/**
* Flushes all value caches contained within entities controlled by this <code>EntityManager
* </code> instance. This does not actually remove the entities from the instance cache maintained
* within this class. Rather, it simply dumps all of the field values cached within the entities
* themselves (with the exception of the primary key value). This should be used in the case of a
* complex process outside AO control which may have changed values in the database. If it is at
* all possible to determine precisely which rows have been changed, the {@link
* #flush(RawEntity...)} method should be used instead.
*/
public void flushAll() {
List<Map.Entry<RawEntity<?>, EntityProxy<? extends RawEntity<?>, ?>>> toFlush =
new LinkedList<Map.Entry<RawEntity<?>, EntityProxy<? extends RawEntity<?>, ?>>>();
proxyLock.readLock().lock();
try {
for (Map.Entry<RawEntity<?>, EntityProxy<? extends RawEntity<?>, ?>> proxy :
proxies.entrySet()) {
toFlush.add(proxy);
}
} finally {
proxyLock.readLock().unlock();
}
for (Map.Entry<RawEntity<?>, EntityProxy<? extends RawEntity<?>, ?>> entry : toFlush) {
entry.getValue().flushCache(entry.getKey());
}
relationsCache.flush();
}
/**
* Flushes the value caches of the specified entities along with all of the relevant relations
* cache entries. This should be called after a process outside of AO control may have modified
* the values in the specified rows. This does not actually remove the entity instances themselves
* from the instance cache. Rather, it just flushes all of their internally cached values (with
* the exception of the primary key).
*/
public void flush(RawEntity<?>... entities) {
List<Class<? extends RawEntity<?>>> types =
new ArrayList<Class<? extends RawEntity<?>>>(entities.length);
Map<RawEntity<?>, EntityProxy<?, ?>> toFlush = new HashMap<RawEntity<?>, EntityProxy<?, ?>>();
proxyLock.readLock().lock();
try {
for (RawEntity<?> entity : entities) {
verify(entity);
types.add(entity.getEntityType());
toFlush.put(entity, proxies.get(entity));
}
} finally {
proxyLock.readLock().unlock();
}
for (Entry<RawEntity<?>, EntityProxy<?, ?>> entry : toFlush.entrySet()) {
entry.getValue().flushCache(entry.getKey());
}
relationsCache.remove(types.toArray(new Class[types.size()]));
}
/**
* Deletes the specified entities from the database. DELETE statements are called on the rows in
* the corresponding tables and the entities are removed from the instance cache. The entity
* instances themselves are not invalidated, but it doesn't even make sense to continue using the
* instance without a row with which it is paired.
*
* <p>This method does attempt to group the DELETE statements on a per-type basis. Thus, if you
* pass 5 instances of <code>EntityA</code> and two instances of <code>EntityB</code>, the
* following SQL prepared statements will be invoked:
*
* <pre>DELETE FROM entityA WHERE id IN (?,?,?,?,?);
* DELETE FROM entityB WHERE id IN (?,?);</pre>
*
* <p>Thus, this method scales very well for large numbers of entities grouped into types.
* However, the execution time increases linearly for each entity of unique type.
*
* @param entities A varargs array of entities to delete. Method returns immediately if length ==
* 0.
*/
@SuppressWarnings("unchecked")
public void delete(RawEntity<?>... entities) throws SQLException {
if (entities.length == 0) {
return;
}
Map<Class<? extends RawEntity<?>>, List<RawEntity<?>>> organizedEntities =
new HashMap<Class<? extends RawEntity<?>>, List<RawEntity<?>>>();
for (RawEntity<?> entity : entities) {
verify(entity);
Class<? extends RawEntity<?>> type = getProxyForEntity(entity).getType();
if (!organizedEntities.containsKey(type)) {
organizedEntities.put(type, new LinkedList<RawEntity<?>>());
}
organizedEntities.get(type).add(entity);
}
entityCacheLock.writeLock().lock();
try {
DatabaseProvider provider = getProvider();
Connection conn = provider.getConnection();
try {
for (Class<? extends RawEntity<?>> type : organizedEntities.keySet()) {
List<RawEntity<?>> entityList = organizedEntities.get(type);
StringBuilder sql = new StringBuilder("DELETE FROM ");
tableNameConverterLock.readLock().lock();
try {
sql.append(provider.processID(tableNameConverter.getName(type)));
} finally {
tableNameConverterLock.readLock().unlock();
}
sql.append(" WHERE ")
.append(provider.processID(Common.getPrimaryKeyField(type, getFieldNameConverter())))
.append(" IN (?");
for (int i = 1; i < entityList.size(); i++) {
sql.append(",?");
}
sql.append(')');
Logger.getLogger("net.java.ao").log(Level.INFO, sql.toString());
PreparedStatement stmt = conn.prepareStatement(sql.toString());
int index = 1;
for (RawEntity<?> entity : entityList) {
TypeManager.getInstance()
.getType((Class) entity.getEntityType())
.putToDatabase(this, stmt, index++, entity);
}
relationsCache.remove(type);
stmt.executeUpdate();
stmt.close();
}
} finally {
conn.close();
}
for (RawEntity<?> entity : entities) {
entityCache.remove(new CacheKey(Common.getPrimaryKeyValue(entity), entity.getEntityType()));
}
proxyLock.writeLock().lock();
try {
for (RawEntity<?> entity : entities) {
proxies.remove(entity);
}
} finally {
proxyLock.writeLock().unlock();
}
} finally {
entityCacheLock.writeLock().unlock();
}
}
/**
* Creates a new entity of the specified type with the optionally specified initial parameters.
