Fix #1007: add more information on StreamReadConstraints violation exception msg

Author: cowtowncoder

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

@@ -224,8 +224,10 @@ public int getMaxStringLength() {
     public void validateNestingDepth(int depth) throws StreamConstraintsException
     {
         if (depth > _maxNestingDepth) {
-            throw new StreamConstraintsException(String.format("Depth (%d) exceeds the maximum allowed nesting depth (%d)",
-                    depth, _maxNestingDepth));
+            throw _constructException(
+                    "Document nesting depth (%d) exceeds the maximum allowed (%d, from %s)",
+                    depth, _maxNestingDepth,
+                    _constrainRef("getMaxNestingDepth"));
         }
     }
 
@@ -249,8 +251,10 @@ public void validateNestingDepth(int depth) throws StreamConstraintsException
     public void validateFPLength(int length) throws StreamConstraintsException
     {
         if (length > _maxNumLen) {
-            throw new StreamConstraintsException(String.format("Number length (%d) exceeds the maximum length (%d)",
-                    length, _maxNumLen));
+            throw _constructException(
+                    "Number value length (%d) exceeds the maximum allowed (%d, from %s)",
+                    length, _maxNumLen,
+                    _constrainRef("getMaxNumberLength"));
         }
     }
 
@@ -268,8 +272,10 @@ public void validateFPLength(int length) throws StreamConstraintsException
     public void validateIntegerLength(int length) throws StreamConstraintsException
     {
         if (length > _maxNumLen) {
-            throw new StreamConstraintsException(String.format("Number length (%d) exceeds the maximum length (%d)",
-                    length, _maxNumLen));
+            throw _constructException(
+                    "Number value length (%d) exceeds the maximum allowed (%d, from %s)",
+                    length, _maxNumLen,
+                    _constrainRef("getMaxNumberLength"));
         }
     }
 
@@ -287,8 +293,10 @@ public void validateIntegerLength(int length) throws StreamConstraintsException
     public void validateStringLength(int length) throws StreamConstraintsException
     {
         if (length > _maxStringLen) {
-            throw new StreamConstraintsException(String.format("String length (%d) exceeds the maximum length (%d)",
-                    length, _maxStringLen));
+            throw _constructException(
+                    "String value length (%d) exceeds the maximum allowed (%d, from %s)",
+                    length, _maxStringLen,
+                    _constrainRef("getMaxStringLength"));
         }
     }
 
@@ -315,9 +323,23 @@ public void validateBigIntegerScale(int scale) throws StreamConstraintsException
         final int limit = MAX_BIGINT_SCALE_MAGNITUDE;
 
         if (absScale > limit) {
-            throw new StreamConstraintsException(String.format(
-                    "BigDecimal scale (%d) magnitude exceeds maximum allowed (%d)",
-                    scale, limit));
+            throw _constructException(
+                    "BigDecimal scale (%d) magnitude exceeds the maximum allowed (%d)",
+                    scale, limit);
         }
     }
+
+    /*
+    /**********************************************************************
+    /* Error reporting
+    /**********************************************************************
+     */
+
+    protected StreamConstraintsException _constructException(String msgTemplate, Object... args) throws StreamConstraintsException {
+        throw new StreamConstraintsException(String.format(msgTemplate, args));
+    }
+
+    protected String _constrainRef(String method) {
+        return "`StreamReadConstraints."+method+"()`";
+    }
 }

src/test/java/com/fasterxml/jackson/core/constraints/DeeplyNestedContentReadTest.java

@@ -32,8 +32,8 @@ private void _testDeepNesting(JsonParser p) throws Exception
             while (p.nextToken() != null) { }
             fail("expected StreamConstraintsException");
         } catch (StreamConstraintsException e) {
-            assertEquals("Depth ("+(MAX_NESTING+1)
-                    +") exceeds the maximum allowed nesting depth ("+MAX_NESTING+")", e.getMessage());
+            assertEquals("Document nesting depth (1001) exceeds the maximum allowed (1000, from `StreamReadConstraints.getMaxNestingDepth()`)",
+                    e.getMessage());
         }
     }
 
@@ -58,8 +58,8 @@ private void _testLegacyConstraintSettingTest(JsonParser p, int maxNesting) thro
             while (p.nextToken() != null) { }
             fail("expected StreamConstraintsException");
         } catch (StreamConstraintsException e) {
-            assertEquals("Depth ("+(maxNesting+1)
-                    +") exceeds the maximum allowed nesting depth ("+maxNesting+")", e.getMessage());
+            assertEquals("Document nesting depth (41) exceeds the maximum allowed (40, from `StreamReadConstraints.getMaxNestingDepth()`)",
+                    e.getMessage());
         }
     }
 

src/test/java/com/fasterxml/jackson/core/constraints/LargeNumberReadTest.java

@@ -34,13 +34,13 @@ public void testBigBigDecimalsBytes() throws Exception
             _testBigBigDecimals(MODE_INPUT_STREAM, false);
             fail("Should not pass");
         } catch (StreamConstraintsException e) {
-            verifyException(e, "Invalid numeric value ", "exceeds the maximum length");
+            verifyException(e, "Invalid numeric value ", "exceeds the maximum");
         }
         try {
             _testBigBigDecimals(MODE_INPUT_STREAM_THROTTLED, false);
             fail("Should not pass");
         } catch (StreamConstraintsException jpe) {
-            verifyException(jpe, "Invalid numeric value ", "exceeds the maximum length");
+            verifyException(jpe, "Invalid numeric value ", "exceeds the maximum");
         }
     }
 
@@ -50,7 +50,7 @@ public void testBigBigDecimalsCharsFailByDefault() throws Exception
             _testBigBigDecimals(MODE_READER, false);
             fail("Should not pass");
         } catch (StreamConstraintsException jpe) {
-            verifyException(jpe, "Invalid numeric value ", "exceeds the maximum length");
+            verifyException(jpe, "Invalid numeric value ", "exceeds the maximum");
         }
     }
 
@@ -65,7 +65,7 @@ public void testBigBigDecimalsDataInputFailByDefault() throws Exception
             _testBigBigDecimals(MODE_DATA_INPUT, false);
             fail("Should not pass");
         } catch (StreamConstraintsException jpe) {
-            verifyException(jpe, "Invalid numeric value ", "exceeds the maximum length");
+            verifyException(jpe, "Invalid numeric value ", "exceeds the maximum allowed");
         }
     }