Add release notes wrt #762, minor cleanup

Author: cowtowncoder

release-notes/CREDITS-2.x

@@ -303,3 +303,7 @@ Illia Ovchynnikov (wingsofovnia@github)
   * Reported #759: JsonGenerator to provide current value to the context before
    starting objects
   (2.14.0)
+
+Evan Galpin (egalpin@github)
+  * Contributed #762: Make `JsonPointer` `java.io.Serializable`
+  (2.14.0)

release-notes/VERSION-2.x

@@ -32,6 +32,8 @@ JSON library.
  (contributed by @pjfanning)
 #759: JsonGenerator to provide current value to the context before starting objects
  (reported by Illia O)
+#762: Make `JsonPointer` `java.io.Serializable`
+ (contributed by Evan G)
 #763: `JsonFactory.createParser()` with `File` may leak `InputStream`s
 #764: `JsonFactory.createGenerator()` with `File` may leak `OutputStream`s
 

src/main/java/com/fasterxml/jackson/core/JsonPointer.java

@@ -26,6 +26,7 @@
 public class JsonPointer implements Serializable
 {
     private static final long serialVersionUID = 1L; 
+
     /**
      * Character used to separate segments.
      *
@@ -524,7 +525,7 @@ public JsonPointer head() {
         if (!(o instanceof JsonPointer)) return false;
         return _asString.equals(((JsonPointer) o)._asString);
     }
-    
+
     /*
     /**********************************************************
     /* Internal methods
@@ -651,21 +652,30 @@ private static void _appendEscape(StringBuilder sb, char c) {
         sb.append(c);
     }
 
+    /*
+    /**********************************************************
+    /* Support for JDK serialization (2.14+)
+    /**********************************************************
+     */
+
+    // Since 2.14: needed for efficient JDK serializability
     private Object writeReplace() {
-        return new SerializableJsonPointer(_asString);
+        return new Serialization(_asString);
     }
 
     /**
      * This must only exist to allow both final properties and implementation of
      * Externalizable/Serializable for JsonPointer
+     *
+     * @since 2.14
      */
-    private static class SerializableJsonPointer implements Externalizable {
+    static class Serialization implements Externalizable
+    {
         private String _asString;
 
-        public SerializableJsonPointer() {
-        }
+        public Serialization() { }
 
-        public SerializableJsonPointer(String asString) {
+        Serialization(String asString) {
             _asString = asString;
         }
 
@@ -678,7 +688,9 @@ public void writeExternal(ObjectOutput out) throws IOException {
         public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
             _asString = in.readUTF();
         }
+
         private Object readResolve() throws ObjectStreamException {
+            // NOTE: method handles canonicalization of "empty":
             return compile(_asString);
         }
     }

src/test/java/com/fasterxml/jackson/core/TestJDKSerializability.java

@@ -10,6 +10,12 @@
  */
 public class TestJDKSerializability extends BaseTest
 {
+    /*
+    /**********************************************************************
+    /* Main factory type(s)
+    /**********************************************************************
+     */
+
     public void testJsonFactorySerializable() throws Exception
     {
         JsonFactory f = new JsonFactory();
@@ -26,6 +32,12 @@ public void testJsonFactorySerializable() throws Exception
         assertEquals(origJson, _copyJson(f2, origJson, true));
     }
 
+    /*
+    /**********************************************************************
+    /* Parser-related types
+    /**********************************************************************
+     */
+
     public void testBase64Variant() throws Exception
     {
         {
@@ -92,6 +104,12 @@ public void testSourceReference() throws Exception
         assertSame(ref2, ContentReference.unknown());
     }
 
+    /*
+    /**********************************************************************
+    /* Exception types
+    /**********************************************************************
+     */
+
     public void testParseException() throws Exception
     {
         JsonFactory jf = new JsonFactory();
@@ -127,7 +145,34 @@ public void testGenerationException() throws Exception
         JsonGenerationException result = jdkDeserialize(stuff);
         assertNotNull(result);
     }
-    
+
+    /*
+    /**********************************************************************
+    /* Misc other types
+    /**********************************************************************
+     */
+
+    public void testPointerSerializationNonEmpty() throws Exception
+    {
+        // First, see that we can write and read a general JsonPointer
+        final String INPUT = "/Image/15/name";
+        JsonPointer original = JsonPointer.compile(INPUT);
+        byte[] ser = jdkSerialize(original);
+        JsonPointer copy = jdkDeserialize(ser);
+        assertNotSame(copy, original);
+        assertEquals(original, copy);
+    }
+
+    public void testPointerSerializationEmpty() throws Exception
+    {
+        // and then verify that "empty" instance gets canonicalized
+        final JsonPointer emptyP = JsonPointer.empty();
+        byte[] ser = jdkSerialize(emptyP);
+        JsonPointer result = jdkDeserialize(ser);
+        assertSame("Should get same 'empty' instance when JDK serialize+deserialize",
+                emptyP, result);
+    }
+
     /*
     /**********************************************************
     /* Helper methods

src/test/java/com/fasterxml/jackson/core/TestJsonPointer.java

@@ -1,12 +1,5 @@
 package com.fasterxml.jackson.core;
 
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.ObjectInputStream;
-import java.io.ObjectOutputStream;
-import java.io.Serializable;
-
 public class TestJsonPointer extends BaseTest
 {
     public void testSimplePath() throws Exception
@@ -235,32 +228,4 @@ public void testLongNumbers() throws Exception
         assertTrue(ptr.matches());
         assertNull(ptr.tail());
     }
-
-    private static <T extends Serializable> byte[] pickle(T obj)
-        throws IOException
-    {
-        ByteArrayOutputStream baos = new ByteArrayOutputStream();
-        ObjectOutputStream oos = new ObjectOutputStream(baos);
-        oos.writeObject(obj);
-        oos.close();
-        return baos.toByteArray();
-    }
-
-    private static <T extends Serializable> T unpickle(byte[] b, Class<T> cl)
-        throws IOException, ClassNotFoundException
-    {
-        ByteArrayInputStream bais = new ByteArrayInputStream(b);
-        ObjectInputStream ois = new ObjectInputStream(bais);
-        Object o = ois.readObject();
-        return cl.cast(o);
-    }
-    public void testPointerSerialization() throws Exception {
-
-        final String INPUT = "/Image/15/name";
-        JsonPointer original = JsonPointer.compile(INPUT);
-        JsonPointer copy = unpickle(pickle(original), JsonPointer.class);
-        assertNotSame(copy, original);
-        assertEquals(original, copy);
-
-    }
 }