json-path/JsonPath · error · InvalidPathException

Pattern not closed. Expected

Error message

Pattern not closed. Expected 

What it means

Raised in FilterCompiler.readPattern when compiling an inline regex literal (e.g. /pattern/flags) in a JSON Path filter expression: the scanner reached the end of the path without finding the unescaped closing '/' that terminates the pattern, so the literal is unterminated. It is a strict syntax guard — the offending input is a filter path containing a '/' that opens a regex but never closes it (or the closer is escaped, as in \/).

Source

Thrown at json-path/src/main/java/com/jayway/jsonpath/internal/filter/FilterCompiler.java:295

    private int endOfFlags(int position) {
        int endIndex = position;
        char[] currentChar = new char[1];
        while (filter.inBounds(endIndex)) {
            currentChar[0] = filter.charAt(endIndex);
            if (PatternFlag.parseFlags(currentChar) > 0) {
                endIndex++;
                continue;
            }
            break;
        }
        return endIndex;
    }

    private PatternNode readPattern() {
        int begin = filter.position();
        int closingIndex = filter.nextIndexOfUnescaped(PATTERN);
        if (closingIndex == -1) {
            throw new InvalidPathException("Pattern not closed. Expected " + PATTERN + " in " + filter);
        } else {
            if (filter.inBounds(closingIndex+1)) {
                int endFlagsIndex = endOfFlags(closingIndex + 1);
                if (endFlagsIndex > closingIndex) {
                    CharSequence flags = filter.subSequence(closingIndex + 1, endFlagsIndex);
                    closingIndex += flags.length();
                }
            }
            filter.setPosition(closingIndex + 1);
        }
        CharSequence pattern = filter.subSequence(begin, filter.position());
        logger.trace("PatternNode from {} to {} -> [{}]", begin, filter.position(), pattern);
        return ValueNode.createPatternNode(pattern);
    }

    private StringNode readStringLiteral(char endChar) {
        int begin = filter.position();

View on GitHub (pinned to 62a4c9f0f6)

Solutions

1. Close the regex literal with an unescaped '/' in the filter expression, e.g. @.name =~ /^ab.*c$/
2. If the pattern must contain a literal '/', escape it as \/ so it is not treated as the closing delimiter
3. If the value is not meant to be a regex, replace the '~=' operator and slash-delimited form with a plain string comparison
4. Validate the filter path string (balanced, unescaped delimiters) before passing it to JsonPath.compile/parse

When it happens

Trigger: Thrown at json-path/src/main/java/com/jayway/jsonpath/internal/filter/FilterCompiler.java:295 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of json-path/JsonPath@62a4c9f0f6 (2026-09-11). Data as JSON: /api/errors/154dd90cc1dd8db4. Report an issue: GitHub.