#919 - io.ebean package initial

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

@@ -0,0 +1,42 @@
+package io.ebeaninternal.server.deploy;
+
+import java.util.Collection;
+import java.util.Map;
+
+import javax.persistence.PersistenceException;
+
+import io.ebean.bean.BeanCollection;
+
+/**
+ * Utility methods for BeanCollections.
+ */
+public class BeanCollectionUtil {
+
+  /**
+   * Return the details of the collection or map taking care to avoid
+   * unnecessary fetching of the data.
+   */
+  public static Collection<?> getActualEntries(Object o) {
+    if (o == null) {
+      return null;
+    }
+    if (o instanceof BeanCollection<?>) {
+      BeanCollection<?> bc = (BeanCollection<?>) o;
+      if (!bc.isPopulated()) {
+        return null;
+      }
+      // For maps this is a collection of Map.Entry, otherwise it
+      // returns a collection of beans
+      return bc.getActualEntries();
+    }
+
+    if (o instanceof Map<?, ?>) {
+      // yes, we want the entrySet (to set the keys)
+      return ((Map<?, ?>) o).entrySet();
+
+    } else if (o instanceof Collection<?>) {
+      return ((Collection<?>) o);
+    }
+    throw new PersistenceException("expecting a Map or Collection but got [" + o.getClass().getName() + "]");
+  }
+}