498 
499     public MuleDefinitionParserConfiguration registerPostProcessor(PostProcessor postProcessor)
500     {
501         postProcessors.add(postProcessor);
502         return this;
503     }
504 
505     public BeanAssemblerFactory getBeanAssemblerFactory()
506     {
507         return beanAssemblerFactory;
508     }
509 
510     public void setBeanAssemblerFactory(BeanAssemblerFactory beanAssemblerFactory)
511     {
512         this.beanAssemblerFactory = beanAssemblerFactory;
513     }
514 
515     public String getBeanName(Element element)
516     {
517         return AutoIdUtils.getUniqueName(element, "mule-bean");
518     }
519 
520     public MuleDefinitionParserConfiguration addBeanFlag(String flag)
521     {
522         beanAttributes.add(flag);
523         return this;
524     }
525 
526     public void setDeprecationWarning(String deprecationWarning)
527     {
528         this.deprecationWarning = deprecationWarning;
529     }
530 }