/src/com/google/appengine/datanucleus/mapping/DatastoreProperty.java

  1/**********************************************************************
  2Copyright (c) 2009 Google Inc.
  3
  4Licensed under the Apache License, Version 2.0 (the "License");
  5you may not use this file except in compliance with the License.
  6You may obtain a copy of the License at
  7
  8http://www.apache.org/licenses/LICENSE-2.0
  9
 10Unless required by applicable law or agreed to in writing, software
 11distributed under the License is distributed on an "AS IS" BASIS,
 12WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 13See the License for the specific language governing permissions and
 14limitations under the License.
 15**********************************************************************/
 16package com.google.appengine.datanucleus.mapping;
 17
 18import org.datanucleus.metadata.AbstractMemberMetaData;
 19import org.datanucleus.metadata.ColumnMetaData;
 20import org.datanucleus.store.mapped.DatastoreField;
 21import org.datanucleus.store.mapped.DatastoreIdentifier;
 22import org.datanucleus.store.mapped.MappedStoreManager;
 23import org.datanucleus.store.mapped.mapping.DatastoreMapping;
 24import org.datanucleus.store.mapped.mapping.JavaTypeMapping;
 25
 26/**
 27 * Describes a property in the datastore.
 28 *
 29 * Mostly copied from Column.
 30 *
 31 * @author Max Ross <maxr@google.com>
 32 */
 33class DatastoreProperty implements DatastoreField {
 34
 35  /** Identifier for the column in the datastore. */
 36  private DatastoreIdentifier identifier;
 37
 38  /** ColumnMetaData for this column. */
 39  private ColumnMetaData columnMetaData;
 40
 41  /** Table containing this column in the datastore. */
 42  private final DatastoreTable table;
 43
 44  /** Datastore mapping for this column. */
 45  private DatastoreMapping datastoreMapping = null;
 46
 47  /** Java type that this column is storing. (can we just get this from the mapping above ?) */
 48  private final String storedJavaType;
 49
 50  /** Manager for the store into which we are persisting. */
 51  private final MappedStoreManager storeMgr;
 52
 53  /** Flag indicating whether or not this is a pk */
 54  private boolean isPrimaryKey;
 55
 56  /** Flag indicating whether the user wants the property to be nullable or not */
 57  private boolean isNullable;
 58  
 59  /**
 60   * {@link #getMemberMetaData()} typically derives this from the parent of
 61   * {@link #columnMetaData} but if this member is set it just returns
 62   * it directly.
 63   */
 64  private AbstractMemberMetaData ammd;
 65
 66  public DatastoreProperty(DatastoreTable table, String javaType,
 67      DatastoreIdentifier identifier, ColumnMetaData colmd) {
 68    this.table = table;
 69    this.storedJavaType = javaType;
 70    this.storeMgr = table.getStoreManager();
 71
 72    setIdentifier(identifier);
 73    if (colmd == null) {
 74      // Create a default ColumnMetaData since none provided
 75      columnMetaData = new ColumnMetaData();
 76    } else {
 77      columnMetaData = colmd;
 78    }
 79
 80    // if not specified by the user the getAllowsNull is null
 81    isNullable = !Boolean.FALSE.equals(columnMetaData.getAllowsNull());
 82    
 83    // Uniqueness
 84    if (columnMetaData.getUnique()) {
 85      // MetaData requires it to be unique
 86      throw new UnsupportedOperationException("No support for uniqueness constraints");
 87    }
 88  }
 89
 90  public String getStoredJavaType() {
 91    return storedJavaType;
 92  }
 93
 94  public void setAsPrimaryKey() {
 95    isPrimaryKey = true;
 96  }
 97
 98  public boolean isPrimaryKey() {
 99    return isPrimaryKey;
100  }
101
102  public boolean isNullable() {
103    return isNullable;
104  }
105
106  public DatastoreMapping getDatastoreMapping() {
107    return datastoreMapping;
108  }
109
110  public void setDatastoreMapping(DatastoreMapping mapping) {
111    this.datastoreMapping = mapping;
112  }
113
114  public DatastoreTable getDatastoreContainerObject() {
115    return table;
116  }
117
118  public String applySelectFunction(String replacementValue) {
119    throw new UnsupportedOperationException("Select function not supported");
120  }
121
122  public void copyConfigurationTo(DatastoreField field) {
123    DatastoreProperty prop = (DatastoreProperty) field;
124    prop.isPrimaryKey = this.isPrimaryKey;
125  }
126
127  public DatastoreField setNullable() {
128    // all properties are nullable
129    return this;
130  }
131
132  public DatastoreField setDefaultable() {
133    throw new UnsupportedOperationException("Default values not supported");
134  }
135
136  public void setIdentifier(DatastoreIdentifier identifier) {
137    this.identifier = identifier;
138  }
139
140  public MappedStoreManager getStoreManager() {
141    return storeMgr;
142  }
143
144  public DatastoreIdentifier getIdentifier() {
145    return identifier;
146  }
147
148  public boolean isDefaultable() {
149    return false;
150  }
151
152  public DatastoreField setUnique() {
153    return this;
154  }
155
156  public boolean isUnique() {
157    return false;
158  }
159
160  public DatastoreField setIdentity(boolean b) {
161    isPrimaryKey = b;
162    return this;
163  }
164
165  public boolean isIdentity() {
166    return isPrimaryKey();
167  }
168
169  public void setDefaultValue(Object o) {
170    throw new UnsupportedOperationException("Default values not supported.");
171  }
172
173  public Object getDefaultValue() {
174    return null;
175  }
176
177  public void setColumnMetaData(ColumnMetaData columnMetaData) {
178    this.columnMetaData = columnMetaData;
179  }
180
181  public ColumnMetaData getColumnMetaData() {
182    return columnMetaData;
183  }
184
185  public JavaTypeMapping getJavaTypeMapping() {
186    return datastoreMapping.getJavaTypeMapping();
187  }
188
189  public AbstractMemberMetaData getMemberMetaData() {
190    if (ammd != null) {
191      return ammd;
192    }
193    if (columnMetaData != null && columnMetaData.getParent() instanceof AbstractMemberMetaData) {
194        return (AbstractMemberMetaData)columnMetaData.getParent();
195    }
196    return null;
197  }
198
199  void setMemberMetaData(AbstractMemberMetaData ammd) {
200    this.ammd = ammd;
201  }
202}