Add feature to inverse read/write access logic

Author: ggrebert

src/main/java/com/fasterxml/jackson/databind/MapperFeature.java

@@ -1,5 +1,6 @@
 package com.fasterxml.jackson.databind;
 
+import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.databind.annotation.JsonSerialize;
 import com.fasterxml.jackson.databind.cfg.ConfigFeature;
 
@@ -280,6 +281,14 @@ public enum MapperFeature implements ConfigFeature
      */
     OVERRIDE_PUBLIC_ACCESS_MODIFIERS(true),
 
+    /**
+     * Feature that inverse logic in {@link JsonProperty#access}
+     * for <code>READ_ONLY</code> and <code>WRITE_ONLY</code>.
+     *<p>
+     * Feature is disabled by default.
+     */
+    INVERSE_READ_WRITE_ACCESS(false),
+
     /*
     /******************************************************
     /* Type-handling features

src/main/java/com/fasterxml/jackson/databind/introspect/POJOPropertyBuilder.java

@@ -946,6 +946,20 @@ public JsonProperty.Access removeNonVisible(boolean inferMutators,
         if (acc == null) {
             acc = JsonProperty.Access.AUTO;
         }
+
+        // [databind#2951] add feature to inverse access logic
+        if (_config.isEnabled(MapperFeature.INVERSE_READ_WRITE_ACCESS)) {
+            switch (acc) {
+            case READ_ONLY:
+                acc = JsonProperty.Access.WRITE_ONLY;
+                break;
+            case WRITE_ONLY:
+                acc = JsonProperty.Access.READ_ONLY;
+                break;
+            default:
+            }
+        }
+
         switch (acc) {
         case READ_ONLY:
             // [databind#2719]: Need to add ignorals, first, keeping in mind

src/test/java/com/fasterxml/jackson/databind/deser/filter/ReadOrWriteOnlyTest.java

@@ -11,6 +11,7 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 
 import com.fasterxml.jackson.databind.*;
+import com.fasterxml.jackson.databind.json.JsonMapper;
 
 import static org.junit.jupiter.api.Assertions.*;
 
@@ -35,6 +36,15 @@ public int getY() {
         }
     }
 
+    // for [databind#2951], add feature to inverse access logic
+    static class ReadAWriteB {
+        @JsonProperty(access=JsonProperty.Access.READ_ONLY)
+        public int a = 1;
+
+        @JsonProperty(access=JsonProperty.Access.WRITE_ONLY)
+        public int b = 2;
+    }
+
     public static class Pojo935
     {
         private String firstName = "Foo";
@@ -151,6 +161,22 @@ public void testReadOnlyAndWriteOnly() throws Exception
         assertEquals(6, result.y);
     }
 
+    // [databind#2951] add feature to inverse access logic
+    @Test
+    public void testInverseReadOnlyAndWriteOnly() throws Exception {
+        ObjectMapper mapper = JsonMapper.builder()
+                .enable(MapperFeature.INVERSE_READ_WRITE_ACCESS)
+                .build();
+
+        String json = mapper.writeValueAsString(new ReadAWriteB());
+        assertEquals("{\"b\":2}", json);
+
+        ReadAWriteB result = mapper.readValue("{\"a\":5, \"b\":6}", ReadAWriteB.class);
+        assertNotNull(result);
+        assertEquals(5, result.a);
+        assertEquals(2, result.b);
+    }
+
     @Test
     public void testReadOnly935() throws Exception
     {