#668 - ENH: Add ability to register a custom IdGenerator

src/main/java/com/avaje/ebean/config/IdGenerator.java

@@ -0,0 +1,22 @@
+package com.avaje.ebean.config;
+
+/**
+ * A customer Id generator that can be registered with Ebean and
+ * assigned to @Id properties using the name attribute of @GeneratedValue.
+ */
+public interface IdGenerator {
+
+  /**
+   * Return the next Id value.
+   */
+  Object nextValue();
+
+  /**
+   * Return the name of the IdGenerator.
+   * <p>
+   * The name is used to assign the IdGenerator to a property using
+   * <code>@GeneratedValue(name="myGeneratorName")</code>
+   * </p>
+   */
+  String getName();
+}

src/main/java/com/avaje/ebean/config/ServerConfig.java

@@ -3,7 +3,6 @@ package com.avaje.ebean.config;
 import com.avaje.ebean.EbeanServerFactory;
 import com.avaje.ebean.PersistenceContextScope;
 import com.avaje.ebean.annotation.Encrypted;
-import com.avaje.ebean.cache.ServerCacheFactory;
 import com.avaje.ebean.cache.ServerCacheManager;
 import com.avaje.ebean.cache.ServerCachePlugin;
 import com.avaje.ebean.config.dbplatform.DatabasePlatform;
@@ -46,37 +45,36 @@ import java.util.ServiceLoader;
  * includes searching the class path and automatically registering any entity
  * classes and listeners etc.
  * </p>
- * 
+ *
  * <pre>{@code
  * ServerConfig c = new ServerConfig();
  * c.setName("ordh2");
- * 
+ *
  * // read the ebean.properties and load
  * // those settings into this serverConfig object
  * c.loadFromProperties();
- * 
+ *
  * // generate DDL and run it
  * c.setDdlGenerate(true);
  * c.setDdlRun(true);
- * 
+ *
  * // add any classes found in the app.data package
  * c.addPackage("app.data");
- * 
+ *
  * // add the names of Jars that contain entities
  * c.addJar("myJarContainingEntities.jar");
  * c.addJar("someOtherJarContainingEntities.jar");
- * 
+ *
  * // register as the 'Default' server
  * c.setDefaultServer(true);
- * 
+ *
  * EbeanServer server = EbeanServerFactory.create(c);
- * 
+ *
  * }</pre>
- * 
- * @see EbeanServerFactory
- * 
+ *
  * @author emcgreal
  * @author rbygrave
+ * @see EbeanServerFactory
  */
 public class ServerConfig {
 
@@ -89,7 +87,7 @@ public class ServerConfig {
    * Typically configuration type objects that are passed by this ServerConfig
    * to plugins. For example - IgniteConfiguration passed to Ignite plugin.
    */
-  private Map<String,Object> serviceObject = new HashMap<String, Object>();
+  private Map<String, Object> serviceObject = new HashMap<String, Object>();
 
   private ContainerConfig containerConfig;
 
@@ -152,7 +150,7 @@ public class ServerConfig {
    */
   private CurrentUserProvider currentUserProvider;
 
-  /** 
+  /**
    * Config controlling the AutoTune behaviour.
    */
   private AutoTuneConfig autoTuneConfig = new AutoTuneConfig();
@@ -168,13 +166,13 @@ public class ServerConfig {
    */
   private JsonConfig.Include jsonInclude = JsonConfig.Include.ALL;
 
-  /** 
-   * The database platform name. Used to imply a DatabasePlatform to use.  
+  /**
+   * The database platform name. Used to imply a DatabasePlatform to use.
    */
   private String databasePlatformName;
 
-  /** 
-   * The database platform. 
+  /**
+   * The database platform.
    */
   private DatabasePlatform databasePlatform;
 
@@ -213,12 +211,12 @@ public class ServerConfig {
 
   private int persistBatchSize = 20;
 
-  /** 
-   * The default batch size for lazy loading 
+  /**
+   * The default batch size for lazy loading
    */
   private int lazyLoadBatchSize = 10;
 
-  /** 
+  /**
    * The default batch size for 'query joins'.
    */
   private int queryBatchSize = 100;
@@ -248,12 +246,12 @@ public class ServerConfig {
   private ExternalTransactionManager externalTransactionManager;
 
