Refactoring to (eventually) allow XmlMapper override wrapped-root handling

3 files changed, 81 insertions, 150 deletions

diff --git a/src/main/java/com/fasterxml/jackson/databind/ObjectMapper.java b/src/main/java/com/fasterxml/jackson/databind/ObjectMapper.java
index 899149f69..ab273ffc1 100644
--- a/src/main/java/com/fasterxml/jackson/databind/ObjectMapper.java
+++ b/src/main/java/com/fasterxml/jackson/databind/ObjectMapper.java
@@ -4497,13 +4497,7 @@ public class ObjectMapper
         } else if (t == JsonToken.END_ARRAY || t == JsonToken.END_OBJECT) {
             result = null;
         } else { // pointing to event other than null
-            JsonDeserializer<Object> deser = _findRootDeserializer(ctxt, valueType);
-            // ok, let's get the value
-            if (cfg.useRootWrapping()) {
-                result = _unwrapAndDeserialize(p, ctxt, cfg, valueType, deser);
-            } else {
-                result = deser.deserialize(p, ctxt);
-            }
+            result = ctxt.readRootValue(p, valueType, _findRootDeserializer(ctxt, valueType), null);
         }
         // Need to consume the token too
         p.clearCurrentToken();
@@ -4527,12 +4521,8 @@ public class ObjectMapper
             } else if (t == JsonToken.END_ARRAY || t == JsonToken.END_OBJECT) {
                 result = null;
             } else {
-                JsonDeserializer<Object> deser = _findRootDeserializer(ctxt, valueType);
-                if (cfg.useRootWrapping()) {
-                    result = _unwrapAndDeserialize(p, ctxt, cfg, valueType, deser);
-                } else {
-                    result = deser.deserialize(p, ctxt);
-                }
+                result = ctxt.readRootValue(p, valueType,
+                        _findRootDeserializer(ctxt, valueType), null);
                 ctxt.checkUnresolvedObjectId();
             }
             if (cfg.isEnabled(DeserializationFeature.FAIL_ON_TRAILING_TOKENS)) {
@@ -4573,57 +4563,19 @@ public class ObjectMapper
             if (t == JsonToken.VALUE_NULL) {
                 resultNode = cfg.getNodeFactory().nullNode();
             } else {
-                JsonDeserializer<Object> deser = _findRootDeserializer(ctxt, valueType);
-                if (cfg.useRootWrapping()) {
-                    resultNode = (JsonNode) _unwrapAndDeserialize(p, ctxt, cfg, valueType, deser);
-                } else {
-                    resultNode = (JsonNode) deser.deserialize(p, ctxt);
-                }
+                resultNode = (JsonNode) ctxt.readRootValue(p, valueType,
+                        _findRootDeserializer(ctxt, valueType), null);
+                // No ObjectIds so can ignore
+//              ctxt.checkUnresolvedObjectId();
             }
             if (cfg.isEnabled(DeserializationFeature.FAIL_ON_TRAILING_TOKENS)) {
                 _verifyNoTrailingTokens(p, ctxt, valueType);
             }
-            // No ObjectIds so can ignore
-//            ctxt.checkUnresolvedObjectId();
             return resultNode;
         }
     }
 
-    protected Object _unwrapAndDeserialize(JsonParser p, DeserializationContext ctxt, 
-            DeserializationConfig config,
-            JavaType rootType, JsonDeserializer<Object> deser)
-        throws IOException
-    {
-        PropertyName expRootName = config.findRootName(rootType);
-        // 12-Jun-2015, tatu: Should try to support namespaces etc but...
-        String expSimpleName = expRootName.getSimpleName();
-        if (p.currentToken() != JsonToken.START_OBJECT) {
-            ctxt.reportWrongTokenException(rootType, JsonToken.START_OBJECT,
-                    "Current token not START_OBJECT (needed to unwrap root name '%s'), but %s",
-                    expSimpleName, p.currentToken());
-        }
-        if (p.nextToken() != JsonToken.FIELD_NAME) {
-            ctxt.reportWrongTokenException(rootType, JsonToken.FIELD_NAME,
-                    "Current token not FIELD_NAME (to contain expected root name '%s'), but %s",
-                    expSimpleName, p.currentToken());
-        }
-        String actualName = p.getCurrentName();
-        if (!expSimpleName.equals(actualName)) {
-            ctxt.reportPropertyInputMismatch(rootType, actualName,
-                    "Root name '%s' does not match expected ('%s') for type %s",
-                    actualName, expSimpleName, rootType);
-        }
-        // ok, then move to value itself....
-        p.nextToken();
-        Object result = deser.deserialize(p, ctxt);
-        // and last, verify that we now get matching END_OBJECT
-        if (p.nextToken() != JsonToken.END_OBJECT) {
-            ctxt.reportWrongTokenException(rootType, JsonToken.END_OBJECT,
-                    "Current token not END_OBJECT (to match wrapper object with root name '%s'), but %s",
-                    expSimpleName, p.currentToken());
-        }
-        return result;
-    }
+
 
