NEW: PersistVisitor

ebean-core/src/main/java/io/ebeaninternal/server/core/DefaultServer.java

@@ -18,6 +18,7 @@ import io.ebean.FutureRowCount;
 import io.ebean.MergeOptions;
 import io.ebean.MergeOptionsBuilder;
 import io.ebean.PagedList;
+import io.ebean.PersistVisitor;
 import io.ebean.PersistenceContextScope;
 import io.ebean.ProfileLocation;
 import io.ebean.Query;
@@ -1628,6 +1629,11 @@ public final class DefaultServer implements SpiServer, SpiEbeanServer {
     persister.save(checkEntityBean(bean), transaction);
   }
 
+  @Override
+  public void visitSave(Object start, PersistVisitor visitor) {
+    new VisitHandler(descriptorManager).visit(start, visitor);
+  }
+
   @Override
   public void markAsDirty(Object bean) {
     if (!(bean instanceof EntityBean)) {

ebean-core/src/main/java/io/ebeaninternal/server/core/VisitHandler.java

@@ -0,0 +1,121 @@
+package io.ebeaninternal.server.core;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.IdentityHashMap;
+import java.util.Map;
+import java.util.Set;
+
+import io.ebean.PersistVisitor;
+import io.ebean.bean.EntityBean;
+import io.ebean.bean.EntityBeanIntercept;
+import io.ebeaninternal.server.deploy.BeanDescriptor;
+import io.ebeaninternal.server.deploy.BeanDescriptorManager;
+import io.ebeaninternal.server.deploy.BeanPropertyAssocMany;
+import io.ebeaninternal.server.deploy.BeanPropertyAssocOne;
+
+/**
+ * Handler to process persist graphs. It will allow you to visit a persist
+ * action (insert/update) and get information about all beans that will be
+ * affected by that action. This allows you to do validation and other things on
+ * a set of beans.
+ * 
+ * @author Roland Praml, FOCONIS AG
+ *
+ */
+class VisitHandler {
+
+  private final Set<Object> seen = Collections.newSetFromMap(new IdentityHashMap<Object, Boolean>());
+  private final BeanDescriptorManager beanDescriptorManager;
+
+  public VisitHandler(BeanDescriptorManager beanDescriptorManager) {
+    this.beanDescriptorManager = beanDescriptorManager;
+  }
+
+  public void visit(Object start, PersistVisitor visitor) {
+    if (start != null) {
+      if (start instanceof EntityBean) {
+        visitBean((EntityBean) start, visitor);
+      } else {
+        visitMany(start, visitor);
+      }
+    }
+    visitor.visitEnd();
+  }
+
+  private void visitBean(EntityBean bean, PersistVisitor visitor) {
+    if (!seen.add(bean)) {
+      return;
+    }
+    visitor = visitor.visitBean(bean);
+    if (visitor != null) {
+      BeanDescriptor<?> desc = beanDescriptorManager.descriptor(bean.getClass());
+      visitOnes(bean, visitor, desc, desc.propertiesOneImportedSave());
+      visitOnes(bean, visitor, desc, desc.propertiesOneExportedSave());
+      visitManys(bean, visitor, desc, desc.propertiesManySave());
+      visitor.visitEnd();
+    }
+  }
+
+  private void visitManys(EntityBean bean, PersistVisitor visitor, BeanDescriptor<?> desc,
+      BeanPropertyAssocMany<?>[] manys) {
+    EntityBeanIntercept ebi = bean._ebean_getIntercept();
+    for (BeanPropertyAssocMany<?> many : manys) {
+      // check that property is loaded and collection should be cascaded to
+      if (ebi.isLoadedProperty(many.propertyIndex()) && !many.isSkipSaveBeanCollection(bean, ebi.isNew())) {
+        Object manyValue = many.getValue(bean);
+        if (manyValue != null) {
+          PersistVisitor propertyVisitor = visitor.visitProperty(many);
+          if (propertyVisitor != null) {
+            visitMany(manyValue, propertyVisitor);
+            propertyVisitor.visitEnd();
+          }
+        }
+      }
+    }
+  }
+
+  private void visitMany(Object many, PersistVisitor visitor) {
+    if (!seen.add(many)) {
+      return;
+    }
+    if (many instanceof Collection) {
+      Collection<?> coll = (Collection<?>) many;
+      PersistVisitor collectionVisitor = visitor.visitCollection(coll);
+      if (collectionVisitor != null) {
+        for (Object elem : coll) {
+          visitBean((EntityBean) elem, collectionVisitor);
+        }
+        collectionVisitor.visitEnd();
+      }
+    } else if (many instanceof Map) {
+      Map<?, ?> map = (Map<?, ?>) many;
+      PersistVisitor mapVisitor = visitor.visitMap(map);
+      if (mapVisitor != null) {
+        for (Object elem : ((Map<?, ?>) many).values()) {
+          visitBean((EntityBean) elem, mapVisitor);
+        }
+        mapVisitor.visitEnd();
+      }
+    } else {
+      throw new IllegalArgumentException("Object " + many + " cannot be visited in persist graph");
+    }
+  }
+
+  private void visitOnes(EntityBean bean, PersistVisitor visitor, BeanDescriptor<?> desc,
+      BeanPropertyAssocOne<?>[] ones) {
+    EntityBeanIntercept ebi = bean._ebean_getIntercept();
+    for (BeanPropertyAssocOne<?> prop : ones) {
+      if (ebi.isLoadedProperty(prop.propertyIndex())) {
+        EntityBean detailBean = prop.getValueAsEntityBean(bean);
+        if (detailBean != null && !prop.isSaveRecurseSkippable(detailBean) && !prop.isReference(detailBean)) {
+          PersistVisitor propertyVisitor = visitor.visitProperty(prop);
+          if (propertyVisitor != null) {
+            visitBean(detailBean, propertyVisitor);
+            propertyVisitor.visitEnd();
+          }
+        }
+      }
+    }
+  }
+}