   /**
-   * The data source (if programmatically provided). 
+   * The data source (if programmatically provided).
    */
   private DataSource dataSource;
 
-  /** 
-   * The data source config. 
+  /**
+   * The data source config.
    */
   private DataSourceConfig dataSourceConfig = new DataSourceConfig();
 
@@ -279,23 +277,23 @@ public class ServerConfig {
    */
   private boolean explicitTransactionBeginMode;
 
-  /** 
-   * The data source JNDI name if using a JNDI DataSource. 
+  /**
+   * The data source JNDI name if using a JNDI DataSource.
    */
   private String dataSourceJndiName;
 
-  /** 
+  /**
    * The database boolean true value (typically either 1, T, or Y).
    */
   private String databaseBooleanTrue;
 
-  /** 
-   * The database boolean false value (typically either 0, F or N). 
+  /**
+   * The database boolean false value (typically either 0, F or N).
    */
   private String databaseBooleanFalse;
 
-  /** 
-   * The naming convention. 
+  /**
+   * The naming convention.
    */
   private NamingConvention namingConvention = new UnderscoreNamingConvention();
 
@@ -304,7 +302,7 @@ public class ServerConfig {
    */
   private DbConstraintNaming constraintNaming = new DbConstraintNaming();
 
-  /** 
+  /**
    * Behaviour of update to include on the change properties.
    */
   private boolean updateChangesOnly = true;
@@ -318,13 +316,14 @@ public class ServerConfig {
    * Default behaviour for updates when cascade save on a O2M or M2M to delete any missing children.
    */
   private boolean updatesDeleteMissingChildren = true;
-  
+
   /**
    * Setting to indicate if UUID should be stored as binary(16) or varchar(40) or native DB type (for H2 and Postgres).
    */
   private DbUuid dbUuid = DbUuid.AUTO;
 
 
+  private List<IdGenerator> idGenerators = new ArrayList<IdGenerator>();
   private List<BeanFindController> findControllers = new ArrayList<BeanFindController>();
   private List<BeanPersistController> persistControllers = new ArrayList<BeanPersistController>();
   private List<BeanPostLoad> postLoaders = new ArrayList<BeanPostLoad>();
@@ -395,13 +394,13 @@ public class ServerConfig {
   private int cacheWarmingDelay = 30;
   private int cacheMaxSize = 10000;
   private int cacheMaxIdleTime = 600;
-  private int cacheMaxTimeToLive = 60*60*6;
+  private int cacheMaxTimeToLive = 60 * 60 * 6;
 
   // defaults for the L2 query caching
 
   private int queryCacheMaxSize = 1000;
   private int queryCacheMaxIdleTime = 600;
-  private int queryCacheMaxTimeToLive = 60*60*6;
+  private int queryCacheMaxTimeToLive = 60 * 60 * 6;
   private Object objectMapper;
 
   /**
@@ -444,7 +443,7 @@ public class ServerConfig {
   public Object getServiceObject(String key) {
     return serviceObject.get(key);
   }
-  
+
   /**
    * Return the Jackson JsonFactory to use.
    * <p>
@@ -671,6 +670,7 @@ public class ServerConfig {
    * <p>
    * You can also set the batch size on the transaction.
    * </p>
+   *
    * @see com.avaje.ebean.Transaction#setBatchSize(int)
    */
   public void setPersistBatchSize(int persistBatchSize) {
@@ -679,7 +679,7 @@ public class ServerConfig {
 
   /**
    * Gets the query batch size. This defaults to 100.
-   * 
+   *
    * @return the query batch size
    */
   public int getQueryBatchSize() {
@@ -688,9 +688,8 @@ public class ServerConfig {
 
