Class


1   /**
2    * JORM: an implementation of a generic mapping system for persistent Java
3    *       objects. Two mapping are supported: to RDBMS and to binary files.
4    * Copyright (C) 2001-2003 France Telecom R&D - INRIA
5    *
6    * This library is free software; you can redistribute it and/or
7    * modify it under the terms of the GNU Lesser General Public
8    * License as published by the Free Software Foundation; either
9    * version 2 of the License, or (at your option) any later version.
10   *
11   * This library is distributed in the hope that it will be useful,
12   * but WITHOUT ANY WARRANTY; without even the implied warranty of
13   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14   * Lesser General Public License for more details.
15   *
16   * You should have received a copy of the GNU Lesser General Public
17   * License along with this library; if not, write to the Free Software
18   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
19   *
20   * Contact: jorm-team@objectweb.org
21   *
22   */
23  
24  package org.objectweb.jorm.metainfo.api;
25  
26  import java.util.Collection  ;
27  import java.util.List  ;
28  
29  import org.objectweb.jorm.type.api.PType;
30  import org.objectweb.medor.expression.api.Expression;
31  import org.objectweb.medor.expression.api.ExpressionException;
32  
33  /**
34   * A Class interface defines methods to describe a Class meta object.
35   * A Class is composed by a set of fields (primitive, reference class or
36   * reference generic class), a set of inherited classes, a mapping class,
37   * can be abstract or not and has a name.
38   * @author  X. Spengler
39   */
40  public interface Class extends MetaObject {
41      /**
42       * Allows to retrieve the file name of this class MO.
43       * @return  The file name.
44       */
45      String   getFileName();
46  
47      /**
48       * Allows to assign the file name of this class MO.
49       * @param filename  The file name.
50       */
51      void setFileName(String   filename);
52  
53      /**
54       * Allows to know if the current class is an abstract class or not.
55       *
56       * @return  true, if the current class is an abstract class, and false,
57       *          if the current class is not abstract
58       */
59      boolean isAbstract();
60  
61      void setAbstract(boolean isAbstract);
62  
63      /**
64       * Allows to know the name of the current class object.
65       * @return  the string representation of the class name
66       */
67      String   getName();
68  
69      /**
70       * Gets the fully qualified name (including the package name) associated
71       * with this class.
72       * @return  the string representation of the fully qualified class name
73       */
74      String   getFQName();
75  
76      /**
77       * Allows to obtain an existing Field.
78       * A TypedElement is a class field, and this method finds a field with its
79       * name (fieldName). This method is a generic method to return a
80       * TypedElement object.
81       *
82       * @param fieldName the name of the class field
83       * @return  a field object. If the field does not exist, null is returned.
84       */
85      TypedElement getTypedElement(String   fieldName);
86  
87      /**
88       * Removes a typed element.
89       * @param fieldName is the name of the field to be removed
90       * @return the removed element or null if the field has not been found.
91       */
92      TypedElement removeTypedElement(String   fieldName);
93  
94      /**
95       * Creates a new NameDef object for the current Class object.
96       * Here we can define if the namedef is defined outside jorm or not.
97       * In the case where the namedef is already defined for the current class,
98       * the old one is used and returned.
99       * associated.
100      * @return  a new object used to describe the PName projection for
101      *          the current Class
102      */
103     NameDef createNameDef();
104 
105     /**
106      * Creates an hiddenfield for the current Class object.
107      * An hidden field is used to map the pname of the class or the pname of a ref field.
108      * An hidden field is a scalarfield.
109      *
110      * @param fieldname     the name of the hiddenfield
111      * @param type          the ptype of the hiddenfield
112      * @param size is the
113      * @return  a new scalarfield object used to describe the hiddenfield
114      */
115 
116     ScalarField createHiddenField(String   fieldname, PType type, int size, int scale);
117 
118     /**
119      * @return a collection of hidden field of the class WITHOUT inherited
120      * fields.
121      */
122     Collection   getHiddenFields() ;
123 
124     /**
125      * @return a collection of hidden field of the class including inherited
126      * fields.
127      */
128     Collection   getAllHiddenFields() ;
129 
130     /**
131      * Retrieve the hiddenfield identified by its name in the current class.
132      * @param fieldname the name of the hiddenfield.
