| Clover coverage report - Code Coverage for tapestry release 4.0.3 |
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| Source file | Conditionals | Statements | Methods | TOTAL | |||||||||||||||
| DefaultPrimaryKeyConverter.java | 86.4% | 98.1% | 100% | 95.7% |
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| 1 | // Copyright 2005 The Apache Software Foundation | |
| 2 | // | |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); | |
| 4 | // you may not use this file except in compliance with the License. | |
| 5 | // You may obtain a copy of the License at | |
| 6 | // | |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 | |
| 8 | // | |
| 9 | // Unless required by applicable law or agreed to in writing, software | |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, | |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| 12 | // See the License for the specific language governing permissions and | |
| 13 | // limitations under the License. | |
| 14 | ||
| 15 | package org.apache.tapestry.util; | |
| 16 | ||
| 17 | import java.util.ArrayList; | |
| 18 | import java.util.Collections; | |
| 19 | import java.util.HashMap; | |
| 20 | import java.util.HashSet; | |
| 21 | import java.util.List; | |
| 22 | import java.util.Map; | |
| 23 | import java.util.Set; | |
| 24 | ||
| 25 | import org.apache.hivemind.ApplicationRuntimeException; | |
| 26 | import org.apache.hivemind.util.Defense; | |
| 27 | import org.apache.tapestry.components.IPrimaryKeyConverter; | |
| 28 | ||
| 29 | /** | |
| 30 | * Companion to the {@link org.apache.tapestry.components.ForBean For component}, this class is an | |
| 31 | * implementation of {@link org.apache.tapestry.components.IPrimaryKeyConverter} that performs some | |
| 32 | * additional handling, such as tracking value sets.. | |
| 33 | * <p> | |
| 34 | * Value sets are sets of value objects maintained by the converter; the converter will provide a | |
| 35 | * synthetic read/write boolean property that indicates if the {@link #getLastValue() last value} is | |
| 36 | * or is not in the set. | |
| 37 | * <p> | |
| 38 | * A single built-in value set, {@link #isDeleted()} has a special purpose; it controls whether or | |
| 39 | * not values are returned from {@link #getValues()}. Subclasses may add additional synthetic | |
| 40 | * boolean properties and additional sets. | |
| 41 | * <p> | |
| 42 | * Why not just store a boolean property in the object itself? Well, deleted is a good example of a | |
| 43 | * property that is meaningful in the context of an operation, but isn't stored ... once an object | |
| 44 | * is deleted (from secondary storage, such as a database) there's no place to store such a flag. | |
| 45 | * The DefaultPrimaryKey converter is used in this context to store transient, operation data ... | |
| 46 | * such as which values are to be deleted. | |
| 47 | * <p> | |
| 48 | * This class can be thought of as a successor to {@link org.apache.tapestry.form.ListEditMap}. | |
| 49 | * | |
| 50 | * @author Howard M. Lewis Ship | |
| 51 | * @since 4.0 | |
| 52 | */ | |
| 53 | public class DefaultPrimaryKeyConverter implements IPrimaryKeyConverter | |
| 54 | { | |
| 55 | private final Map _map = new HashMap(); | |
| 56 | ||
| 57 | private final List _keys = new ArrayList(); | |
| 58 | ||
| 59 | // The values added to the Map, in the order they were added. | |
| 60 | private final List _values = new ArrayList(); | |
| 61 | ||
| 62 | // The last value accessed by getPrimaryKey() or getValue(). | |
| 63 | // Other methods may operate upon this value. | |
| 64 | ||
| 65 | private Object _lastValue; | |
| 66 | ||
| 67 | private Set _deletedValues; | |
| 68 | ||
| 69 | /** | |
| 70 | * Clears all properties of the converter, returning it to a pristine state. Subclasses should | |
| 71 | * invoke this implementation in addition to clearing any of their own state. | |
| 72 | */ | |
| 73 | 3 | public void clear() |
| 74 | { | |
| 75 | 3 | _map.clear(); |
| 76 | 3 | _keys.clear(); |
| 77 | 3 | _values.clear(); |
| 78 | 3 | _lastValue = null; |
| 79 | 3 | _deletedValues = null; |
| 80 | } | |
| 81 | ||
| 82 | 51 | public final void add(Object key, Object value) |
