{"record":{"id":"371eb6a6d22a91bf","repo":"apache/flink","slug":"no-jar-found-on-classpath-please-provide-a-jar-ex","errorCode":null,"errorMessage":"No JAR found on classpath. Please provide a JAR explicitly.","messagePattern":"No JAR found on classpath\\. Please provide a JAR explicitly\\.","errorType":"exception","errorClass":"FlinkException","httpStatus":null,"severity":"error","filePath":"flink-clients/src/main/java/org/apache/flink/client/deployment/application/FromClasspathEntryClassInformationProvider.java","lineNumber":164,"sourceCode":"        return extractJobClassNameFromFileClasspath(extractSystemClasspath());\n    }\n\n    private static String extractJobClassFromUrlClasspath(Iterable<URL> classpath)\n            throws IOException, FlinkException {\n        final List<File> jarFilesFromClasspath =\n                StreamSupport.stream(classpath.spliterator(), false)\n                        .map(url -> new File(url.getFile()))\n                        .filter(f -> isJarFilename(f.getName()))\n                        .collect(Collectors.toList());\n        return extractJobClassNameFromFileClasspath(jarFilesFromClasspath);\n    }\n\n    private static String extractJobClassNameFromFileClasspath(Iterable<File> classpath)\n            throws FlinkException, IOException {\n        try {\n            return JarManifestParser.findOnlyEntryClass(classpath).getEntryClass();\n        } catch (NoSuchElementException e) {\n            throw new FlinkException(\n                    \"No JAR found on classpath. Please provide a JAR explicitly.\", e);\n        } catch (IllegalArgumentException e) {\n            throw new FlinkException(\n                    \"Multiple JAR archives with entry classes found on classpath. Please provide an entry class name.\",\n                    e);\n        }\n    }\n\n    private static boolean isJarFilename(String filename) {\n        return filename.endsWith(\".jar\");\n    }\n}\n","sourceCodeStart":146,"sourceCodeEnd":177,"githubUrl":"https://github.com/apache/flink/blob/2f3c205e9266cb30240eb7f4fdab15cad629a70f/flink-clients/src/main/java/org/apache/flink/client/deployment/application/FromClasspathEntryClassInformationProvider.java#L146-L177","documentation":"Error \"No JAR found on classpath. Please provide a JAR explicitly.\" thrown in apache/flink.","triggerScenarios":"Triggered at runtime when the operation fails because: No JAR found on classpath. Please provide a JAR explicitly.","commonSituations":"Commonly caused by misconfiguration, missing dependencies or files, unsupported types or operations, or invalid user input leading to: No JAR found on classpath. Please provide a JAR explicitly.","solutions":["Address the cause reported by the error message: No JAR found on classpath. Please provide a JAR explicitly.","Verify the inputs, configuration values, and classpath/dependency setup related to this operation, then retry."],"exampleFix":"Correct the condition described (\"No JAR found on classpath. Please provide a JAR explicitly.\") and rerun the job or command.","handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"2f3c205e9266cb30240eb7f4fdab15cad629a70f","analyzedAt":"2026-08-14T08:48:24.518Z","schemaVersion":2},"datasetVersion":"2026-08-14T10:17:34.591Z"}