BinderHelper


1   //$Id: BinderHelper.java,v 1.3 2005/07/22 22:36:07 epbernard Exp $
2   package org.hibernate.cfg;
3   
4   import java.util.ArrayList  ;
5   import java.util.HashMap  ;
6   import java.util.HashSet  ;
7   import java.util.Iterator  ;
8   import java.util.List  ;
9   import java.util.Map  ;
10  import java.util.Set  ;
11  import java.util.StringTokenizer  ;
12  
13  import org.hibernate.AnnotationException;
14  import org.hibernate.AssertionFailure;
15  import org.hibernate.MappingException;
16  import org.hibernate.cfg.annotations.TableBinder;
17  import org.hibernate.mapping.Collection;
18  import org.hibernate.mapping.Column;
19  import org.hibernate.mapping.Component;
20  import org.hibernate.mapping.PersistentClass;
21  import org.hibernate.mapping.Property;
22  import org.hibernate.mapping.ToOne;
23  import org.hibernate.mapping.Value;
24  import org.hibernate.util.StringHelper;
25  
26  /**
27   * @author Emmanuel Bernard
28   */
29  public class BinderHelper {
30      private BinderHelper() {}
31  
32      /**
33       * create a property copy reusing the same value
34       */
35      public static Property shallowCopy(Property property) {
36          Property clone = new Property();
37          clone.setCascade( property.getCascade() );
38          clone.setInsertable( property.isInsertable() );
39          clone.setLazy( property.isLazy() );
40          clone.setName( property.getName() );
41          clone.setNaturalIdentifier( property.isNaturalIdentifier() );
42          clone.setOptimisticLocked( property.isOptimisticLocked() );
43          clone.setOptional( property.isOptional() );
44          clone.setPersistentClass( property.getPersistentClass() );
45          clone.setPropertyAccessorName( property.getPropertyAccessorName() );
46          clone.setSelectable( property.isSelectable() );
47          clone.setUpdateable( property.isUpdateable() );
48          clone.setValue( property.getValue() );
49          return clone;
50      }
51  
52      public static void createSyntheticPropertyReference(
53              Ejb3JoinColumn[] columns, 
54              PersistentClass referencedEntity,
55              Value value,
56              ExtendedMappings mappings) {
57          if ( columns[0].isImplicit() || StringHelper.isNotEmpty( columns[0].getMappedBy() ) ) return;
58          int fkEnum = Ejb3JoinColumn.checkReferencedColumnsType(columns, referencedEntity);
59          PersistentClass associatedClass = columns[0].getPropertyHolder() == null ? null : columns[0].getPropertyHolder().getPersistentClass();
60          if ( Ejb3JoinColumn.NON_PK_REFERENCE == fkEnum ) {
61              /**
62               * Create a synthetic property to refer to including an
63               * embedded component value containing all the properties
64               * mapped to the referenced columns
65               * We need to shallow copy those properties to mark them
66               * as non insertable / non updatable
67               */
68  
69              String   syntheticPropertyName = new StringBuffer  ("_")
70                      .append( referencedEntity.getEntityName().replace( '.', '_') )
71                      .append("_")
72                      .append( columns[0].getPropertyName() ).toString();
73              //find properties associated to a certain column
74              List  <Property> properties = findPropertiesByColumns(referencedEntity, columns);
75              //create an embeddable component
76              Property synthProp = null;
77              if (properties != null) {
78                  Component embeddedComp = new Component( referencedEntity );
79                  embeddedComp.setEmbedded( true );
80                  embeddedComp.setComponentClassName( embeddedComp.getOwner().getClassName() );
81                  for (Property property : properties) {
82                      Property clone = BinderHelper.shallowCopy(property);
83                      clone.setInsertable( false );
84                      clone.setUpdateable( false );
85                      clone.setNaturalIdentifier( false );
86                      embeddedComp.addProperty( clone );
87                  }
88                  synthProp = new Property();
89                  synthProp.setName(syntheticPropertyName);
90                  //synthProp.setNodeName(syntheticPropertyName);
91                  synthProp.setPersistentClass( referencedEntity );
92                  synthProp.setUpdateable(false);
93                  synthProp.setInsertable(false);
94                  synthProp.setValue(embeddedComp);
95                  synthProp.setPropertyAccessorName( "embedded" );
96                  referencedEntity.addProperty(synthProp);
97                  //make it unique
98                  TableBinder.createUniqueConstraint( embeddedComp );
99              }
100             else {
101                 //TODO use a ToOne type doing a second select
102                 StringBuffer   columnsList = new StringBuffer  ();
103                 for(Ejb3JoinColumn column : columns) {
104                     columnsList.append( column.getReferencedColumn() ).append(", ");
