Some more work towards #2539 for 3.x -- still need tests

cowtowncoder · cowtowncoder · commit ed7d0a83b9bc · 2019-11-18T22:31:17.000-08:00
diff --git a/src/main/java/com/fasterxml/jackson/databind/DeserializationContext.java b/src/main/java/com/fasterxml/jackson/databind/DeserializationContext.java
@@ -499,6 +499,25 @@ public PropertyName findRootName(Class<?> rawRootType) {
         return _config.findRootName(this, rawRootType);
     }
 
+    /**
+     * Method that can be used to see whether there is an explicitly registered deserializer
+     * for given type: this is true for supported JDK types, as well as third-party types
+     * for which {@code Module} provides support but is NOT true (that is, returns {@code false})
+     * for POJO types for which {@code BeanDeserializer} is generated based on discovered
+     * properties.
+     *<p>
+     * Note that it is up to {@code Module}s to implement support for this method: some
+     * do (like basic {@code SimpleModule}).
+     *
+     * @param valueType Type-erased type to check
+     *
+     * @return True if this factory has explicit (non-POJO) deserializer for specified type,
+     *    or has a provider (of type {@link Deserializers}) that has.
+     */
+    public boolean hasExplicitDeserializerFor(Class<?> valueType) {
+        return _factory.hasExplicitDeserializerFor(this, valueType);
+    }
+
     /*
     /**********************************************************************
     /* Public API, value deserializer access
diff --git a/src/main/java/com/fasterxml/jackson/databind/jsontype/BasicPolymorphicTypeValidator.java b/src/main/java/com/fasterxml/jackson/databind/jsontype/BasicPolymorphicTypeValidator.java
@@ -6,6 +6,7 @@
 import com.fasterxml.jackson.databind.DatabindContext;
 import com.fasterxml.jackson.databind.JavaType;
 import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.DeserializationContext;
 
 /**
  * Standard {@link BasicPolymorphicTypeValidator} implementation that users may want
@@ -18,8 +19,6 @@
  * For example:
  *<pre>
  *</pre>
- *
- * @since 2.10
  */
 public class BasicPolymorphicTypeValidator
     extends PolymorphicTypeValidator.Base
@@ -166,8 +165,6 @@ public boolean match(DatabindContext ctxt, Class<?> clazz) {
          * @param matcher Custom matcher to apply to base type
          *
          * @return This Builder to allow call chaining
-         *
-         * @since 2.11
          */
         public Builder allowIfBaseType(final TypeMatcher matcher) {
             return _appendBaseMatcher(matcher);
@@ -268,8 +265,6 @@ public boolean match(DatabindContext ctxt, String clazzName) {
          * @param matcher Custom matcher to apply to resolved subtype
          *
          * @return This Builder to allow call chaining
-         *
-         * @since 2.11
          */
         public Builder allowIfSubType(final TypeMatcher matcher) {
             return _appendSubClassMatcher(matcher);
@@ -286,8 +281,6 @@ public Builder allowIfSubType(final TypeMatcher matcher) {
          * NOTE: not used with other Java collection types ({@link java.util.List}s,
          *    {@link java.util.Collection}s), mostly since use of generic types as polymorphic
          *    values is not (well) supported.
-         *
-         * @since 2.11
          */
         public Builder allowIfSubTypeIsArray() {
             return _appendSubClassMatcher(new TypeMatcher() {
@@ -316,14 +309,17 @@ public boolean match(DatabindContext ctxt, Class<?> clazz) {
          * NOTE: Modules need to provide support for detection so if 3rd party types do not seem to
          * be supported, Module in question may need to be updated to indicate existence of explicit
          * deserializers.
-         *
-         * @since 2.11
          */
         public Builder allowSubTypesWithExplicitDeserializer() {
             return _appendSubClassMatcher(new TypeMatcher() {
                 @Override
-                public boolean match(DatabindContext ctxt, Class<?> clazz) {
-                    return clazz.isArray();
+                public boolean match(DatabindContext ctxt, Class<?> valueType) {
+                    // First things first: "peel off" array type (since Array types are provided
+                    // by JDK and can not be gadget types)
+                    while (valueType.isArray()) {
+                        valueType = valueType.getComponentType();
+                    }
+                    return ((DeserializationContext) ctxt).hasExplicitDeserializerFor(valueType);
                 }
             });
         }
diff --git a/src/main/java/com/fasterxml/jackson/databind/jsontype/NoneShallPassValidator.java b/src/main/java/com/fasterxml/jackson/databind/jsontype/NoneShallPassValidator.java
@@ -3,10 +3,15 @@
 import com.fasterxml.jackson.databind.DatabindContext;
 import com.fasterxml.jackson.databind.JavaType;
 import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.util.ClassUtil;
 