     /**
      * Internal helper method called to create an instance of {@link DeserializationContext}
diff --git a/src/main/java/com/fasterxml/jackson/databind/ObjectReader.java b/src/main/java/com/fasterxml/jackson/databind/ObjectReader.java
index 17ca4d65a..313f39276 100644
--- a/src/main/java/com/fasterxml/jackson/databind/ObjectReader.java
+++ b/src/main/java/com/fasterxml/jackson/databind/ObjectReader.java
@@ -2011,18 +2011,7 @@ public class ObjectReader
         } else if (t == JsonToken.END_ARRAY || t == JsonToken.END_OBJECT) {
             result = valueToUpdate;
         } else { // pointing to event other than null
-            JsonDeserializer<Object> deser = _findRootDeserializer(ctxt);
-            if (_unwrapRoot) {
-                result = _unwrapAndDeserialize(p, ctxt, _valueType, deser);
-            } else {
-                if (valueToUpdate == null) {
-                    result = deser.deserialize(p, ctxt);
-                } else {
-                    // 20-Mar-2017, tatu: Important! May be different from `valueToUpdate`
-                    //   for immutable Objects like Java arrays; logical result
-                    result = deser.deserialize(p, ctxt, valueToUpdate);
-                }
-            }
+            result = ctxt.readRootValue(p, _valueType, _findRootDeserializer(ctxt), _valueToUpdate);
         }
         // Need to consume the token too
         p.clearCurrentToken();
@@ -2037,7 +2026,7 @@ public class ObjectReader
         try (JsonParser p = p0) {
             Object result;
 
-            DefaultDeserializationContext ctxt = createDeserializationContext(p);
+            final DefaultDeserializationContext ctxt = createDeserializationContext(p);
             JsonToken t = _initForReading(ctxt, p);
             if (t == JsonToken.VALUE_NULL) {
                 if (_valueToUpdate == null) {
@@ -2048,17 +2037,7 @@ public class ObjectReader
             } else if (t == JsonToken.END_ARRAY || t == JsonToken.END_OBJECT) {
                 result = _valueToUpdate;
             } else {
-                JsonDeserializer<Object> deser = _findRootDeserializer(ctxt);
-                if (_unwrapRoot) {
-                    result = _unwrapAndDeserialize(p, ctxt, _valueType, deser);
-                } else {
-                    if (_valueToUpdate == null) {
-                        result = deser.deserialize(p, ctxt);
-                    } else {
-                        deser.deserialize(p, ctxt, _valueToUpdate);
-                        result = _valueToUpdate;                    
-                    }
-                }
+                result = ctxt.readRootValue(p, _valueType, _findRootDeserializer(ctxt), _valueToUpdate);
             }
             if (_config.isEnabled(DeserializationFeature.FAIL_ON_TRAILING_TOKENS)) {
                 _verifyNoTrailingTokens(p, ctxt, _valueType);
@@ -2088,24 +2067,14 @@ public class ObjectReader
                 return _config.getNodeFactory().missingNode();
             }
         }
-        final DefaultDeserializationContext ctxt;
+        final DefaultDeserializationContext ctxt = createDeserializationContext(p);
         final JsonNode resultNode;
-        final boolean checkTrailing = _config.isEnabled(DeserializationFeature.FAIL_ON_TRAILING_TOKENS);
 
