#1390 - ENH: Support explicit @Id @GeneratedValue ... mapping (where absence of @GeneratedValue means externally supplied id values)

src/main/java/io/ebean/config/ServerConfig.java

@@ -493,6 +493,11 @@ public class ServerConfig {
    */
   private List<String> mappingLocations = new ArrayList<>();
 
+  /**
+   * When true we do not need explicit GeneratedValue mapping.
+   */
+  private boolean idGeneratorAutomatic = true;
+
   /**
    * Construct a Server Configuration for programmatically creating an EbeanServer.
    */
@@ -1967,7 +1972,7 @@ public class ServerConfig {
    * This is the same as serverConfig.getMigrationConfig().setRunMigration(). We have added this method here
    * as it is often the only thing we need to configure for migrations.
    */
-  public void setRunMigration(boolean runMigration){
+  public void setRunMigration(boolean runMigration) {
     migrationConfig.setRunMigration(runMigration);
   }
 
@@ -2772,6 +2777,7 @@ public class ServerConfig {
     useJtaTransactionManager = p.getBoolean("useJtaTransactionManager", useJtaTransactionManager);
     useJavaxValidationNotNull = p.getBoolean("useJavaxValidationNotNull", useJavaxValidationNotNull);
     autoReadOnlyDataSource = p.getBoolean("autoReadOnlyDataSource", autoReadOnlyDataSource);
+    idGeneratorAutomatic = p.getBoolean("idGeneratorAutomatic", idGeneratorAutomatic);
 
     backgroundExecutorSchedulePoolSize = p.getInt("backgroundExecutorSchedulePoolSize", backgroundExecutorSchedulePoolSize);
     backgroundExecutorShutdownSecs = p.getInt("backgroundExecutorShutdownSecs", backgroundExecutorShutdownSecs);
@@ -3109,6 +3115,23 @@ public class ServerConfig {
     this.mappingLocations = mappingLocations;
   }
 
+  /**
+   * When false we need explicit <code>@GeneratedValue</code> mapping to assign
+   * Identity or Sequence generated values. When true Id properties are automatically
+   * assigned Identity or Sequence without the GeneratedValue mapping.
+   */
+  public boolean isIdGeneratorAutomatic() {
+    return idGeneratorAutomatic;
+  }
+
+  /**
+   * Set to false such that Id properties require explicit <code>@GeneratedValue</code>
+   * mapping before they are assigned Identity or Sequence generation based on platform.
+   */
+  public void setIdGeneratorAutomatic(boolean idGeneratorAutomatic) {
+    this.idGeneratorAutomatic = idGeneratorAutomatic;
+  }
+
   public enum UuidVersion {
     VERSION4,
     VERSION1,

src/main/java/io/ebeaninternal/server/deploy/BeanDescriptorManager.java

@@ -1369,9 +1369,15 @@ public class BeanDescriptorManager implements BeanDescriptorMap {
         desc.setIdType(IdType.EXTERNAL);
         return;
       }
-      // use the default. IDENTITY or SEQUENCE.
-      desc.setIdType(dbIdentity.getIdType());
-      desc.setIdTypePlatformDefault();
+      if (desc.isIdGeneratorAuto() || serverConfig.isIdGeneratorAutomatic()) {
+        // use IDENTITY or SEQUENCE based on platform
+        desc.setIdType(dbIdentity.getIdType());
+        desc.setIdTypePlatformDefault();
+      } else {
+        // externally/application supplied Id values
+        desc.setIdType(IdType.EXTERNAL);
+        return;
+      }
     }
 
     if (desc.getBaseTable() == null) {
@@ -1387,21 +1393,23 @@ public class BeanDescriptorManager implements BeanDescriptorMap {
       return;
     }
 
-    String seqName = desc.getIdGeneratorName();
-    if (seqName != null) {
-      logger.debug("explicit sequence {} on {}", seqName, desc.getFullName());
-    } else {
-      String primaryKeyColumn = desc.getSinglePrimaryKeyColumn();
-      // use namingConvention to define sequence name
-      seqName = namingConvention.getSequenceName(desc.getBaseTable(), primaryKeyColumn);
-    }
+    if (IdType.SEQUENCE == desc.getIdType()) {
+      String seqName = desc.getIdGeneratorName();
+      if (seqName != null) {
+        logger.debug("explicit sequence {} on {}", seqName, desc.getFullName());
+      } else {
+        String primaryKeyColumn = desc.getSinglePrimaryKeyColumn();
+        // use namingConvention to define sequence name
+        seqName = namingConvention.getSequenceName(desc.getBaseTable(), primaryKeyColumn);
+      }
 
-    if (databasePlatform.isSequenceBatchMode()) {
-      // use sequence next step 1 as we are going to batch fetch them instead
-      desc.setSequenceAllocationSize(1);
+      if (databasePlatform.isSequenceBatchMode()) {
+        // use sequence next step 1 as we are going to batch fetch them instead
+        desc.setSequenceAllocationSize(1);
+      }
+      int stepSize = desc.getSequenceAllocationSize();
+      desc.setIdGenerator(createSequenceIdGenerator(seqName, stepSize));
     }
-    int stepSize = desc.getSequenceAllocationSize();
-    desc.setIdGenerator(createSequenceIdGenerator(seqName, stepSize));
   }
 
   private PlatformIdGenerator createSequenceIdGenerator(String seqName, int stepSize) {

src/main/java/io/ebeaninternal/server/deploy/meta/DeployBeanDescriptor.java

@@ -106,6 +106,11 @@ public class DeployBeanDescriptor<T> {
 
   private PlatformIdGenerator idGenerator;
 
+  /**
+   * Set true when explicit auto generated Id.
+   */
+  private boolean idGeneratorAuto;
+
   /**
    * The database sequence name (optional).
    */
@@ -848,6 +853,20 @@ public class DeployBeanDescriptor<T> {
     }
   }
 
+  /**
+   * Return true for automatic Id generation strategy.
+   */
+  public boolean isIdGeneratorAuto() {
+    return idGeneratorAuto;
+  }
+
+  /**
+   * Set when GeneratedValue explicitly mapped on Id property.
+   */
+  public void setGeneratedAuto() {
+    this.idGeneratorAuto = true;
+  }
+
   /**
    * Assign the standard UUID generator.
    */

src/main/java/io/ebeaninternal/server/deploy/parse/AnnotationFields.java

@@ -547,6 +547,8 @@ public class AnnotationFields extends AnnotationParser {
         descriptor.setCustomIdGenerator(idGenerator);
       } else if (prop.getPropertyType().equals(UUID.class)) {
         descriptor.setUuidGenerator();
+      } else {
+        descriptor.setGeneratedAuto();
       }
     }
   }