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Java > Open Source Codes > org > apache > cayenne > access > DataDomainFlushObserver


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19
20 package org.apache.cayenne.access;
21
22 import java.util.Iterator JavaDoc;
23 import java.util.List JavaDoc;
24
25 import org.apache.cayenne.CayenneException;
26 import org.apache.cayenne.CayenneRuntimeException;
27 import org.apache.cayenne.DataRow;
28 import org.apache.cayenne.ObjectId;
29 import org.apache.cayenne.map.DbAttribute;
30 import org.apache.cayenne.query.BatchQuery;
31 import org.apache.cayenne.query.InsertBatchQuery;
32 import org.apache.cayenne.query.Query;
33 import org.apache.cayenne.util.Util;
34
35 /**
36  * Used as an observer for DataContext commit operations.
37  *
38  * @since 1.2
39  * @author Andrus Adamchik
40  */
41 class DataDomainFlushObserver implements OperationObserver {
42
43     public void nextQueryException(Query query, Exception JavaDoc ex) {
44         throw new CayenneRuntimeException("Raising from query exception.", Util
45                 .unwindException(ex));
46     }
47
48     public void nextGlobalException(Exception JavaDoc ex) {
49         throw new CayenneRuntimeException(
50                 "Raising from underlyingQueryEngine exception.",
51                 Util.unwindException(ex));
52     }
53
54     /**
55      * Processes generated keys.
56      *
57      * @since 1.2
58      */
59     public void nextGeneratedDataRows(Query query, ResultIterator keysIterator) {
60
61         // read and close the iterator before doing anything else
62 List JavaDoc keys;
63         try {
64             keys = keysIterator.dataRows(true);
65         }
66         catch (CayenneException ex) {
67             throw new CayenneRuntimeException("Error reading primary key", Util
68                     .unwindException(ex));
69         }
70
71         if (!(query instanceof InsertBatchQuery)) {
72             throw new CayenneRuntimeException(
73                     "Generated keys only supported for InsertBatchQuery, instead got "
74                             + query);
75         }
76
77         BatchQuery batch = (BatchQuery) query;
78
79         ObjectId id = batch.getObjectId();
80         if (id == null || !id.isTemporary()) {
81             // why would this happen?
82 return;
83         }
84
85         if (keys.size() != 1) {
86             throw new CayenneRuntimeException(
87                     "One and only one PK row is expected, instead got " + keys.size());
88         }
89
90         DataRow key = (DataRow) keys.get(0);
91
92         // empty key?
93 if (key.size() == 0) {
94             throw new CayenneRuntimeException("Empty key generated.");
95         }
96
97         // determine DbAttribute name...
98
99         // As of now (01/2005) all tested drivers don't provide decent descriptors of
100 // identity result sets, so a data row will contain garbage labels. Also most
101 // DBs only support one autogenerated key per table... So here we will have to
102 // infer the key name and currently will only support a single column...
103 if (key.size() > 1) {
104             throw new CayenneRuntimeException(
105                     "Only a single column autogenerated PK is supported. "
106                             + "Generated key: "
107                             + key);
108         }
109
110         Iterator JavaDoc it = batch.getDbEntity().getGeneratedAttributes().iterator();
111         while (it.hasNext()) {
112             DbAttribute attribute = (DbAttribute) it.next();
113
114             // batch can have generated attributes that are not PKs, e.g. columns with
115 // DB DEFAULT values. Ignore those.
116 if (attribute.isPrimaryKey()) {
117                 Object JavaDoc value = key.values().iterator().next();
118
119                 // I guess we should override any existing value,
120 // as generated key is the latest thing that exists in the DB.
121 id.getReplacementIdMap().put(attribute.getName(), value);
122                 break;
123             }
124         }
125     }
126
127     public void nextBatchCount(Query query, int[] resultCount) {
128     }
129
130     public void nextCount(Query query, int resultCount) {
131     }
132
133     public void nextDataRows(Query query, List JavaDoc dataRows) {
134     }
135
136     public void nextDataRows(Query q, ResultIterator it) {
137         throw new UnsupportedOperationException JavaDoc(
138                 "'nextDataRows(Query,ResultIterator)' is unsupported (and unexpected) on commit.");
139     }
140
141     public boolean isIteratedResult() {
142         return false;
143     }
144 }
145
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