         if (t == JsonToken.VALUE_NULL) {
             resultNode = _config.getNodeFactory().nullNode();
-            if (!checkTrailing) {
-                return resultNode;
-            }
-            ctxt = createDeserializationContext(p);
         } else {
-            ctxt = createDeserializationContext(p);
-            final JsonDeserializer<Object> deser = _findTreeDeserializer(ctxt);
-            if (_unwrapRoot) {
-                resultNode = (JsonNode) _unwrapAndDeserialize(p, ctxt, _jsonNodeType(), deser);
-            } else {
-                resultNode = (JsonNode) deser.deserialize(p, ctxt);
-            }
+            // Will not be called for merge (need not pass _valueToUpdate)
+            resultNode = (JsonNode) ctxt.readRootValue(p, _jsonNodeType(), _findTreeDeserializer(ctxt), null);
         }
         if (_config.isEnabled(DeserializationFeature.FAIL_ON_TRAILING_TOKENS)) {
             _verifyNoTrailingTokens(p, ctxt, _jsonNodeType());
@@ -2130,25 +2099,15 @@ public class ObjectReader
                 return null;
             }
         }
-        final DefaultDeserializationContext ctxt;
+        final DefaultDeserializationContext ctxt = createDeserializationContext(p);
         final JsonNode resultNode;
-        final boolean checkTrailing = _config.isEnabled(DeserializationFeature.FAIL_ON_TRAILING_TOKENS);
         if (t == JsonToken.VALUE_NULL) {
             resultNode = _config.getNodeFactory().nullNode();
-            if (!checkTrailing) {
-                return resultNode;
-            }
-            ctxt = createDeserializationContext(p);
         } else {
-            ctxt = createDeserializationContext(p);
-            final JsonDeserializer<Object> deser = _findTreeDeserializer(ctxt);
-            if (_unwrapRoot) {
-                resultNode = (JsonNode) _unwrapAndDeserialize(p, ctxt, _jsonNodeType(), deser);
-            } else {
-                resultNode = (JsonNode) deser.deserialize(p, ctxt);
-            }
+            // Will not be called for merge (need not pass _valueToUpdate)
+            resultNode = (JsonNode) ctxt.readRootValue(p, _jsonNodeType(), _findTreeDeserializer(ctxt), null);
         }
-        if (checkTrailing) {
+        if (_config.isEnabled(DeserializationFeature.FAIL_ON_TRAILING_TOKENS)) {
             _verifyNoTrailingTokens(p, ctxt, _jsonNodeType());
         }
         return resultNode;
@@ -2165,47 +2124,6 @@ public class ObjectReader
         return _newIterator(p, ctxt, _findRootDeserializer(ctxt), true);
     }
 
-    protected Object _unwrapAndDeserialize(JsonParser p, DeserializationContext ctxt,
-            JavaType rootType, JsonDeserializer<Object> deser) throws IOException
-    {
-        PropertyName expRootName = _config.findRootName(rootType);
-        // 12-Jun-2015, tatu: Should try to support namespaces etc but...
-        String expSimpleName = expRootName.getSimpleName();
-
-        if (p.currentToken() != JsonToken.START_OBJECT) {
-            ctxt.reportWrongTokenException(rootType, JsonToken.START_OBJECT,
-                    "Current token not START_OBJECT (needed to unwrap root name '%s'), but %s",
-                    expSimpleName, p.currentToken());
-        }
-        if (p.nextToken() != JsonToken.FIELD_NAME) {
-            ctxt.reportWrongTokenException(rootType, JsonToken.FIELD_NAME,
-                    "Current token not FIELD_NAME (to contain expected root name '%s'), but %s", 
-                    expSimpleName, p.currentToken());
-        }
-        String actualName = p.getCurrentName();
-        if (!expSimpleName.equals(actualName)) {
-            ctxt.reportPropertyInputMismatch(rootType, actualName,
-                    "Root name '%s' does not match expected ('%s') for type %s",
-                    actualName, expSimpleName, rootType);
-        }
-        // ok, then move to value itself....
-        p.nextToken();
-        Object result;
-        if (_valueToUpdate == null) {
-            result = deser.deserialize(p, ctxt);
-        } else {
-            deser.deserialize(p, ctxt, _valueToUpdate);
-            result = _valueToUpdate;                    
-        }
-        // and last, verify that we now get matching END_OBJECT
-        if (p.nextToken() != JsonToken.END_OBJECT) {
-            ctxt.reportWrongTokenException(rootType, JsonToken.END_OBJECT,
-                    "Current token not END_OBJECT (to match wrapper object with root name '%s'), but %s",
-                    expSimpleName, p.currentToken());
-        }
-        return result;
-    }
-
     /**
      * Consider filter when creating JsonParser.  
      */
diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/DefaultDeserializationContext.java b/src/main/java/com/fasterxml/jackson/databind/deser/DefaultDeserializationContext.java
index 8a66c307d..cf43d1f56 100644
--- a/src/main/java/com/fasterxml/jackson/databind/deser/DefaultDeserializationContext.java
+++ b/src/main/java/com/fasterxml/jackson/databind/deser/DefaultDeserializationContext.java
@@ -1,5 +1,6 @@
 package com.fasterxml.jackson.databind.deser;
 
