1 files changed, 74 insertions, 0 deletions
diff --git a/sca-java-1.x/tags/java-stable-20060304/spec/sdo/src/main/java/commonj/sdo/impl/ExternalizableDelegator.java b/sca-java-1.x/tags/java-stable-20060304/spec/sdo/src/main/java/commonj/sdo/impl/ExternalizableDelegator.java
new file mode 100644
index 0000000000..a833bb63a9
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+++ b/sca-java-1.x/tags/java-stable-20060304/spec/sdo/src/main/java/commonj/sdo/impl/ExternalizableDelegator.java
@@ -0,0 +1,74 @@
+package commonj.sdo.impl;
+
+import java.io.Externalizable;
+import java.io.IOException;
+import java.io.ObjectInput;
+import java.io.ObjectOutput;
+import java.io.ObjectStreamException;
+
+/**
+ * Delegates DataObject serialization while ensuring implementation independent 
+ * java.io.Serialization.  An implementation of DataObject
+ * returns an ExternalizableDelegator from its writeReplace() method.
+ * 
+ * The root DataObject is the object returned from do.getRootObject() where
+ *   do is the DataObject being serialized in a java.io.ObjectOutputStream.
+ *   When do.getContainer() == null then do is a root object.
+ * 
+ * The byte format for each DataObject in the stream is:
+ * [0] [path] [root]   // when do is not a root object
+ * [1] [rootXML]       // when do is a root object
+ * 
+ * where:
+ * [0] is the byte 0, serialized using writeByte(0).
+ * [1] is the byte 1, serialized using writeByte(1).
+ *   
+ * [path] is an SDO path expression from the root DataObject to the serialized 
+ *          DataObject such that root.getDataObject(path) == do.
+ *          Serialized using writeUTF(path).
+ * 
+ * [root] is the root object serialized using writeObject(root).
+ * 
+ * [rootXML] is the GZip of the XML serialization of the root DataObject.
+ *          The XML serialization is the same as 
+ *          XMLHelper.INSTANCE.save(root, "commonj.sdo", "dataObject", stream);
+ *          where stream is a GZIPOutputStream, length is the number of bytes 
+ *          in the stream, and bytes are the contents of the stream.
+ *          Serialized using writeInt(length), write(bytes).
+ *
+ */
+public class ExternalizableDelegator implements Externalizable
+{
+  public interface Resolvable extends Externalizable
+  {
+    Object readResolve() throws ObjectStreamException;
+  }
+  
+  static final long serialVersionUID = 1;
+  transient Resolvable delegate;
+  
+  public ExternalizableDelegator()
+  {
+    delegate = HelperProvider.createResolvable();
+  }
+
+  public ExternalizableDelegator(Object target)
+  {
+    delegate = HelperProvider.createResolvable(target);
+  }
+
+  public void writeExternal(ObjectOutput out) throws IOException
+  {
+    delegate.writeExternal(out);
+  }
+
+  public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException
+  {
+    delegate.readExternal(in);
+  }
+
+  public Object readResolve() throws ObjectStreamException
+  {
+    return delegate.readResolve();
+  }
+}