 /**
  * Default {@link PolymorphicTypeValidator} used unless explicit one is constructed.
- * Denies use of all types so isn't very useful as base.
+ * Denies use of most types so isn't very useful as base, as it only allows:
+ * <ul>
+ *  <li>Enums
+ *   </li>
+ *  </ul>
  */
 public class NoneShallPassValidator
     extends PolymorphicTypeValidator
@@ -16,17 +21,12 @@ public class NoneShallPassValidator
 
     @Override
     public Validity validateBaseType(DatabindContext ctxt, JavaType baseType)
-            throws JsonMappingException {
-        /* 24-Apr-2019, tatu: We do need to make it restrictive, BUT... as of now
-         *    tests would fail; need to get back to that right after 2.10
-        return Validity.DENIED;
-        */
-        /*
-        if (baseType.hasRawClass(Object.class)) {
-            return Validity.DENIED;
-        }
-        */
-        return Validity.ALLOWED;
+            throws JsonMappingException
+    {
+        // Actually let's not block any particular base type, just mark as 
+        // indeterminate to only base on actual subtype
+        
+        return Validity.INDETERMINATE;
     }
     
     @Override
@@ -37,16 +37,29 @@ public Validity validateSubClassName(DatabindContext ctxt,
 
     @Override
     public Validity validateSubType(DatabindContext ctxt, JavaType baseType,
-            JavaType subType) {
-        /* 24-Apr-2019, tatu: We do need to make it restrictive, BUT... as of now
-         *    tests would fail; need to get back to that right after 2.10
-        return Validity.DENIED;
-        */
-        /*
-        if (baseType.hasRawClass(Object.class)) {
+            JavaType subType)
+    {
+        // Very small set of allowed types:
+        //
+        // 1. Enums
+        // 2. Primitives, their wrappers
+        
+        if (subType.isEnumType()) {
+            return Validity.ALLOWED;
+        }
+        if (ClassUtil.primitiveType(subType.getRawClass()) != null) {
+            return Validity.ALLOWED;
+        }
+
+        // But aside from that actually only allow if base type not too generic
+        final Class<?> rawBase = baseType.getRawClass();
+        if ((rawBase == Object.class)
+                || (rawBase == Object.class)
+                || (rawBase == Object.class)
+                ) {
             return Validity.DENIED;
         }
-        */
+
         return Validity.ALLOWED;
     }
 }
diff --git a/src/test/java/com/fasterxml/jackson/databind/jsontype/TestPropertyTypeInfo.java b/src/test/java/com/fasterxml/jackson/databind/jsontype/TestPropertyTypeInfo.java
@@ -6,6 +6,7 @@
 
 import com.fasterxml.jackson.databind.BaseMapTest;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.testutil.NoCheckSubTypeValidator;
 
 /**
  * Testing to verify that {@link JsonTypeInfo} works
@@ -81,36 +82,37 @@ static class OtherBean {
     /**********************************************************
      */
 
+    final ObjectMapper MAPPER = jsonMapperBuilder()
+            .polymorphicTypeValidator(new NoCheckSubTypeValidator())
+            .build();
+    
     public void testSimpleField() throws Exception
     {
-        ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(new FieldWrapperBean(new StringWrapper("foo")));
+        String json = MAPPER.writeValueAsString(new FieldWrapperBean(new StringWrapper("foo")));
 //System.out.println("JSON/field+object == "+json);
-        FieldWrapperBean bean = mapper.readValue(json, FieldWrapperBean.class);
+        FieldWrapperBean bean = MAPPER.readValue(json, FieldWrapperBean.class);
         assertNotNull(bean.value);
         assertEquals(StringWrapper.class, bean.value.getClass());
         assertEquals(((StringWrapper) bean.value).str, "foo");
     }
 
     public void testSimpleMethod() throws Exception
     {
-        ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(new FieldWrapperBean(new IntWrapper(37)));
+        String json = MAPPER.writeValueAsString(new FieldWrapperBean(new IntWrapper(37)));
 //System.out.println("JSON/method+object == "+json);
-        FieldWrapperBean bean = mapper.readValue(json, FieldWrapperBean.class);
+        FieldWrapperBean bean = MAPPER.readValue(json, FieldWrapperBean.class);
         assertNotNull(bean.value);
         assertEquals(IntWrapper.class, bean.value.getClass());
         assertEquals(((IntWrapper) bean.value).i, 37);
     }
 
     public void testSimpleListField() throws Exception
     {
-        ObjectMapper mapper = new ObjectMapper();
         FieldWrapperBeanList list = new FieldWrapperBeanList();
         list.add(new FieldWrapperBean(new OtherBean()));
-        String json = mapper.writeValueAsString(list);
+        String json = MAPPER.writeValueAsString(list);
 //System.out.println("JSON/field+list == "+json);
-        FieldWrapperBeanList result = mapper.readValue(json, FieldWrapperBeanList.class);
+        FieldWrapperBeanList result = MAPPER.readValue(json, FieldWrapperBeanList.class);
         assertNotNull(result);
         assertEquals(1, result.size());
         FieldWrapperBean bean = list.get(0);
@@ -121,13 +123,12 @@ public void testSimpleListField() throws Exception
 