105                 }
106                 throw new AnnotationException("referencedColumnName not mapped to a property is not supported: "
107                     + columnsList.toString() );
108             }
109 
110                 /**
111                  * creating the property ref to the new synthetic property
112                  */
113             if (value instanceof ToOne) {
114                 ( (ToOne) value).setReferencedPropertyName(syntheticPropertyName);
115                 mappings.addUniquePropertyReference(referencedEntity.getEntityName(), syntheticPropertyName);
116             }
117             else if (value instanceof Collection) {
118                 //Collection collection = (Collection) referencedEntity.getProperty( columns[0].getPropertyName() ).getValue();
119                 ( (Collection) value).setReferencedPropertyName( syntheticPropertyName );
120                 //not unique because we could create a mtm wo association table
121                 mappings.addPropertyReference(referencedEntity.getEntityName(), syntheticPropertyName);
122             }
123             else {
124                 throw new AssertionFailure("Do a property ref on an unexpected Value type: "
125                         + value.getClass().getName() );
126             }
127             mappings.addPropertyReferencedAssociation(
128                     associatedClass.getEntityName(),
129                     columns[0].getPropertyName(),
130                     syntheticPropertyName
131             );
132         }
133     }
134 
135 
136     private static List  <Property> findPropertiesByColumns(PersistentClass referencedEntity, Ejb3JoinColumn[] columns) {
137         Map  <Column,Set  <Property>> columnsToProperty = new HashMap  <Column,Set  <Property>>();
138         List  <Column> orderedColumns = new ArrayList  <Column>();
139         for(int index = 0 ; index < columns.length ; index++) {
140             Column column = new Column( columns[index].getReferencedColumn() );
141             orderedColumns.add( column );
142             columnsToProperty.put( column, new HashSet  <Property>() );
143         }
144         Iterator   it = referencedEntity.getPropertyIterator();
145         while ( it.hasNext() ) {
146             Property property = (Property) it.next();
147             Iterator   columnIt = property.getColumnIterator();
148             while ( columnIt.hasNext() ) {
149                 Column column = (Column) columnIt.next();
150                 if ( columnsToProperty.containsKey( column ) ) {
151                     columnsToProperty.get( column ).add( property );
152                 }
153             }
154         }
155         //first naive implementation
156         //only check 1 columns properties
157         //TODO make it smarter by checking correctly ordered multi column properties
158         List  <Property> orderedProperties = new ArrayList  <Property>();
159         for (Column column : orderedColumns) {
160             boolean found = false;
161             for (Property property : columnsToProperty.get( column ) ) {
162                 if (property.getColumnSpan() == 1) {
163                     orderedProperties.add(property);
164                     found = true;
165                     break;
166                 }
167             }
168             if (!found) return null; //have to find it the hard way
169         }
170         return orderedProperties;
171     }
172 
173     public static Property findPropertyByName(PersistentClass associatedClass, String   propertyName) {
174         Property property = null;
175         Property idProperty = associatedClass.getIdentifierProperty();
176         String   idName = idProperty != null ? idProperty.getName() : null;
177         try {
178             if ( propertyName == null
179                     || propertyName.equals( "" )
180                     || propertyName.equals( idName ) ) {
181                 //default to id
182                 property = idProperty;
183             }
184             else {
185                 if ( propertyName.indexOf( idName + "." ) == 0 ) {
186                     property = idProperty;
187                     propertyName = propertyName.substring( idName.length() + 1 );
188                 }
189                 StringTokenizer   st = new StringTokenizer  ( propertyName, ".", false);
190                 while ( st.hasMoreElements() ) {
191                     String   element = (String  ) st.nextElement();
192                     if (property == null) {
193                         property = associatedClass.getProperty( element );
194                     }
195                     else {
196                         if ( ! property.isComposite() ) return null;
197                         property  = ( (Component) property.getValue() ).getProperty(element);
198                     }
199                 }
200             }
201         }
202         catch (MappingException e) {
203             return null;
204         }
205         return property;
206     }
207 }
208
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