defined an annotation to control Mapper.serializeAs

xstream/src/java/com/thoughtworks/xstream/annotations/XStreamSerializeAs.java

@@ -0,0 +1,25 @@
+package com.thoughtworks.xstream.annotations;
+
+import java.lang.annotation.Inherited;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.*;
+import static java.lang.annotation.RetentionPolicy.*;
+
+/**
+ * Designates that the type and its derived types will serialize
+ * as the specified type. This is useful if you want an entire
+ * family of types serialize as the base type with its special converter.
+ *
+ * @author Kohsuke Kawaguchi
+ */
+@Retention(RUNTIME)
+@Target(TYPE)
+@Inherited
+public @interface XStreamSerializeAs {
+    /**
+     * Use {@code void.class} to cancel out the annotation defined in the super type.
+     */
+    Class<?> value();
+}

xstream/src/java/com/thoughtworks/xstream/mapper/AnnotationMapper.java

@@ -20,6 +20,7 @@
 import com.thoughtworks.xstream.annotations.XStreamImplicitCollection;
 import com.thoughtworks.xstream.annotations.XStreamInclude;
 import com.thoughtworks.xstream.annotations.XStreamOmitField;
+import com.thoughtworks.xstream.annotations.XStreamSerializeAs;
 import com.thoughtworks.xstream.converters.Converter;
 import com.thoughtworks.xstream.converters.ConverterMatcher;
 import com.thoughtworks.xstream.converters.ConverterRegistry;
@@ -68,6 +69,8 @@ public class AnnotationMapper extends MapperWrapper implements AnnotationConfigu
     private final Map<Class<?>, Converter> converterCache = new HashMap<Class<?>, Converter>();
     private final Set<Class<?>> annotatedTypes = new WeakHashSet<Class<?>>();
 
+    private final Map<Class,String> serializedClass = new WeakHashMap<Class, String>();
+
     /**
      * Construct an AnnotationMapper.
      * 
@@ -104,6 +107,8 @@ public String serializedClass(final Class type) {
         if (!locked) {
             processAnnotations(type);
         }
+        String name = serializedClass.get(type);
+        if (name!=null) return name;
         return super.serializedClass(type);
     }
 
@@ -167,6 +172,10 @@ private void processTypes(final Set<Class<?>> types) {
                     continue;
                 }
 
+                XStreamSerializeAs a = type.getAnnotation(XStreamSerializeAs.class);
+                if (a!=null && a.value()!=void.class)
+                    serializedClass.put(type,a.value().getName());
+
                 addParametrizedTypes(type, types);
 
                 processConverterAnnotations(type);