Implement #1564: Add SimpleStreamReadContext.rollbackValueRead() method (#1565)

Author: cowtowncoder

release-notes/VERSION

@@ -22,6 +22,7 @@ JSON library.
 #1544: Validate `read()` parameters in `MergedStream` and `UTF32Reader`
  (implemented by @pjfanning)
 #1545: Increase Android baseline from 26 to 34 in Jackson 3.2
+#1564: Add `SimpleStreamReadContext.rollbackValueRead()` method
 
 3.1.1 (not yet released)
 

src/main/java/tools/jackson/core/util/SimpleStreamReadContext.java

@@ -64,21 +64,6 @@ public SimpleStreamReadContext(int type, SimpleStreamReadContext parent, int nes
         _index = -1;
     }
 
-    // REMOVE as soon as nothing uses this
-    @Deprecated
-    public SimpleStreamReadContext(int type, SimpleStreamReadContext parent,
-            DupDetector dups,
-            int lineNr, int colNr) {
-        super();
-        _parent = parent;
-        _dups = dups;
-        _type = type;
-        _lineNr = lineNr;
-        _columnNr = colNr;
-        _index = -1;
-        _nestingDepth = -1;
-    }
-
     protected void reset(int type, int lineNr, int colNr) {
         _type = type;
         _currentValue = null;
@@ -205,6 +190,21 @@ public int valueRead() {
         return ++_index; // starts from -1
     }
 
+    /**
+     * Method to call to "undo" previous call to {@link #valueRead()}; will
+     * decrement {@code _index} unless it is already negative.
+     *
+     * @return Index after rollback
+     *
+     * @since 3.2
+     */
+    public int rollbackValueRead() {
+        if (_index >= 0) {
+            --_index;
+        }
+        return _index;
+    }
+
     /**
      * Method called to indicate what the "current" name (Object property name
      * just decoded) is: may also trigger duplicate detection.

src/main/java/tools/jackson/core/util/SimpleStreamWriteContext.java

@@ -68,20 +68,6 @@ protected SimpleStreamWriteContext(int type, SimpleStreamWriteContext parent, in
         _currentValue = currentValue;
     }
 
-    // REMOVE as soon as nothing uses this
-    /*
-    @Deprecated
-    protected SimpleStreamWriteContext(int type, SimpleStreamWriteContext parent,
-            DupDetector dups, Object currentValue) {
-        super();
-        _type = type;
-        _parent = parent;
-        _dups = dups;
-        _index = -1;
-        _currentValue = currentValue;
-    }
-    */
-
     private SimpleStreamWriteContext reset(int type, Object currentValue) {
         _type = type;
         // Due to way reuse works, "_parent" and "_nestingDepth" are fine already
@@ -204,7 +190,7 @@ public boolean writeName(String name) throws StreamWriteException {
     private final void _checkDup(DupDetector dd, String name) throws StreamWriteException {
         if (dd.isDup(name)) {
             Object src = dd.getSource();
-            throw new StreamWriteException(((src instanceof JsonGenerator) ? ((JsonGenerator) src) : null),
+            throw new StreamWriteException(((src instanceof JsonGenerator jg) ? jg : null),
                     "Duplicate Object property \""+name+"\"");
         }
     }

src/test/java/tools/jackson/core/unittest/util/SimpleStreamReadContextTest.java

@@ -244,24 +244,6 @@ void nestedContexts()
         assertSame(object, innerArray.getParent());
     }
 
-    @Test
-    void deprecatedConstructor()
-    {
-        // Test the deprecated constructor without nestingDepth parameter
-        @SuppressWarnings("deprecation")
-        SimpleStreamReadContext ctx = new SimpleStreamReadContext(
-                SimpleStreamReadContext.TYPE_OBJECT,
-                null,
-                null,
-                1,
-                0
-        );
-
-        assertTrue(ctx.inObject());
-        assertNull(ctx.getParent());
-        assertEquals(-1, ctx.getNestingDepth()); // Should be -1 when using deprecated constructor
-    }
-
     @Test
     void contextTypeDescriptions()
     {