{"id":"e445e328b7f0a1e7","repo":"spring-projects/spring-framework","slug":"invalid-method-signature-signature-expected","errorCode":null,"errorMessage":"Invalid method signature '${signature}': expected closing ')' for args list","messagePattern":"Invalid method signature '(.+?)': expected closing '\\)' for args list","errorType":"exception","errorClass":"IllegalArgumentException","httpStatus":null,"severity":"error","filePath":"spring-beans/src/main/java/org/springframework/beans/BeanUtils.java","lineNumber":458,"sourceCode":"\t * argument type list, only the method whose name and argument types match will be returned.\n\t * <p>Note then that {@code methodName} and {@code methodName()} are <strong>not</strong>\n\t * resolved in the same way. The signature {@code methodName} means the method called\n\t * {@code methodName} with the least number of arguments, whereas {@code methodName()}\n\t * means the method called {@code methodName} with exactly 0 arguments.\n\t * <p>If no method can be found, then {@code null} is returned.\n\t * @param signature the method signature as String representation\n\t * @param clazz the class to resolve the method signature against\n\t * @return the resolved Method\n\t * @see #findMethod\n\t * @see #findMethodWithMinimalParameters\n\t */\n\tpublic static @Nullable Method resolveSignature(String signature, Class<?> clazz) {\n\t\tAssert.hasText(signature, \"'signature' must not be empty\");\n\t\tAssert.notNull(clazz, \"Class must not be null\");\n\t\tint startParen = signature.indexOf('(');\n\t\tint endParen = signature.indexOf(')');\n\t\tif (startParen > -1 && endParen == -1) {\n\t\t\tthrow new IllegalArgumentException(\"Invalid method signature '\" + signature +\n\t\t\t\t\t\"': expected closing ')' for args list\");\n\t\t}\n\t\telse if (startParen == -1 && endParen > -1) {\n\t\t\tthrow new IllegalArgumentException(\"Invalid method signature '\" + signature +\n\t\t\t\t\t\"': expected opening '(' for args list\");\n\t\t}\n\t\telse if (startParen == -1) {\n\t\t\treturn findMethodWithMinimalParameters(clazz, signature);\n\t\t}\n\t\telse {\n\t\t\tString methodName = signature.substring(0, startParen);\n\t\t\tString[] parameterTypeNames =\n\t\t\t\t\tStringUtils.commaDelimitedListToStringArray(signature.substring(startParen + 1, endParen));\n\t\t\tClass<?>[] parameterTypes = new Class<?>[parameterTypeNames.length];\n\t\t\tfor (int i = 0; i < parameterTypeNames.length; i++) {\n\t\t\t\tString parameterTypeName = parameterTypeNames[i].trim();\n\t\t\t\ttry {\n\t\t\t\t\tparameterTypes[i] = ClassUtils.forName(parameterTypeName, clazz.getClassLoader());","sourceCodeStart":440,"sourceCodeEnd":476,"githubUrl":"https://github.com/spring-projects/spring-framework/blob/e8729d043887bf0d0baf91e062e909b56eb2b708/spring-beans/src/main/java/org/springframework/beans/BeanUtils.java#L440-L476","documentation":"Thrown as IllegalArgumentException by resolveSignature when the supplied signature string contains an opening '(' but no matching closing ')', making the argument list malformed (BeanUtils.java:457-460). Parsing stops before any method lookup.","triggerScenarios":"resolveSignature('foo(int', clazz) or any signature like 'doWork(String' where the closing parenthesis is missing or mistyped.","commonSituations":"Externalizing method names in properties/YAML and truncating the value; string concatenation that drops the ')'; copy-paste errors in config; whitespace/encoding corruption of the signature.","solutions":["Supply a well-formed signature with a closing ')', e.g. 'foo(int, java.lang.String)'.","If you want the minimal-arg method, omit parentheses entirely: 'foo' (see resolveSignature docs).","Validate the signature string at config load time (must contain '(' only together with a later ')').","Add a unit test that parses the configured signature against a known class."],"exampleFix":"// before\nresolveSignature(\"doWork(String\", clazz); // missing ')'\n\n// after\nresolveSignature(\"doWork(String)\", clazz);","handlingStrategy":"validation","validationCode":"int open = signature.indexOf('('), close = signature.indexOf(')');\nif (open > -1 && close == -1) {\n  throw new IllegalArgumentException(\"Malformed signature, missing ')': \" + signature);\n}","typeGuard":"public static boolean isBalancedSignature(String s) {\n  int o = s.indexOf('('), c = s.indexOf(')');\n  return (o == -1 && c == -1) || (o > -1 && c > o);\n}","tryCatchPattern":"try { BeanUtils.resolveSignature(sig, clazz); }\ncatch (IllegalArgumentException e) { /* fix the signature string */ }","preventionTips":["Validate signature strings at config load (balanced parentheses).","Omit parentheses entirely to use minimal-arg resolution.","Add unit tests covering configured method signatures."],"tags":["spring-beans","beanutils","method-signature","parsing","config"],"analyzedSha":"e8729d043887bf0d0baf91e062e909b56eb2b708","analyzedAt":"2026-08-04T19:07:39.725Z","schemaVersion":2}