   /**
    * Sets the query batch size. This defaults to 100.
-   * 
-   * @param queryBatchSize
-   *          the new query batch size
+   *
+   * @param queryBatchSize the new query batch size
    */
   public void setQueryBatchSize(int queryBatchSize) {
     this.queryBatchSize = queryBatchSize;
@@ -736,8 +735,8 @@ public class ServerConfig {
   /**
    * Return the ChangeLogPrepare.
    * <p>
-   *   This is used to set user context information to the ChangeSet in the
-   *   foreground thread prior to the logging occurring in a background thread.
+   * This is used to set user context information to the ChangeSet in the
+   * foreground thread prior to the logging occurring in a background thread.
    * </p>
    */
   public ChangeLogPrepare getChangeLogPrepare() {
@@ -747,8 +746,8 @@ public class ServerConfig {
   /**
    * Set the ChangeLogPrepare.
    * <p>
-   *   This is used to set user context information to the ChangeSet in the
-   *   foreground thread prior to the logging occurring in a background thread.
+   * This is used to set user context information to the ChangeSet in the
+   * foreground thread prior to the logging occurring in a background thread.
    * </p>
    */
   public void setChangeLogPrepare(ChangeLogPrepare changeLogPrepare) {
@@ -1309,7 +1308,7 @@ public class ServerConfig {
   public void setDataSourceJndiName(String dataSourceJndiName) {
     this.dataSourceJndiName = dataSourceJndiName;
   }
-  
+
   /**
    * Return true if autoCommit mode is on. This indicates to Ebean to use autoCommit friendly Transactions and TransactionManager.
    */
@@ -1488,12 +1487,11 @@ public class ServerConfig {
    * <p>
    * You can also set this in ebean.proprerties:
    * </p>
-   * 
-   * <pre class="code">
+   *
+   * <pre>{@code
    * # set via ebean.properties
-   * 
    * ebean.encryptKeyManager=com.avaje.tests.basic.encrypt.BasicEncyptKeyManager
-   * </pre>
+   * }</pre>
    */
   public void setEncryptKeyManager(EncryptKeyManager encryptKeyManager) {
     this.encryptKeyManager = encryptKeyManager;
@@ -1616,7 +1614,7 @@ public class ServerConfig {
 
   /**
    * Set to true to generate the "create all" DDL on startup.
-   *
+   * <p>
    * Typically we want this on when we are running tests locally (and often using H2)
    * and we want to create the full DB schema from scratch to run tests.
    */
@@ -1626,7 +1624,7 @@ public class ServerConfig {
 
   /**
    * Set to true to run the generated "create all DDL" on startup.
-   *
+   * <p>
    * Typically we want this on when we are running tests locally (and often using H2)
    * and we want to create the full DB schema from scratch to run tests.
    */
@@ -1636,7 +1634,7 @@ public class ServerConfig {
 
   /**
    * Return true if the "drop all ddl" should be skipped.
-   *
+   * <p>
    * Typically we want to do this when using H2 (in memory) as our test database and the drop statements
    * are not required so skipping the drop table statements etc makes it faster with less noise in the logs.
    */
@@ -1646,7 +1644,7 @@ public class ServerConfig {
 
   /**
    * Set to true if the "drop all ddl" should be skipped.
-   *
+   * <p>
    * Typically we want to do this when using H2 (in memory) as our test database and the drop statements
    * are not required so skipping the drop table statements etc makes it faster with less noise in the logs.
    */
@@ -1657,8 +1655,8 @@ public class ServerConfig {
   /**
    * Return SQL script to execute after the "create all" DDL has been run.
    * <p>
-   *   Typically this is a sql script that inserts test seed data when running tests.
-   *   Place a sql script in src/test/resources that inserts test seed data.
+   * Typically this is a sql script that inserts test seed data when running tests.
+   * Place a sql script in src/test/resources that inserts test seed data.
    * </p>
    */
   public String getDdlSeedSql() {
@@ -1668,8 +1666,8 @@ public class ServerConfig {
   /**
    * Set a SQL script to execute after the "create all" DDL has been run.
    * <p>
-   *   Typically this is a sql script that inserts test seed data when running tests.
-   *   Place a sql script in src/test/resources that inserts test seed data.
+   * Typically this is a sql script that inserts test seed data when running tests.
+   * Place a sql script in src/test/resources that inserts test seed data.
    * </p>
    */
   public void setDdlSeedSql(String ddlSeedSql) {
@@ -1748,10 +1746,9 @@ public class ServerConfig {
    * <p>
    * Alternatively the classes can be added via {@link #setClasses(List)}.
    * </p>
-   * 
-   * @param cls
-   *          the entity type (or other type) that should be registered by this
-   *          server.
+   *
+   * @param cls the entity type (or other type) that should be registered by this
+   *            server.
    */
   public void addClass(Class<?> cls) {
     if (classes == null) {
@@ -1802,13 +1799,13 @@ public class ServerConfig {
    * If you are using ebean.properties you can specify jars to search by setting
    * a ebean.search.jars property.
    * </p>
-   * 
-   * <pre class="code">
-   * # EBean will search through classes for entities, but will not search jar files 
-   * # unless you tell it to do so, for performance reasons.  Set this value to a 
+   *
+   * <pre>{@code
+   * # EBean will search through classes for entities, but will not search jar files
+   * # unless you tell it to do so, for performance reasons.  Set this value to a
    * # comma-delimited list of jar files you want ebean to search.
    * ebean.search.jars=example.jar
-   * </pre>
+   * }</pre>
    */
   public void addJar(String jarName) {
     if (searchJars == null) {
@@ -1846,7 +1843,7 @@ public class ServerConfig {
 