     public void testSimpleListMethod() throws Exception
     {
-        ObjectMapper mapper = new ObjectMapper();
         MethodWrapperBeanList list = new MethodWrapperBeanList();
         list.add(new MethodWrapperBean(new BooleanValue(true)));
         list.add(new MethodWrapperBean(new StringWrapper("x")));
         list.add(new MethodWrapperBean(new OtherBean()));
-        String json = mapper.writeValueAsString(list);
-        MethodWrapperBeanList result = mapper.readValue(json, MethodWrapperBeanList.class);
+        String json = MAPPER.writeValueAsString(list);
+        MethodWrapperBeanList result = MAPPER.readValue(json, MethodWrapperBeanList.class);
         assertNotNull(result);
         assertEquals(3, result.size());
         MethodWrapperBean bean = result.get(0);
@@ -142,11 +143,10 @@ public void testSimpleListMethod() throws Exception
 
     public void testSimpleArrayField() throws Exception
     {
-        ObjectMapper mapper = new ObjectMapper();
         FieldWrapperBeanArray array = new FieldWrapperBeanArray(new
                 FieldWrapperBean[] { new FieldWrapperBean(new BooleanValue(true)) });
-        String json = mapper.writeValueAsString(array);
-        FieldWrapperBeanArray result = mapper.readValue(json, FieldWrapperBeanArray.class);
+        String json = MAPPER.writeValueAsString(array);
+        FieldWrapperBeanArray result = MAPPER.readValue(json, FieldWrapperBeanArray.class);
         assertNotNull(result);
         FieldWrapperBean[] beans = result.beans;
         assertEquals(1, beans.length);
@@ -157,11 +157,10 @@ public void testSimpleArrayField() throws Exception
 
     public void testSimpleArrayMethod() throws Exception
     {
-        ObjectMapper mapper = new ObjectMapper();
         MethodWrapperBeanArray array = new MethodWrapperBeanArray(new
                 MethodWrapperBean[] { new MethodWrapperBean(new StringWrapper("A")) });
-        String json = mapper.writeValueAsString(array);
-        MethodWrapperBeanArray result = mapper.readValue(json, MethodWrapperBeanArray.class);
+        String json = MAPPER.writeValueAsString(array);
+        MethodWrapperBeanArray result = MAPPER.readValue(json, MethodWrapperBeanArray.class);
         assertNotNull(result);
         MethodWrapperBean[] beans = result.beans;
         assertEquals(1, beans.length);
@@ -172,11 +171,10 @@ public void testSimpleArrayMethod() throws Exception
     
     public void testSimpleMapField() throws Exception
     {
-        ObjectMapper mapper = new ObjectMapper();
         FieldWrapperBeanMap map = new FieldWrapperBeanMap();
         map.put("foop", new FieldWrapperBean(new IntWrapper(13)));
-        String json = mapper.writeValueAsString(map);
-        FieldWrapperBeanMap result = mapper.readValue(json, FieldWrapperBeanMap.class);
+        String json = MAPPER.writeValueAsString(map);
+        FieldWrapperBeanMap result = MAPPER.readValue(json, FieldWrapperBeanMap.class);
         assertNotNull(result);
         assertEquals(1, result.size());
         FieldWrapperBean bean = result.get("foop");
@@ -188,11 +186,10 @@ public void testSimpleMapField() throws Exception
 
     public void testSimpleMapMethod() throws Exception
     {
-        ObjectMapper mapper = new ObjectMapper();
         MethodWrapperBeanMap map = new MethodWrapperBeanMap();
         map.put("xyz", new MethodWrapperBean(new BooleanValue(true)));
-        String json = mapper.writeValueAsString(map);
-        MethodWrapperBeanMap result = mapper.readValue(json, MethodWrapperBeanMap.class);
+        String json = MAPPER.writeValueAsString(map);
+        MethodWrapperBeanMap result = MAPPER.readValue(json, MethodWrapperBeanMap.class);
         assertNotNull(result);
         assertEquals(1, result.size());
         MethodWrapperBean bean = result.get("xyz");
diff --git a/src/test/java/com/fasterxml/jackson/databind/jsontype/TestScalars.java b/src/test/java/com/fasterxml/jackson/databind/jsontype/TestScalars.java
@@ -8,6 +8,7 @@
 import com.fasterxml.jackson.annotation.JsonTypeInfo;
 import com.fasterxml.jackson.databind.BaseMapTest;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.testutil.NoCheckSubTypeValidator;
 
 public class TestScalars extends BaseMapTest
 {
@@ -49,7 +50,9 @@ public ScalarList add(Object v) {
     /**********************************************************************
      */
 
-    final ObjectMapper MAPPER = newJsonMapper();
+    final ObjectMapper MAPPER = jsonMapperBuilder()
+            .polymorphicTypeValidator(new NoCheckSubTypeValidator())
+            .build();
 
     /**
      * Ensure that per-property dynamic types work, both for "native" types
