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1
16
17 package org.springframework.dao.support;
18
19 import java.util.Collection  ;
20
21 import org.springframework.dao.DataAccessException;
22 import org.springframework.dao.EmptyResultDataAccessException;
23 import org.springframework.dao.IncorrectResultSizeDataAccessException;
24 import org.springframework.dao.TypeMismatchDataAccessException;
25 import org.springframework.util.Assert;
26 import org.springframework.util.CollectionUtils;
27 import org.springframework.util.NumberUtils;
28
29
36 public abstract class DataAccessUtils {
37
38
47 public static Object singleResult(Collection results) throws IncorrectResultSizeDataAccessException {
48 int size = (results != null ? results.size() : 0);
49 if (size == 0) {
50 return null;
51 }
52 if (results.size() > 1) {
53 throw new IncorrectResultSizeDataAccessException(1, size);
54 }
55 return results.iterator().next();
56 }
57
58
68 public static Object requiredSingleResult(Collection results) throws IncorrectResultSizeDataAccessException {
69 int size = (results != null ? results.size() : 0);
70 if (size == 0) {
71 throw new EmptyResultDataAccessException(1);
72 }
73 if (results.size() > 1) {
74 throw new IncorrectResultSizeDataAccessException(1, size);
75 }
76 return results.iterator().next();
77 }
78
79
89 public static Object uniqueResult(Collection results) throws IncorrectResultSizeDataAccessException {
90 int size = (results != null ? results.size() : 0);
91 if (size == 0) {
92 return null;
93 }
94 if (!CollectionUtils.hasUniqueObject(results)) {
95 throw new IncorrectResultSizeDataAccessException(1, size);
96 }
97 return results.iterator().next();
98 }
99
100
111 public static Object requiredUniqueResult(Collection results) throws IncorrectResultSizeDataAccessException {
112 int size = (results != null ? results.size() : 0);
113 if (size == 0) {
114 throw new EmptyResultDataAccessException(1);
115 }
116 if (!CollectionUtils.hasUniqueObject(results)) {
117 throw new IncorrectResultSizeDataAccessException(1, size);
118 }
119 return results.iterator().next();
120 }
121
122
136 public static Object objectResult(Collection results, Class requiredType)
137 throws IncorrectResultSizeDataAccessException, TypeMismatchDataAccessException {
138
139 Object result = requiredUniqueResult(results);
140 if (requiredType != null && !requiredType.isInstance(result)) {
141 if (String .class.equals(requiredType)) {
142 result = result.toString();
143 }
144 else if (Number .class.isAssignableFrom(requiredType) && Number .class.isInstance(result)) {
145 try {
146 result = NumberUtils.convertNumberToTargetClass(((Number ) result), requiredType);
147 }
148 catch (IllegalArgumentException ex) {
149 throw new TypeMismatchDataAccessException(ex.getMessage());
150 }
151 }
152 else {
153 throw new TypeMismatchDataAccessException(
154 "Result object is of type [" + result.getClass().getName() +
155 "] and could not be converted to required type [" + requiredType.getName() + "]");
156 }
157 }
158 return result;
159 }
160
161
174 public static int intResult(Collection results)
175 throws IncorrectResultSizeDataAccessException, TypeMismatchDataAccessException {
176
177 return ((Number ) objectResult(results, Number .class)).intValue();
178 }
179
180
193 public static long longResult(Collection results)
194 throws IncorrectResultSizeDataAccessException, TypeMismatchDataAccessException {
195
196 return ((Number ) objectResult(results, Number .class)).longValue();
197 }
198
199
200
208 public static RuntimeException translateIfNecessary(
209 RuntimeException rawException, PersistenceExceptionTranslator pet) {
210
211 Assert.notNull(pet, "PersistenceExceptionTranslator must not be null");
212 DataAccessException dex = pet.translateExceptionIfPossible(rawException);
213 return (dex != null ? dex : rawException);
214 }
215
216 }
217 |
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