   /**
    * Set the class name of a classPathReader implementation.
-   *
+   * <p>
    * Refer to server.util.ClassPathReader, this should really by a plugin but doing this for now
    * to be relatively compatible with current implementation.
    */
@@ -1901,7 +1898,7 @@ public class ServerConfig {
   /**
    * Set to false if by default updates in JDBC batch should not include all properties.
    * <p>
-   *   This mode can be explicitly set per transaction.
+   * This mode can be explicitly set per transaction.
    * </p>
    *
    * @see com.avaje.ebean.Transaction#setUpdateAllLoadedProperties(boolean)
@@ -1944,6 +1941,7 @@ public class ServerConfig {
    * <p>
    * This information can be later retrieved via {@link MetaInfoManager}.
    * </p>
+   *
    * @see MetaInfoManager
    */
   public void setCollectQueryStatsByNode(boolean collectQueryStatsByNode) {
@@ -1964,6 +1962,7 @@ public class ServerConfig {
    * <p>
    * This information can be later retrieved via {@link MetaInfoManager}.
    * </p>
+   *
    * @see MetaInfoManager
    */
   public void setCollectQueryOrigins(boolean collectQueryOrigins) {
@@ -2013,6 +2012,27 @@ public class ServerConfig {
     this.queryAdapters = queryAdapters;
   }
 
+  /**
+   * Return the custom IdGenerator instances.
+   */
+  public List<IdGenerator> getIdGenerators() {
+    return idGenerators;
+  }
+
+  /**
+   * Set the custom IdGenerator instances.
+   */
+  public void setIdGenerators(List<IdGenerator> idGenerators) {
+    this.idGenerators = idGenerators;
+  }
+
+  /**
+   * Register a customer IdGenerator instance.
+   */
+  public void add(IdGenerator idGenerator) {
+    idGenerators.add(idGenerator);
+  }
+
   /**
    * Register a BeanPersistController instance.
    * <p>
@@ -2277,7 +2297,7 @@ public class ServerConfig {
    * @param instance   existing instance
    */
   @SuppressWarnings("unchecked")
-  protected  <T> T createInstance(PropertiesWrapper properties, Class<T> pluginType, String key, T instance) {
+  protected <T> T createInstance(PropertiesWrapper properties, Class<T> pluginType, String key, T instance) {
 
     if (instance != null) {
       return instance;
@@ -2288,8 +2308,9 @@ public class ServerConfig {
 
   /**
    * Return the instance to use (can be null) for the given plugin.
+   *
    * @param pluginType the type of plugin
-   * @param classname the implementation class as per properties
+   * @param classname  the implementation class as per properties
    */
   protected <T> T createInstance(Class<T> pluginType, String classname) {
     return classname == null ? null : (T) classLoadConfig.newInstance(classname);
@@ -2362,7 +2383,7 @@ public class ServerConfig {
     serverCacheManager = createInstance(p, ServerCacheManager.class, "serverCacheManager", serverCacheManager);
     cacheWarmingDelay = p.getInt("cacheWarmingDelay", cacheWarmingDelay);
     classPathReaderClassName = p.get("classpathreader");
-    
+
     String jarsProp = p.get("search.jars", p.get("jars", null));
     if (jarsProp != null) {
       searchJars = getSearchJarsPackages(jarsProp);
@@ -2378,7 +2399,7 @@ public class ServerConfig {
 
     updateAllPropertiesInBatch = p.getBoolean("updateAllPropertiesInBatch", updateAllPropertiesInBatch);
     updateChangesOnly = p.getBoolean("updateChangesOnly", updateChangesOnly);
-    
+
     boolean defaultDeleteMissingChildren = p.getBoolean("defaultDeleteMissingChildren", updatesDeleteMissingChildren);
     updatesDeleteMissingChildren = p.getBoolean("updatesDeleteMissingChildren", defaultDeleteMissingChildren);
 