| 83 | { | |
| 84 | 51 | Defense.notNull(key, "key"); |
| 85 | 51 | Defense.notNull(value, "value"); |
| 86 | ||
| 87 | 51 | if (_map.containsKey(key)) |
| 88 | 3 | throw new ApplicationRuntimeException(UtilMessages.keyAlreadyExists(key)); |
| 89 | ||
| 90 | 48 | _map.put(key, value); |
| 91 | ||
| 92 | 48 | _keys.add(key); |
| 93 | 48 | _values.add(value); |
| 94 | ||
| 95 | 48 | _lastValue = value; |
| 96 | } | |
| 97 | ||
| 98 | /** | |
| 99 | * Returns a unmodifiable list of values stored into the converter, in the order in which they | |
| 100 | * were stored. | |
| 101 | * | |
| 102 | * @return an unmodifiable List | |
| 103 | * @see #add(Object, Object) | |
| 104 | */ | |
| 105 | 24 | public final List getAllValues() |
| 106 | { | |
| 107 | 24 | return Collections.unmodifiableList(_values); |
| 108 | } | |
| 109 | ||
| 110 | /** | |
| 111 | * Returns a list of all values stored into the converter, with deleted values removed. | |
| 112 | */ | |
| 113 | ||
| 114 | 21 | public final List getValues() |
| 115 | { | |
| 116 | 21 | if (isDeletedValuesEmpty()) |
| 117 | 12 | return getAllValues(); |
| 118 | ||
| 119 | 9 | List result = new ArrayList(_values); |
| 120 | ||
| 121 | 9 | result.removeAll(_deletedValues); |
| 122 | ||
| 123 | 9 | return result; |
| 124 | } | |
| 125 | ||
| 126 | /** | |
| 127 | * Returns true if the deleted values set is empty (or null).l | |
| 128 | */ | |
| 129 | 24 | private boolean isDeletedValuesEmpty() |
| 130 | { | |
| 131 | 24 | return _deletedValues == null || _deletedValues.isEmpty(); |
| 132 | } | |
| 133 | ||
| 134 | /** | |
| 135 | * Checks to see if the {@link #getLastValue() last value} is, or is not, in the set of deleted | |
| 136 | * values. | |
| 137 | */ | |
| 138 | 9 | public final boolean isDeleted() |
| 139 | { | |
| 140 | 9 | return checkValueSetForLastValue(_deletedValues); |
| 141 | } | |
| 142 | ||
| 143 | /** | |
| 144 | * Checks the set to see if it contains the {@link #getLastValue() last value}. | |
| 145 | * | |
| 146 | * @param valueSet | |
| 147 | * the set to check, which may be null | |
| 148 | * @return true if the last value is in the set (if non-null) | |
| 149 | */ | |
| 150 | 9 | protected final boolean checkValueSetForLastValue(Set valueSet) |
| 151 | { | |
| 152 | 9 | return valueSet != null && valueSet.contains(_lastValue); |
| 153 | } | |
| 154 | ||
| 155 | /** | |
| 156 | * Adds or removes the {@link #getLastValue() last value} from the | |
| 157 | * {@link #getDeletedValues() deleted values set}. | |
| 158 | * | |
| 159 | * @param deleted | |
| 160 | */ | |
| 161 | 15 | public final void setDeleted(boolean deleted) |
| 162 | { | |
| 163 | 15 | _deletedValues = updateValueSetForLastValue(_deletedValues, deleted); |
| 164 | } | |
| 165 | ||
| 166 | /** | |
| 167 | * Updates a value set to add or remove the {@link #getLastValue() last value} to the set. The | |
| 168 | * logic here will create and return a new Set instance if necessary (that is, if inSet is true | |
| 169 | * and set is null). The point is to defer the creation of the set until its actually needed. | |
| 170 | * | |
| 171 | * @param set | |
| 172 | * the set to update, which may be null | |
| 173 | * @param inSet | |
| 174 | * if true, the last value will be added to the set (creating the set as necessary); | |
| 175 | * if false, the last value will be removed | |
| 176 | * @return the set passed in, or a new Set instance | |
| 177 | */ | |
| 178 | 15 | protected final Set updateValueSetForLastValue(Set set, boolean inSet) |
| 179 | { | |
| 180 | 15 | if (inSet) |
| 181 | { | |
| 182 | 12 | if (set == null) |
| 183 | 12 | set = new HashSet(); |
| 184 | ||
| 185 | 12 | set.add(_lastValue); |
| 186 | ||
| 187 | 12 | return set; |
| 188 | } | |
| 189 | ||
| 190 | 3 | if (set != null) |
| 191 | 3 | set.remove(_lastValue); |
| 192 | ||
| 193 | 3 | return set; |
| 194 | } | |
| 195 | ||
| 196 | /** | |
| 197 | * Returns the last active value; this is the value passed to {@link #getPrimaryKey(Object)} or | |
| 198 | * the value for the key passed to {@link #getValue(Object)}. | |
| 199 | * <p> | |