133      * @return the scalarfield object describing the hiddenfield or null if the field does not exist in the class.
134      */
135     ScalarField getHiddenField(String   fieldname);
136 
137 
138     /**
139      * Returns a NameDef object from a given mapperName and mappingName.
140      * If the namedef does not exist, null is returned.
141      *
142      * @param projectName   the name of the class project
143      * @return  an existing namedef object if exists, either null
144      */
145     NameDef getNameDef(String   projectName);
146 
147     /**
148      * @return a collection of NameDef object
149      */
150     Collection   getNameDefs();
151 
152     /**
153      * @return the filter expression (Medor expression) permitting to known if
154      * instance of the parent class is in fact an instance of the current
155      * persistent class. The filter uses the field name (composite field in case
156      * of a composite or the field class name). If the current class has no
157      * parent, then this method return null;
158      */
159     Expression  getInheritanceFilter(NameDef nd) throws ExpressionException;
160 
161     /**
162      * @return the key matching to the current class. This value is the result
163      * of the inheritance filter evaluation.
164      */
165     Object   getInheritanceNamingKey(NameDef nd);
166 
167     void setInheritanceNamingKey(NameDef nd, Object   key);
168 
169     /**
170      * @param filter is the filter expression (Medor expression) permitting to
171      * known if instance of the parent class is in fact an instance of the
172      * current persistent class. The filter uses the field name (composite field
173      * in case of a composite or the field class name).
174      */
175     void setInheritanceFilter(NameDef nd, Expression filter);
176 
177     /**
178      * @param filter is the filter expression (Medor expression as string)
179      * permitting to known if instance of the parent class is in fact an
180      * instance of the current persistent class. The filter uses the field name
181      * (composite field in case of a composite or the field class name).
182      */
183     void setInheritanceFilter(NameDef nd, String   filter);
184 
185 
186     /**
187      * Allows to obtain a new PrimitiveElement from a class field name an its
188      * type.
189      * A PrimitiveElement is a Class field. If the class field already exists,
190      * it is returned.
191      *
192      * @param fieldName the name of the primitive field
193      * @param type      the PType of the primitive field
194      * @return  a new PrimitiveElement object, or the existing one if already
195      *          defined
196      */
197     PrimitiveElement createPrimitiveElement(String   fieldName, PType type, int size, int scale);
198 
199     /**
200      * Defines the value of a constant PrimitiveElement, defined either in the
201      * current class or in one of its ancestors.
202      * <p>The constant value is represented by a String.
203      *
204      * @param fieldName the existing PrimitiveElement
205      * @param cv    the constant value
206      */
207     void setConstantValue(String   fieldName, String   cv);
208 
209     /**
210      * Obtains the value of a constant PrimitiveElement, defined either in the
211      * current class or in one of its ancestors.
212      * <p>The constant value is represented by a String.
213      *
214      * @param fieldName the existing PrimitiveElement
215      * @return the constant value as a String
216      */
217     String   getConstantValue(String   fieldName);
218 
219     /**
220      * Allows to obtain a new ClassRef from a field name an its class.
221      * A ClassRef object is a field which is represented by a reference to a
222      * Class. If the field already exists, it is returned.
223      *
224      * @param fieldName the name of the field
225      * @param class_    the class meta-object which represents the reference of
226      *                  the field
227      * @return  a new ClassRef object, or the existing one if already defined
228      */
229     ClassRef createClassRef(String   fieldName, Class   class_);
230 
231     /**
232      * Allows to obtain a new GenClassRef from a field name an its generic
233      * class.
234      * A GenClassRef object is a field which is represented by a
235      * reference to a generic class. If the field already exists,
236      * it is returned.
237      *
238      * @param fieldName the name of the field
239      * @param genName   the GenClass object which represents the reference of
240      *                  the field
241      * @return  a new GenClassRef object, or the existing one if already
242      *          defined
243      */
244     GenClassRef createGenClassRef(String   fieldName, String   genName);
245 
246     /**
247      * Returns an iterator on existing class fields.
248      * If no field is defined, an empty iterator is returned.
249      * This iterator contains PrimitiveElements, ClassRef and GenClassRef
250      * objects. The top level object is TypedElement.