@@ -2442,10 +2463,8 @@ public class ServerConfig {
 
   /**
    * Build the list of classes from the comma delimited string.
-   * 
-   * @param properties
-   *          the properties
-   * 
+   *
+   * @param properties the properties
    * @return the classes
    */
   private List<Class<?>> getClasses(PropertiesWrapper properties) {
@@ -2528,9 +2547,9 @@ public class ServerConfig {
   /**
    * Set to true if you want eq("someProperty", null) to generate "1=1" rather than "is null" sql expression.
    * <p>
-   *   Setting this to true has the effect that eq(propertyName, value), ieq(propertyName, value) and
-   *   ne(propertyName, value) have no effect when the value is null. The expression factory adds a NoopExpression
-   *   which will add "1=1" into the SQL rather than "is null".
+   * Setting this to true has the effect that eq(propertyName, value), ieq(propertyName, value) and
+   * ne(propertyName, value) have no effect when the value is null. The expression factory adds a NoopExpression
+   * which will add "1=1" into the SQL rather than "is null".
    * </p>
    */
   public void setExpressionEqualsWithNullAsNoop(boolean expressionEqualsWithNullAsNoop) {

src/main/java/com/avaje/ebeaninternal/server/core/BootupClasses.java

@@ -1,6 +1,7 @@
 package com.avaje.ebeaninternal.server.core;
 
 import com.avaje.ebean.config.CompoundType;
+import com.avaje.ebean.config.IdGenerator;
 import com.avaje.ebean.config.ScalarTypeConverter;
 import com.avaje.ebean.config.ServerConfig;
 import com.avaje.ebean.event.BeanFindController;
@@ -48,6 +49,8 @@ public class BootupClasses implements ClassPathSearchMatcher, ClassFilter {
 
   private final List<Class<?>> compoundTypeList = new ArrayList<Class<?>>();
 
+  private final List<Class<?>> idGeneratorList = new ArrayList<Class<?>>();
+
   private final List<Class<?>> beanControllerList = new ArrayList<Class<?>>();
 
   private final List<Class<?>> beanPostLoadList = new ArrayList<Class<?>>();
@@ -62,6 +65,7 @@ public class BootupClasses implements ClassPathSearchMatcher, ClassFilter {
   private final List<Class<?>> serverConfigStartupList = new ArrayList<Class<?>>();
   private final List<ServerConfigStartup> serverConfigStartupInstances = new ArrayList<ServerConfigStartup>();
 
+  private final List<IdGenerator> idGeneratorInstances = new ArrayList<IdGenerator>();
   private final List<BeanFindController> findControllerInstances = new ArrayList<BeanFindController>();
   private final List<BeanPersistController> persistControllerInstances = new ArrayList<BeanPersistController>();
   private final List<BeanPostLoad> beanPostLoadInstances = new ArrayList<BeanPostLoad>();
@@ -116,6 +120,19 @@ public class BootupClasses implements ClassPathSearchMatcher, ClassFilter {
     }
   }
 
+  /**
+   * Add IdGenerator instances (registered explicitly with the ServerConfig).
+   */
+  public void addIdGenerators(List<IdGenerator> idGenerators) {
+    if (idGenerators != null) {
+      for (IdGenerator c : idGenerators) {
+        this.idGeneratorInstances.add(c);
+        // don't automatically instantiate
+        this.idGeneratorList.remove(c.getClass());
+      }
+    }
+  }
+
   public void addQueryAdapters(List<BeanQueryAdapter> queryAdapterInstances) {
     if (queryAdapterInstances != null) {
       for (BeanQueryAdapter a : queryAdapterInstances) {
@@ -328,6 +345,13 @@ public class BootupClasses implements ClassPathSearchMatcher, ClassFilter {
     return beanPostLoadInstances;
   }
 
