Fix #169 (actual main fix in jackson-databind)

Author: cowtowncoder

pom.xml

@@ -25,8 +25,8 @@ Some data-binding types overridden as well (ObjectMapper sub-classed as XmlMappe
   </scm>
   <properties>
     <version.jackson.annotations>2.7.0-rc2</version.jackson.annotations>
-    <version.jackson.core>2.7.0-rc2</version.jackson.core>
-    <version.jackson.jaxb>${version.jackson.core}</version.jackson.jaxb>
+    <version.jackson.core>2.7.0-rc3-SNAPSHOT</version.jackson.core>
+    <version.jackson.jaxb>2.7.0-rc2</version.jackson.jaxb>
     <packageVersion.dir>com/fasterxml/jackson/dataformat/xml</packageVersion.dir>
     <packageVersion.package>${project.groupId}.xml</packageVersion.package>
 

release-notes/VERSION

@@ -7,6 +7,7 @@ Project: jackson-dataformat-xml
 2.7.0 (not yet released)
 
 #156: Add `XmlMapper.setDefaultUseWrapper()` for convenience.
+#169: Fail to deserialize "empty" polymorphic classes
 
 2.6.4 (not yet released)
 

src/main/java/com/fasterxml/jackson/dataformat/xml/deser/FromXmlParser.java

@@ -203,7 +203,7 @@ public void setXMLTextElementName(String name) {
      */
     @Override
     public boolean requiresCustomCodec() {
-        return false;
+        return true;
     }
 
     /*

src/test/java/com/fasterxml/jackson/dataformat/xml/misc/EmptyPolymorphicTest.java

@@ -0,0 +1,46 @@
+package com.fasterxml.jackson.dataformat.xml.misc;
+
+import com.fasterxml.jackson.annotation.*;
+
+import com.fasterxml.jackson.dataformat.xml.XmlMapper;
+import com.fasterxml.jackson.dataformat.xml.XmlTestBase;
+
+// test(s) for [dataformat-xml#111]
+public class EmptyPolymorphicTest extends XmlTestBase
+{
+    static class Data {
+        public String name;
+
+        @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.WRAPPER_OBJECT)
+        @JsonSubTypes({ @JsonSubTypes.Type(EmptyProxy.class) })
+        public Proxy proxy;
+
+        public Data() { }
+        public Data(String n) {
+            name = n;
+            proxy = new EmptyProxy();
+        }
+    }
+
+    static interface Proxy { }
+
+    @JsonTypeName("empty")
+    static class EmptyProxy implements Proxy { }
+
+    /*
+    /**********************************************************
+    /* Test methods
+    /**********************************************************
+     */
+    
+    protected XmlMapper MAPPER = new XmlMapper();
+    
+    public void testEmpty() throws Exception
+    {
+        String xml = MAPPER.writerWithDefaultPrettyPrinter().writeValueAsString(new Data("Foobar"));
+        System.out.println("XML:\n"+xml);
+        final Data data = MAPPER.readValue(xml, Data.class);
+//                "<data><name>Foobar</name><proxy><empty></empty></proxy></data>"
+        assertNotNull(data);
+    }
+}

src/test/java/com/fasterxml/jackson/dataformat/xml/misc/PolymorphicTypesTest.java

@@ -26,7 +26,7 @@ static class SubTypeWithClassProperty extends BaseTypeWithClassProperty {
         public SubTypeWithClassProperty() { }
         public SubTypeWithClassProperty(String s) { name = s; }
     }
-    
+
     @JsonTypeInfo(use=JsonTypeInfo.Id.CLASS, include=JsonTypeInfo.As.WRAPPER_OBJECT)
     protected static class BaseTypeWithClassObject { }
 
@@ -67,7 +67,7 @@ public void setUp() throws Exception {
         super.setUp();
         _xmlMapper = new XmlMapper();
     }
-    
+
     /*
     /**********************************************************
     /* Unit tests
@@ -79,9 +79,6 @@ public void testAsClassProperty() throws Exception
         String xml = _xmlMapper.writeValueAsString(new SubTypeWithClassProperty("Foobar"));
 
         // Type info should be written as an attribute, so:
-        /* 13-Jan-2010, tatu: With Jackson 1.7.1, it is possible to override type information
-         *   inclusion, which allows use of attribute over element, so:
-         */
         final String exp = 
             "<SubTypeWithClassProperty _class=\"com.fasterxml.jackson.dataformat.xml.misc.PolymorphicTypesTest..SubTypeWithClassProperty\">"
             //"<SubTypeWithClassProperty><_class>com.fasterxml.jackson.xml.types.TestPolymorphic..SubTypeWithClassProperty</_class>"
@@ -105,7 +102,7 @@ public void testAsClassObject() throws Exception
     }
 
     /**
-     * Test for issue 81
+     * Test for [dataformat-xml#81]
      */
     public void testAsPropertyWithObjectId() throws Exception
     {