+import java.io.IOException;
 import java.util.*;
 import java.util.Map.Entry;
 
@@ -8,7 +9,7 @@ import com.fasterxml.jackson.annotation.ObjectIdResolver;
 import com.fasterxml.jackson.annotation.ObjectIdGenerator.IdKey;
 
 import com.fasterxml.jackson.core.JsonParser;
-
+import com.fasterxml.jackson.core.JsonToken;
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.databind.cfg.HandlerInstantiator;
 import com.fasterxml.jackson.databind.deser.impl.ReadableObjectId;
@@ -284,7 +285,7 @@ public abstract class DefaultDeserializationContext
 
     /*
     /**********************************************************
-    /* Extended API
+    /* Extended API, life-cycle
     /**********************************************************
      */
 
@@ -306,6 +307,66 @@ public abstract class DefaultDeserializationContext
     
     /*
     /**********************************************************
+    /* Extended API, read methods
+    /**********************************************************
+     */
+
+    public Object readRootValue(JsonParser p, JavaType valueType,
+            JsonDeserializer<Object> deser, Object valueToUpdate)
+        throws IOException
+    {
+        if (_config.useRootWrapping()) {
+            return _unwrapAndDeserialize(p, valueType, deser, valueToUpdate);
+        }
+        if (valueToUpdate == null) {
+            return deser.deserialize(p, this);
+        }
+        return deser.deserialize(p, this, valueToUpdate);
+    }
+
+    protected Object _unwrapAndDeserialize(JsonParser p,
+            JavaType rootType, JsonDeserializer<Object> deser,
+            Object valueToUpdate)
+        throws IOException
+    {
+        PropertyName expRootName = _config.findRootName(rootType);
+        // 12-Jun-2015, tatu: Should try to support namespaces etc but...
+        String expSimpleName = expRootName.getSimpleName();
+        if (p.currentToken() != JsonToken.START_OBJECT) {
+            reportWrongTokenException(rootType, JsonToken.START_OBJECT,
+                    "Current token not START_OBJECT (needed to unwrap root name '%s'), but %s",
+                    expSimpleName, p.currentToken());
+        }
+        if (p.nextToken() != JsonToken.FIELD_NAME) {
+            reportWrongTokenException(rootType, JsonToken.FIELD_NAME,
+                    "Current token not FIELD_NAME (to contain expected root name '%s'), but %s",
+                    expSimpleName, p.currentToken());
+        }
+        String actualName = p.getCurrentName();
+        if (!expSimpleName.equals(actualName)) {
+            reportPropertyInputMismatch(rootType, actualName,
+                    "Root name '%s' does not match expected ('%s') for type %s",
+                    actualName, expSimpleName, rootType);
+        }
+        // ok, then move to value itself....
+        p.nextToken();
+        final Object result;
+        if (valueToUpdate == null) {
+            result = deser.deserialize(p, this);
+        } else {
+            result = deser.deserialize(p, this, valueToUpdate);
+        }
+        // and last, verify that we now get matching END_OBJECT
+        if (p.nextToken() != JsonToken.END_OBJECT) {
+            reportWrongTokenException(rootType, JsonToken.END_OBJECT,
+                    "Current token not END_OBJECT (to match wrapper object with root name '%s'), but %s",
+                    expSimpleName, p.currentToken());
+        }
+        return result;
+    }
+
+    /*
+    /**********************************************************
     /* And then the concrete implementation class
     /**********************************************************
      */