Fix #2176

Author: cowtowncoder

release-notes/VERSION

@@ -35,5 +35,6 @@ Versions: 3.x (for earlier see VERSION-2.x)
 #1994: Limit size of `SerializerCache`, auto-flush on exceeding
 #1995: Limit size of `DeserializerCache`, auto-flush on exceeding
 #2040: Remove `JsonSerializer.isEmpty()` from 3.0
+#2176: Add `JsonMapper.shared()` static method
 - Remove `MappingJsonFactory`
 - Add context parameter for `TypeSerializer` contextualization (`forProperty()`)

src/main/java/com/fasterxml/jackson/databind/json/JsonMapper.java

@@ -113,9 +113,9 @@ protected Object readResolve() {
     }
 
     /*
-    /**********************************************************
+    /**********************************************************************
     /* Life-cycle, constructors
-    /**********************************************************
+    /**********************************************************************
      */
 
     public JsonMapper() {
@@ -131,9 +131,9 @@ public JsonMapper(Builder b) {
     }
 
     /*
-    /**********************************************************
+    /**********************************************************************
     /* Life-cycle, builders
-    /**********************************************************
+    /**********************************************************************
      */
 
     public static JsonMapper.Builder builder() {
@@ -151,9 +151,25 @@ public JsonMapper.Builder rebuild() {
     }
 
     /*
-    /**********************************************************
+    /**********************************************************************
+    /* Life-cycle, shared "vanilla" (default configuration) instance
+    /**********************************************************************
+     */
+
+    /**
+     * Accessor method for getting globally shared "default" {@link JsonMapper}
+     * instance: one that has default configuration, no modules registered, no
+     * config overrides. Usable mostly when dealing "untyped" or Tree-style
+     * content reading and writing.
+     */
+    public static JsonMapper shared() {
+        return SharedWrapper.wrapped();
+    }
+
+    /*
+    /**********************************************************************
     /* Standard method overrides
-    /**********************************************************
+    /**********************************************************************
      */
 
     @Override
@@ -179,4 +195,20 @@ public boolean isEnabled(JsonReadFeature f) {
     public boolean isEnabled(JsonWriteFeature f) {
         return _serializationConfig.hasFormatFeature(f);
     }
+
+    /*
+    /**********************************************************
+    /* Helper class(es)
+    /**********************************************************
+     */
+
+    /**
+     * Helper class to contain dynamically constructed "shared" instance of
+     * mapper, should one be needed via {@link #shared}.
+     */
+    private final static class SharedWrapper {
+        private final static JsonMapper MAPPER = JsonMapper.builder().build();
+
+        public static JsonMapper wrapped() { return MAPPER; }
+    }
 }

src/main/java/com/fasterxml/jackson/databind/node/BaseJsonNode.java

@@ -6,6 +6,7 @@
 import com.fasterxml.jackson.databind.JsonNode;
 import com.fasterxml.jackson.databind.JsonSerializable;
 import com.fasterxml.jackson.databind.SerializerProvider;
+import com.fasterxml.jackson.databind.json.JsonMapper;
 import com.fasterxml.jackson.databind.jsontype.TypeSerializer;
 
 /**
@@ -111,11 +112,21 @@ public abstract void serializeWithType(JsonGenerator jgen, SerializerProvider pr
 
    @Override
    public String toString() {
-       return InternalNodeMapper.nodeToString(this);
+       try {
+           return JsonMapper.shared().writeValueAsString(this);
+       } catch (IOException e) { // should never occur
+           throw new RuntimeException(e);
+       }
    }
 
    @Override
    public String toPrettyString() {
-       return InternalNodeMapper.nodeToPrettyString(this);
+       try {
+           return JsonMapper.shared()
+                   .writerWithDefaultPrettyPrinter()
+                   .writeValueAsString(this);
+       } catch (IOException e) { // should never occur
+           throw new RuntimeException(e);
+       }
    }
 }