+  public List<IdGenerator> getIdGenerators() {
+    for (Class<?> cls : idGeneratorList) {
+      createAdd(cls, idGeneratorInstances);
+    }
+    return idGeneratorInstances;
+  }
+
   public List<TransactionEventListener> getTransactionEventListeners() {
     // add class registered TransactionEventListener to the already created instances
     for (Class<?> cls : transactionEventListenerList) {
@@ -402,6 +426,11 @@ public class BootupClasses implements ClassPathSearchMatcher, ClassFilter {
     }
     boolean interesting = false;
 
+    if (IdGenerator.class.isAssignableFrom(cls)) {
+      idGeneratorList.add(cls);
+      interesting = true;
+    }
+
     if (BeanPersistController.class.isAssignableFrom(cls)) {
       beanControllerList.add(cls);
       interesting = true;

src/main/java/com/avaje/ebeaninternal/server/core/DefaultContainer.java

@@ -194,6 +194,7 @@ public class DefaultContainer implements SpiContainer {
   private BootupClasses getBootupClasses(ServerConfig serverConfig) {
 
     BootupClasses bootupClasses = getBootupClasses1(serverConfig);
+    bootupClasses.addIdGenerators(serverConfig.getIdGenerators());
     bootupClasses.addPersistControllers(serverConfig.getPersistControllers());
     bootupClasses.addPostLoaders(serverConfig.getPostLoaders());
     bootupClasses.addFindControllers(serverConfig.getFindControllers());

src/main/java/com/avaje/ebeaninternal/server/core/InternalConfiguration.java

@@ -337,7 +337,7 @@ public class InternalConfiguration {
   }
 
   public GeneratedPropertyFactory getGeneratedPropertyFactory() {
-    return new GeneratedPropertyFactory(serverConfig);
+    return new GeneratedPropertyFactory(serverConfig, bootupClasses.getIdGenerators());
   }
 
   /**

src/main/java/com/avaje/ebeaninternal/server/deploy/BeanDescriptorManager.java

@@ -153,8 +153,6 @@ public class BeanDescriptorManager implements BeanDescriptorMap {
 
   private final DatabasePlatform databasePlatform;
 
-  private final UuidIdGenerator uuidIdGenerator = new UuidIdGenerator();
-
   private final ServerCacheManager cacheManager;
 
   private final BackgroundExecutor backgroundExecutor;
@@ -1177,6 +1175,10 @@ public class BeanDescriptorManager implements BeanDescriptorMap {
    */
   private <T> void setIdGeneration(DeployBeanDescriptor<T> desc) {
 
+    if (desc.getIdGenerator() != null) {
+      // already assigned (So custom or UUID)
+      return;
+    }
     if (desc.propertiesId().size() == 0) {
       // bean doesn't have an Id property
       if (desc.isBaseTableType() && desc.getBeanFinder() == null) {
@@ -1209,14 +1211,6 @@ public class BeanDescriptorManager implements BeanDescriptorMap {
       desc.setIdTypePlatformDefault();
     }
 
-    if (IdType.GENERATOR.equals(desc.getIdType())) {
-      String genName = desc.getIdGeneratorName();
-      if (UuidIdGenerator.AUTO_UUID.equals(genName)) {
-        desc.setIdGenerator(uuidIdGenerator);
-        return;
-      }
-    }
-
     if (desc.getBaseTable() == null) {
       // no base table so not going to set Identity
       // of sequence information
@@ -1240,8 +1234,7 @@ public class BeanDescriptorManager implements BeanDescriptorMap {
     }
 
     // create the sequence based IdGenerator
-    PlatformIdGenerator seqIdGen = createSequenceIdGenerator(seqName);
-    desc.setIdGenerator(seqIdGen);
+    desc.setIdGenerator(createSequenceIdGenerator(seqName));
   }
 
   private PlatformIdGenerator createSequenceIdGenerator(String seqName) {

src/main/java/com/avaje/ebeaninternal/server/deploy/generatedproperty/GeneratedPropertyFactory.java

@@ -1,12 +1,18 @@
 package com.avaje.ebeaninternal.server.deploy.generatedproperty;
 
+import com.avaje.ebean.Transaction;
 import com.avaje.ebean.config.ClassLoadConfig;
 import com.avaje.ebean.config.CurrentUserProvider;
+import com.avaje.ebean.config.IdGenerator;
 import com.avaje.ebean.config.ServerConfig;
+import com.avaje.ebean.config.dbplatform.PlatformIdGenerator;
 import com.avaje.ebeaninternal.server.deploy.meta.DeployBeanProperty;
 
 import java.math.BigDecimal;
+import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
 