| 200 | * Maintaining <em>value sets</em> involves adding or removing the active value from a set. | |
| 201 | * | |
| 202 | * @return the last active object | |
| 203 | */ | |
| 204 | 27 | public final Object getLastValue() |
| 205 | { | |
| 206 | 27 | return _lastValue; |
| 207 | } | |
| 208 | ||
| 209 | /** | |
| 210 | * Returns an unmodifiable set of all values marked as deleted. | |
| 211 | */ | |
| 212 | ||
| 213 | 18 | public final Set getDeletedValues() |
| 214 | { | |
| 215 | 18 | return createUnmodifiableSet(_deletedValues); |
| 216 | } | |
| 217 | ||
| 218 | /** | |
| 219 | * Converts a value set into a returnable value; null is converted to the empty set, and | |
| 220 | * non-null is wrapped as unmodifiable. | |
| 221 | * | |
| 222 | * @param valueSet | |
| 223 | * the set to convert and return | |
| 224 | * @return a non-null, non-modifiable Set | |
| 225 | */ | |
| 226 | 18 | protected final Set createUnmodifiableSet(Set valueSet) |
| 227 | { | |
| 228 | 18 | return valueSet == null ? Collections.EMPTY_SET : Collections.unmodifiableSet(valueSet); |
| 229 | } | |
| 230 | ||
| 231 | /** | |
| 232 | * Iterates over the keys and values, removing any values (and corresponding keys) that that are | |
| 233 | * in the deleted set. After invoking this, {@link #getAllValues()} will be the same as | |
| 234 | * {@link #getValues()}. | |
| 235 | */ | |
| 236 | 3 | public final void removeDeletedValues() |
| 237 | { | |
| 238 | 3 | _lastValue = null; |
| 239 | ||
| 240 | 3 | if (isDeletedValuesEmpty()) |
| 241 | 0 | return; |
| 242 | ||
| 243 | 3 | int count = _keys.size(); |
| 244 | ||
| 245 | 3 | for (int i = count - 1; i >= 0; i--) |
| 246 | { | |
| 247 | 6 | if (_deletedValues.contains(_values.get(i))) |
| 248 | { | |
| 249 | 3 | _values.remove(i); |
| 250 | 3 | Object key = _keys.remove(i); |
| 251 | ||
| 252 | 3 | _map.remove(key); |
| 253 | } | |
| 254 | } | |
| 255 | } | |
| 256 | ||
| 257 | /** | |
| 258 | * Gets the primary key of an object previously stored in this converter. | |
| 259 | * | |
| 260 | * @param value | |
| 261 | * an object previously stored in the converter | |
| 262 | * @return the corresponding key used to store the object | |
| 263 | * @throws ApplicationRuntimeException | |
| 264 | * if the value was not previously stored | |
| 265 | * @see #add(Object, Object) | |
| 266 | */ | |
| 267 | 12 | public final Object getPrimaryKey(Object value) |
| 268 | { | |
| 269 | 12 | int index = _values.indexOf(value); |
| 270 | ||
| 271 | 12 | if (index < 0) |
| 272 | 3 | throw new ApplicationRuntimeException(UtilMessages.valueNotFound(value), value, null, |
| 273 | null); | |
| 274 | ||
| 275 | 9 | _lastValue = value; |
| 276 | ||
| 277 | 9 | return _keys.get(index); |
| 278 | } | |
| 279 | ||
| 280 | /** | |
| 281 | * Given a primary key, locates the corresponding object. May invoke | |
| 282 | * {@link #provideMissingValue(Object)} if no such key has been stored into the converter. | |
| 283 | * | |
| 284 | * @return the object if the key is found, or null otherwise. | |
| 285 | * @see #add(Object, Object) | |
| 286 | */ | |
| 287 | 21 | public final Object getValue(Object primaryKey) |
| 288 | { | |
| 289 | 21 | Object result = _map.get(primaryKey); |
| 290 | ||
| 291 | 21 | if (result == null) |
| 292 | 9 | result = provideMissingValue(primaryKey); |
| 293 | ||
| 294 | 18 | _lastValue = result; |
| 295 | ||
| 296 | 18 | return result; |
| 297 | } | |
| 298 | ||
| 299 | /** | |
| 300 | * Invoked by {@link #getValue(Object)} when the key is not found in the converter's map. | |
| 301 | * Subclasses may override this method to either obtain the corresponding object from secondary | |
| 302 | * storage, to throw an exception, or to provide a new object instance. This implementation | |
| 303 | * returns null. | |
| 304 | * | |
| 305 | * @param key | |
| 306 | * the key for which an object was requested | |
| 307 | * @return the object for the key, or null if no object may can be provided | |
| 308 | */ | |
| 309 | 3 | protected Object provideMissingValue(Object key) |
| 310 | { | |
| 311 | 3 | return null; |
| 312 | } | |
| 313 | ||
| 314 | } |
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