Add fix for issue #357 - strick parsing of null, true and false keywords

json-iterator · abhisheks-gh · Jan 1, 2026 · Jan 1, 2026 · a658fee5a1f03189af738275abd37ced0edc1b5c
commit a658fee5a1f03189af738275abd37ced0edc1b5c
diff --git a/src/main/java/com/jsoniter/IterImpl.java b/src/main/java/com/jsoniter/IterImpl.java
@@ -183,13 +183,12 @@ public static Any readAny(JsonIterator iter) throws IOException {
                 skipString(iter);
                 return Any.lazyString(iter.buf, start, iter.head);
             case 't':
-                skipFixedBytes(iter, 3);
-                return Any.wrap(true);
             case 'f':
-                skipFixedBytes(iter, 4);
-                return Any.wrap(false);
+                iter.unreadByte();
+                return Any.wrap(iter.readBoolean());
             case 'n':
-                skipFixedBytes(iter, 3);
+                iter.unreadByte();
+                iter.readNull();
                 return Any.wrap((Object) null);
             case '[':
                 skipArray(iter);

diff --git a/src/main/java/com/jsoniter/IterImplForStreaming.java b/src/main/java/com/jsoniter/IterImplForStreaming.java
@@ -326,16 +326,12 @@ public static Any readAny(JsonIterator iter) throws IOException {
                 byte[] copied = copySkippedBytes(iter);
                 return Any.lazyString(copied, 0, copied.length);
             case 't':
-                skipFixedBytes(iter, 3);
-                iter.skipStartedAt = -1;
-                return Any.wrap(true);
             case 'f':
-                skipFixedBytes(iter, 4);
-                iter.skipStartedAt = -1;
-                return Any.wrap(false);
+                iter.unreadByte();
+                return Any.wrap(iter.readBoolean());
             case 'n':
-                skipFixedBytes(iter, 3);
-                iter.skipStartedAt = -1;
+                iter.unreadByte();
+                iter.readNull();
                 return Any.wrap((Object) null);
             case '[':
                 skipArray(iter);

diff --git a/src/main/java/com/jsoniter/IterImplObject.java b/src/main/java/com/jsoniter/IterImplObject.java
@@ -8,8 +8,10 @@ public static final String readObject(JsonIterator iter) throws IOException {
         byte c = IterImpl.nextToken(iter);
         switch (c) {
             case 'n':
-                IterImpl.skipFixedBytes(iter, 3);
-                return null;
+                iter.unreadByte();
+                if (iter.readNull()) {
+                    return null;
+                }
             case '{':
                 c = IterImpl.nextToken(iter);
                 if (c == '"') {

diff --git a/src/main/java/com/jsoniter/IterImplSkip.java b/src/main/java/com/jsoniter/IterImplSkip.java
@@ -35,12 +35,14 @@ public static final void skip(JsonIterator iter) throws IOException {
             case '9':
                 IterImpl.skipUntilBreak(iter);
                 return;
-            case 't':
             case 'n':
-                IterImpl.skipFixedBytes(iter, 3); // true or null
+                iter.unreadByte();
+                iter.readNull();
                 return;
+            case 't':
             case 'f':
-                IterImpl.skipFixedBytes(iter, 4); // false
+                iter.unreadByte();
+                iter.readBoolean(); // true or false
                 return;
             case '[':
                 IterImpl.skipArray(iter);

diff --git a/src/main/java/com/jsoniter/JsonIterator.java b/src/main/java/com/jsoniter/JsonIterator.java
@@ -163,21 +163,34 @@ public final boolean readNull() throws IOException {
             unreadByte();
             return false;
         }
-        IterImpl.skipFixedBytes(this, 3); // null
-        return true;
+        if (IterImpl.readByte(this) == 'u' &&
+            IterImpl.readByte(this) == 'l' &&
+            IterImpl.readByte(this) == 'l') {
+            return true; // null
+        }
+        throw reportError("readNull", "expect null");
     }
 
     public final boolean readBoolean() throws IOException {
         byte c = IterImpl.nextToken(this);
         if ('t' == c) {
-            IterImpl.skipFixedBytes(this, 3); // true
-            return true;
+            if (IterImpl.readByte(this) == 'r' &&
+                IterImpl.readByte(this) == 'u' &&
+                IterImpl.readByte(this) == 'e') {
+                return true;
+            }
+            throw reportError("readBoolean", "expect true");
         }
         if ('f' == c) {
-            IterImpl.skipFixedBytes(this, 4); // false
-            return false;
+            if (IterImpl.readByte(this) == 'a' &&
+                IterImpl.readByte(this) == 'l' &&
+                IterImpl.readByte(this) == 's' &&
+                IterImpl.readByte(this) == 'e') {
+                return false;
+            }
+            throw reportError("readBoolean", "expect false");
         }
-        throw reportError("readBoolean", "expect t or f, found: " + c);
+        throw reportError("readBoolean", "expect true or false");
     }
 
     public final short readShort() throws IOException {