 /**
  * Default implementation of GeneratedPropertyFactory.
@@ -27,7 +33,9 @@ public class GeneratedPropertyFactory {
 
   private final ClassLoadConfig classLoadConfig;
 
-  public GeneratedPropertyFactory(ServerConfig serverConfig) {
+  private final Map<String,PlatformIdGenerator> idGeneratorMap = new HashMap<String,PlatformIdGenerator>();
+
+  public GeneratedPropertyFactory(ServerConfig serverConfig, List<IdGenerator> idGenerators) {
 
     this.classLoadConfig = serverConfig.getClassLoadConfig();
     this.insertFactory = new InsertTimestampFactory(classLoadConfig);
@@ -51,6 +59,12 @@ public class GeneratedPropertyFactory {
     numberTypes.add(Double.class.getName());
     numberTypes.add(double.class.getName());
     numberTypes.add(BigDecimal.class.getName());
+
+    if (idGenerators != null) {
+      for (IdGenerator idGenerator : idGenerators) {
+        idGeneratorMap.put(idGenerator.getName(), new CustomIdGenerator(idGenerator));
+      }
+    }
   }
 
   public ClassLoadConfig getClassLoadConfig() {
@@ -98,4 +112,42 @@ public class GeneratedPropertyFactory {
     property.setGeneratedProperty(generatedWhoModified);
   }
 
+  /**
+   * Return the named custom IdGenerator (wrapped as a PlatformIdGenerator).
+   */
+  public PlatformIdGenerator getIdGenerator(String generatorName) {
+    return idGeneratorMap.get(generatorName);
+  }
+
+  /**
+   * Wraps the custom IdGenerator to implement PlatformIdGenerator.
+   */
+  private static class CustomIdGenerator implements PlatformIdGenerator {
+
+    private final IdGenerator generator;
+
+    CustomIdGenerator(IdGenerator generator) {
+      this.generator = generator;
+    }
+
+    @Override
+    public String getName() {
+      return generator.getName();
+    }
+
+    @Override
+    public boolean isDbSequence() {
+      return false;
+    }
+
+    @Override
+    public Object nextId(Transaction transaction) {
+      return generator.nextValue();
+    }
+
+    @Override
+    public void preAllocateIds(int allocateSize) {
+      // do nothing
+    }
+  }
 }

src/main/java/com/avaje/ebeaninternal/server/deploy/meta/DeployBeanDescriptor.java

@@ -29,6 +29,7 @@ import com.avaje.ebeaninternal.server.deploy.DeployNamedQuery;
 import com.avaje.ebeaninternal.server.deploy.DeployNamedUpdate;
 import com.avaje.ebeaninternal.server.deploy.InheritInfo;
 import com.avaje.ebeaninternal.server.deploy.parse.DeployBeanInfo;
+import com.avaje.ebeaninternal.server.idgen.UuidIdGenerator;
 
 import javax.persistence.Entity;
 import javax.persistence.MappedSuperclass;
@@ -830,6 +831,24 @@ public class DeployBeanDescriptor<T> {
     }
   }
 
+  /**
+   * Assign the standard UUID generator.
+   */
+  public void setUuidGenerator() {
+    this.idType = IdType.EXTERNAL;
+    this.idGeneratorName = UuidIdGenerator.AUTO_UUID;
+    this.idGenerator = UuidIdGenerator.INSTANCE;
+  }
+
+  /**
+   * Assign a custom external IdGenerator.
+   */
+  public void setCustomIdGenerator(PlatformIdGenerator idGenerator) {
+    this.idType = IdType.EXTERNAL;
+    this.idGeneratorName = idGenerator.getName();
+    this.idGenerator = idGenerator;
+  }
+
   /**
    * Summary description.
    */

