#2134 - Modify ChangeLog to send the last set of changes Pre Commit (rather than post commit). Expose this for spring transactions.

ebean-core/src/main/java/io/ebeaninternal/api/SpiTransaction.java

@@ -319,6 +319,11 @@ public interface SpiTransaction extends Transaction {
    */
   boolean isSkipCacheExplicit();
 
+  /**
+   * Fire pre commit processing/listeners.
+   */
+  void preCommit();
+
   /**
    * Fire post commit events and listeners.
    */

ebean-core/src/main/java/io/ebeaninternal/api/SpiTransactionProxy.java

@@ -418,6 +418,11 @@ public abstract class SpiTransactionProxy implements SpiTransaction {
     transaction.flushBatchOnCollection();
   }
 
+  @Override
+  public void preCommit() {
+    transaction.preCommit();
+  }
+
   @Override
   public void postCommit() {
     transaction.postCommit();

ebean-core/src/main/java/io/ebeaninternal/server/transaction/ImplicitReadOnlyTransaction.java

@@ -586,6 +586,11 @@ class ImplicitReadOnlyTransaction implements SpiTransaction, TxnProfileEventCode
     }
   }
 
+  @Override
+  public void preCommit() {
+    // do nothing
+  }
+
   @Override
   public void postCommit() {
     // do nothing

ebean-core/src/main/java/io/ebeaninternal/server/transaction/JdbcTransaction.java

@@ -373,6 +373,9 @@ class JdbcTransaction implements SpiTransaction, TxnProfileEventCodes {
 
   private void firePreCommit() {
     withEachCallback(TransactionCallback::preCommit);
+    if (changeLogHolder != null) {
+      changeLogHolder.preCommit();
+    }
   }
 
   private void firePostCommit() {
@@ -981,9 +984,7 @@ class JdbcTransaction implements SpiTransaction, TxnProfileEventCodes {
    * Batch flush, jdbc commit, trigger registered TransactionCallbacks, notify l2 cache etc.
    */
   private void flushCommitAndNotify() throws SQLException {
-    internalBatchFlush();
-    firePreCommit();
-    // only performCommit can throw an exception
+    preCommit();
     performCommit();
     postCommit();
   }
@@ -994,6 +995,12 @@ class JdbcTransaction implements SpiTransaction, TxnProfileEventCodes {
     notifyCommit();
   }
 
+  @Override
+  public void preCommit() {
+    internalBatchFlush();
+    firePreCommit();
+  }
+
   /**
    * Perform a commit, fire callbacks and notify l2 cache etc.
    * <p>

ebean-core/src/main/java/io/ebeaninternal/server/transaction/JtaTransactionManager.java

@@ -190,7 +190,7 @@ public class JtaTransactionManager implements ExternalTransactionManager {
 
     @Override
     public void beforeCompletion() {
-      transaction.flush();
+      transaction.preCommit();
     }
 
     @Override

ebean-core/src/main/java/io/ebeaninternal/server/transaction/NoTransaction.java

@@ -88,6 +88,11 @@ class NoTransaction implements SpiTransaction {
     // do nothing
   }
 
+  @Override
+  public void preCommit() {
+    // do nothing
+  }
+
   @Override
   public void postCommit() {
     // do nothing

ebean-core/src/main/java/io/ebeaninternal/server/transaction/TChangeLogHolder.java

@@ -56,20 +56,31 @@ public class TChangeLogHolder {
    * Add a bean change to the change set.
    */
   public void addBeanChange(BeanChange change) {
-
     changes.addBeanChange(change);
     if (++count >= batchSize) {
       // we hit the batch size so send what we have knowing
       // that the transaction has not completed yet and
       // reset the changes and count
-      owner.sendChangeLog(changes);
-      changes = new ChangeSet(transactionId, ++batchId);
-      count = 0;
+      sendChanges();
     }
   }
 
+  private void sendChanges() {
+    owner.sendChangeLog(changes);
+    changes = new ChangeSet(transactionId, ++batchId);
+    count = 0;
+  }
+
   /**
-   * On post commit send the changes we have collected.
+   * Send the changes held prior to transaction commit.
+   */
+  public void preCommit() {
+    sendChanges();
+  }
+
+  /**
+   * On post commit send the changes we have collected. This should be
+   * only the COMMITTED state and with all changes sent prior to commit.
    */
   public void postCommit() {
     changes.setTxnState(TxnState.COMMITTED);