* This method actually inserts a row into the table represented by the entity type and returns
* the entity instance which corresponds to that row.
*
* <p>The {@link DBParam} object parameters are designed to allow the creation of entities which
* have non-null fields which have no defalut or auto-generated value. Insertion of a row without
* such field values would of course fail, thus the need for db params. The db params can also be
* used to set the values for any field in the row, leading to more compact code under certain
* circumstances.
*
* <p>Unless within a transaction, this method will commit to the database immediately and exactly
* once per call. Thus, care should be taken in the creation of large numbers of entities. There
* doesn't seem to be a more efficient way to create large numbers of entities, however one should
* still be aware of the performance implications.
*
* <p>This method delegates the action INSERT action to {@link
* DatabaseProvider#insertReturningKey(EntityManager, Connection, Class, String, boolean, String,
* DBParam...)}. This is necessary because not all databases support the JDBC <code>
* RETURN_GENERATED_KEYS</code> constant (e.g. PostgreSQL and HSQLDB). Thus, the database provider
* itself is responsible for handling INSERTion and retrieval of the correct primary key value.
*
* @param type The type of the entity to INSERT.
* @param params An optional varargs array of initial values for the fields in the row. These
* values will be passed to the database within the INSERT statement.
* @return The new entity instance corresponding to the INSERTed row.
* @see net.java.ao.DBParam
* @see net.java.ao.DatabaseProvider#insertReturningKey(EntityManager, Connection, Class, String,
* boolean, String, DBParam...)
*/
public <T extends RawEntity<K>, K> T create(Class<T> type, DBParam... params)
throws SQLException {
T back = null;
String table = null;
tableNameConverterLock.readLock().lock();
try {
table = tableNameConverter.getName(type);
} finally {
tableNameConverterLock.readLock().unlock();
}
Set<DBParam> listParams = new HashSet<DBParam>();
listParams.addAll(Arrays.asList(params));
fieldNameConverterLock.readLock().lock();
try {
for (Method method : MethodFinder.getInstance().findAnnotation(Generator.class, type)) {
Generator genAnno = method.getAnnotation(Generator.class);
String field = fieldNameConverter.getName(method);
ValueGenerator<?> generator;
valGenCacheLock.writeLock().lock();
try {
if (valGenCache.containsKey(genAnno.value())) {
generator = valGenCache.get(genAnno.value());
} else {
generator = genAnno.value().newInstance();
valGenCache.put(genAnno.value(), generator);
}
} catch (InstantiationException e) {
continue;
} catch (IllegalAccessException e) {
continue;
} finally {
valGenCacheLock.writeLock().unlock();
}
listParams.add(new DBParam(field, generator.generateValue(this)));
}
// <ian>
Version version = type.getAnnotation(Version.class);
if (version != null) {
// Initialize version upon creation.
String field = version.value();
int initial = version.initial();
listParams.add(new DBParam(field, initial));
}
// </ian>
} finally {
fieldNameConverterLock.readLock().unlock();
}
Connection conn = getProvider().getConnection();
try {
Method pkMethod = Common.getPrimaryKeyMethod(type);
back =
peer(
type,
provider.insertReturningKey(
this,
conn,
Common.getPrimaryKeyClassType(type),
Common.getPrimaryKeyField(type, getFieldNameConverter()),
pkMethod.getAnnotation(AutoIncrement.class) != null,
table,
listParams.toArray(new DBParam[listParams.size()])));
} finally {
conn.close();
}
relationsCache.remove(type);
back.init();
return back;
}