src/main/java/com/avaje/ebeaninternal/server/deploy/parse/AnnotationFields.java

@@ -6,12 +6,12 @@ import com.avaje.ebean.config.EncryptDeploy.Mode;
 import com.avaje.ebean.config.dbplatform.DbEncrypt;
 import com.avaje.ebean.config.dbplatform.DbEncryptFunction;
 import com.avaje.ebean.config.dbplatform.IdType;
+import com.avaje.ebean.config.dbplatform.PlatformIdGenerator;
 import com.avaje.ebeaninternal.server.deploy.generatedproperty.GeneratedPropertyFactory;
 import com.avaje.ebeaninternal.server.deploy.meta.DeployBeanProperty;
 import com.avaje.ebeaninternal.server.deploy.meta.DeployBeanPropertyAssoc;
 import com.avaje.ebeaninternal.server.deploy.meta.DeployBeanPropertyAssocOne;
 import com.avaje.ebeaninternal.server.deploy.meta.DeployBeanPropertyCompound;
-import com.avaje.ebeaninternal.server.idgen.UuidIdGenerator;
 import com.avaje.ebeaninternal.server.lib.util.StringHelper;
 import com.avaje.ebeaninternal.server.type.CtCompoundType;
 import com.avaje.ebeaninternal.server.type.DataEncryptSupport;
@@ -419,12 +419,8 @@ public class AnnotationFields extends AnnotationParser {
     prop.setNullable(false);
 
     if (prop.getPropertyType().equals(UUID.class)) {
-      // An Id of type UUID
       if (descriptor.getIdGeneratorName() == null) {
-        // Without a generator explicitly specified
-        // so will use the default one AUTO_UUID
-        descriptor.setIdGeneratorName(UuidIdGenerator.AUTO_UUID);
-        descriptor.setIdType(IdType.GENERATOR);
+        descriptor.setUuidGenerator();
       }
     }
   }
@@ -449,14 +445,20 @@ public class AnnotationFields extends AnnotationParser {
 
     } else if (strategy == GenerationType.SEQUENCE) {
       descriptor.setIdType(IdType.SEQUENCE);
-      if (genName != null && genName.length() > 0) {
+      if (!genName.equals("")) {
         descriptor.setIdGeneratorName(genName);
       }
 
     } else if (strategy == GenerationType.AUTO) {
-      if (prop.getPropertyType().equals(UUID.class)) {
-        descriptor.setIdGeneratorName(UuidIdGenerator.AUTO_UUID);
-        descriptor.setIdType(IdType.GENERATOR);
+      if (!genName.equals("")) {
+        // use a custom IdGenerator
+        PlatformIdGenerator idGenerator = generatedPropFactory.getIdGenerator(genName);
+        if (idGenerator == null) {
+          throw new IllegalStateException("No custom IdGenerator registered with name "+genName);
+        }
+        descriptor.setCustomIdGenerator(idGenerator);
+      } else if (prop.getPropertyType().equals(UUID.class)) {
+        descriptor.setUuidGenerator();
       }
     }
   }

src/main/java/com/avaje/ebeaninternal/server/idgen/UuidIdGenerator.java

@@ -1,41 +1,43 @@
 package com.avaje.ebeaninternal.server.idgen;
 
-import java.util.UUID;
-
 import com.avaje.ebean.Transaction;
 import com.avaje.ebean.config.dbplatform.PlatformIdGenerator;
 
+import java.util.UUID;
+
 /**
  * IdGenerator for java util UUID.
  */
 public class UuidIdGenerator implements PlatformIdGenerator {
 
-	/**
-	 * Return UUID from UUID.randomUUID();
-	 */
-	public Object nextId(Transaction t) {
-		return UUID.randomUUID();
-	}
+  public static UuidIdGenerator INSTANCE = new UuidIdGenerator();
 
-	/**
-	 * Returns "uuid".
-	 */
-	public String getName() {
-		return "uuid";
-	}
+  /**
+   * Return UUID from UUID.randomUUID();
+   */
+  public Object nextId(Transaction t) {
+    return UUID.randomUUID();
+  }
 
-	/**
-	 * Returns false.
-	 */
-	public boolean isDbSequence() {
-		return false;
-	}
+  /**
+   * Returns "uuid".
+   */
+  public String getName() {
+    return "uuid";
+  }
 
-	/**
-	 * Ignored for UUID as not required as a performance optimisation.
-	 */
-	public void preAllocateIds(int allocateSize) {
-		// ignored
-	}
+  /**
+   * Returns false.
+   */
+  public boolean isDbSequence() {
+    return false;
+  }
+
+  /**
+   * Ignored for UUID as not required as a performance optimisation.
+   */
+  public void preAllocateIds(int allocateSize) {
+    // ignored
+  }
 
 }