251      *
252      * @return  an iterator on fields, or null if there is no defined field
253      */
254     Collection   getFields();
255 
256     /**
257      * Returns an iterator on existing class fields + fields from super classes.
258      * This iterator contains PrimitiveElement, ClassRef and GenClassRef
259      * objects.
260      *
261      * @return  an iterator on all defined fields, plus fields from super
262      */
263     Collection   getAllFields() ;
264 
265     /**
266      * Allows us to obtain all classes derived from the current class object.
267      * This collection contains Class objects. In the case where there is no
268      * derived class, an empty collection is returned.
269      *
270      * @return  a collection on derived classes (Class objets). If no object
271      *          exists, an empty collection is returned.
272      */
273     Collection   getSubClasses();
274 
275     /**
276      * Retrieves the collection of super classes
277      * @return   a collection of Class meta objects.
278      */
279     Collection   getSuperClasses();
280 
281     /**
282      * Retrieves a super class whith its name.
283      * @param fqcn is the fully qualified class name of the super class
284      * @return a Class meta object instance if the specified class name is a
285      * super class of the current class. A null value if the specified class name is
286      * not a super class of the current class.
287      */
288     Class   getSuperClass(String   fqcn);
289 
290     /**
291      * Adds a new inherited class to the list of the inherited classes for the
292      * current class object.
293      * If the class already exists, nothing is done.
294      *
295      * @param class_    the inherited class to add to inherited classes list
296      */
297     void addSuperClass(Class   class_);
298 
299     /**
300      * Adds a new class to the list of the derived classes for the
301      * current class object.
302      * If the class already exists, nothing is done.
303      *
304      * @param class_    the inherited class to add to inherited classes list
305      */
306     void addSubClass(Class   class_);
307 
308     /**
309      * Returns the number of inherited classes for the current Class object.
310      *
311      * @return  the number of inherited classes
312      */
313     int getInheritedClassNumber();
314 
315     /**
316      * @return the PType of the persistent class
317      */
318     PType getPType();
319 
320     /**
321      * Returns the number of fields which are references to classes.
322      *
323      * @return  the number of fieldRef
324      */
325     int getFieldRefNumber();
326 
327     /**
328      * Returns a ClassProject object.
329      *
330      * @param  projectName       a project name.
331      * @return a ClassProject object.
332      */
333     ClassProject getClassProject(String   projectName);
334 
335     /**
336      * Returns a ClassMapping object.
337      *
338      * @param  projectName      a project name,
339      *         mappername       a mapper name.
340      * @return a ClassMapping object.
341      */
342     public ClassMapping getClassMapping(String   projectName, String   mapperName);
343 
344     /**
345      * Returns a collection of ClassProject objects.
346      * @return   a collection.
347      */
348     Collection   getClassProjects();
349 
350     /**
351      * Adds a ClassProject object.
352      *
353      * @param  projectName       a project name,
354      *         classProject     a ClassProject object.
355      */
356     void addClassProject(String   projectName, ClassProject classProject);
357 
358     /**
359      * Creates a new ClassProject object.
360      *
361      * @param projectName   the name of the project.
362      * @return a new ClassProject object, or an existing one.
363      */
364     ClassProject createClassProject(String   projectName);
365 
366     /**
367      * Removes a ClassProject instance.
368      * @param projectname is the name of removed ClassProject
369      * @return The removed ClassProject
370      */
371     ClassProject removeClassProject(String   projectname);
372 
373     /**
374      * Returns only the top ancestors.
375      */
376     List   getAncestors();
377 
378     /**
379      * Return all the ancestors in the inheritance graph.
380      */
381     List   getAllAncestors();
382     
383     /**
384      * Returns true if the class is polymorphic, i.e. it has subclasses or
385      * superclasses
386      * @return true if the class is polymorphic
387      */
388     boolean isPolymorphic();
389 
390     /**
391      * Return true if the KFPNC has to be generated.
392      * Else, return false.
393      */
394     boolean generateKFPNC() throws ExpressionException;
395     
396     /**
397      * Return true if one element of the expression exp is not part of the namedef.
398      * Else, return false.
399      */
400     public boolean detectFilterElementNotInPK(Expression exp, NameDef nd) 
401                     throws ExpressionException;
402 }
403
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