Add an alternative creator for collections

1 files changed, 46 insertions, 21 deletions

diff --git a/src/main/java/com/fasterxml/jackson/databind/deser/ValueInstantiator.java b/src/main/java/com/fasterxml/jackson/databind/deser/ValueInstantiator.java
index 03303e6a7..c0eadd01d 100644
--- a/src/main/java/com/fasterxml/jackson/databind/deser/ValueInstantiator.java
+++ b/src/main/java/com/fasterxml/jackson/databind/deser/ValueInstantiator.java
@@ -3,7 +3,6 @@ package com.fasterxml.jackson.databind.deser;
 import java.io.IOException;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
-
 import com.fasterxml.jackson.databind.*;
 import com.fasterxml.jackson.databind.introspect.AnnotatedParameter;
 import com.fasterxml.jackson.databind.introspect.AnnotatedWithParams;
@@ -143,8 +142,7 @@ public abstract class ValueInstantiator
      * This method is called if {@link #getFromObjectArguments} returns
      * null or empty List.
      */
-    public Object createUsingDefault(DeserializationContext ctxt)
-        throws IOException, JsonProcessingException {
+    public Object createUsingDefault(DeserializationContext ctxt) throws IOException {
         throw new JsonMappingException("Can not instantiate value of type "
                 +getValueTypeDesc()+"; no default creator found");
     }
@@ -157,8 +155,7 @@ public abstract class ValueInstantiator
      * This method is called if {@link #getFromObjectArguments} returns
      * a non-empty List of arguments.
      */
-    public Object createFromObjectWith(DeserializationContext ctxt, Object[] args)
-        throws IOException, JsonProcessingException {
+    public Object createFromObjectWith(DeserializationContext ctxt, Object[] args) throws IOException {
         throw new JsonMappingException("Can not instantiate value of type "+getValueTypeDesc()+" with arguments");
     }
 
@@ -166,8 +163,7 @@ public abstract class ValueInstantiator
      * Method to called to create value instance from JSON Object using
      * an intermediate "delegate" value to pass to createor method
      */
-    public Object createUsingDelegate(DeserializationContext ctxt, Object delegate)
-        throws IOException, JsonProcessingException {
+    public Object createUsingDelegate(DeserializationContext ctxt, Object delegate) throws IOException {
         throw new JsonMappingException("Can not instantiate value of type "+getValueTypeDesc()+" using delegate");
     }
     
@@ -178,32 +174,26 @@ public abstract class ValueInstantiator
     /**********************************************************
      */
     
-    public Object createFromString(DeserializationContext ctxt, String value)
-            throws IOException, JsonProcessingException {
-        throw new JsonMappingException("Can not instantiate value of type "
-                +getValueTypeDesc()+" from String value '"+value+"'");
+    public Object createFromString(DeserializationContext ctxt, String value) throws IOException {
+        return _createFromStringFallbacks(ctxt, value);
     }
-    
-    public Object createFromInt(DeserializationContext ctxt, int value)
-            throws IOException, JsonProcessingException {
+
+    public Object createFromInt(DeserializationContext ctxt, int value) throws IOException {
         throw new JsonMappingException("Can not instantiate value of type "
                 +getValueTypeDesc()+" from Integer number ("+value+", int)");
     }
 
-    public Object createFromLong(DeserializationContext ctxt, long value)
-            throws IOException, JsonProcessingException {
+    public Object createFromLong(DeserializationContext ctxt, long value) throws IOException {
         throw new JsonMappingException("Can not instantiate value of type "
                 +getValueTypeDesc()+" from Integer number ("+value+", long)");
     }
 
-    public Object createFromDouble(DeserializationContext ctxt, double value)
-            throws IOException, JsonProcessingException {
+    public Object createFromDouble(DeserializationContext ctxt, double value) throws IOException {
         throw new JsonMappingException("Can not instantiate value of type "
                 +getValueTypeDesc()+" from Floating-point number ("+value+", double)");
     }
     
-    public Object createFromBoolean(DeserializationContext ctxt, boolean value)
-            throws IOException, JsonProcessingException {
+    public Object createFromBoolean(DeserializationContext ctxt, boolean value) throws IOException {
         throw new JsonMappingException("Can not instantiate value of type "
                 +getValueTypeDesc()+" from Boolean value ("+value+")");
     }
@@ -225,7 +215,7 @@ public abstract class ValueInstantiator
      * this method may return null .
      */
     public AnnotatedWithParams getDefaultCreator() { return null; }
-    
+
     /**
      * Method that can be called to try to access member (constructor,
      * static factory method) that is used as the "delegate creator".
@@ -252,4 +242,39 @@ public abstract class ValueInstantiator
      * needs further annotation to help make the creator complete.
      */
     public AnnotatedParameter getIncompleteParameter() { return null; }
+
+    /*
+    /**********************************************************
+    /* Helper methods
+    /**********************************************************
+     */
+
+    /**
+     * @since 2.4 (demoted from <code>StdValueInstantiator)
+     */
+    protected Object _createFromStringFallbacks(DeserializationContext ctxt, String value)
+            throws IOException, JsonProcessingException
+    {
+        /* 28-Sep-2011, tatu: Ok this is not clean at all; but since there are legacy
+         *   systems that expect conversions in some cases, let's just add a minimal
+         *   patch (note: same could conceivably be used for numbers too).
+         */
+        if (canCreateFromBoolean()) {
+            String str = value.trim();
+            if ("true".equals(str)) {
+                return createFromBoolean(ctxt, true);
+            }
+            if ("false".equals(str)) {
+                return createFromBoolean(ctxt, false);
+            }
+        }
+        // also, empty Strings might be accepted as null Object...
+        if (value.length() == 0) {
+            if (ctxt.isEnabled(DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT)) {
+                return null;
+            }
+        }
+        throw new JsonMappingException("Can not instantiate value of type "+getValueTypeDesc()
+                +" from String value ('"+value+"'); no single-String constructor/factory method");
+    }
 }