quarkusio/quarkus · error · MessageBundleException

Message bundle method {key}() not found on: {bundleInterface

Error message

Message bundle method {key}() not found on: {bundleInterface}
	- file: {localizedFile}
	- line {index}

What it means

Every key in a localized bundle .properties file must correspond to a method on the message bundle interface (or be an enum-constant message key for enums in the bundle). When a key has no matching bundle method, the build fails, listing the key, the bundle interface, the file, and the line.

Source

Thrown at extensions/qute/deployment/src/main/java/io/quarkus/qute/deployment/MessageBundleProcessor.java:897

                    continue;
                }
                line = line.strip();
                if (line.startsWith("#")) {
                    // Comments are skipped
                    continue;
                }
                int eqIdx = line.indexOf('=');
                if (eqIdx == -1) {
                    throw new MessageBundleException(
                            "Missing key/value separator\n\t- file: " + localizedFile + "\n\t- line " + it.previousIndex());
                }
                String key = line.substring(0, eqIdx).strip();
                if (keyToTemplate.containsKey(key)) {
                    // Message template with higher priority takes precedence
                    continue;
                }
                if (!hasMessageBundleMethod(bundleInterface, key) && !isEnumConstantMessageKey(key, index, bundleInterface)) {
                    throw new MessageBundleException(
                            "Message bundle method " + key + "() not found on: " + bundleInterface + "\n\t- file: "
                                    + localizedFile + "\n\t- line " + it.previousIndex());
                }
                String value = adaptLine(line.substring(eqIdx + 1, line.length()));
                if (value.endsWith("\\")) {
                    // The logical line is spread out across several normal lines
                    StringBuilder builder = new StringBuilder(value.substring(0, value.length() - 1));
                    constructLine(builder, it);
                    keyToTemplate.put(key, builder.toString());
                } else {
                    keyToTemplate.put(key, value);
                }
            }
        }
        return keyToTemplate;
    }

    /**

View on GitHub (pinned to e1c734241f)

Solutions

1. Add the missing method to the bundle interface (with @Message/template) so the key has a source method.
2. Or remove/rename the offending line in the properties file to match an existing method key.
3. Diff all localized files against the default bundle's keys to catch every stale key at once.

Example fix

// before (messages_de.properties)
goodbye=Auf Wiedersehen
// interface has only hello()

// after
// interface:
String goodbye(String name);
// properties:
goodbye=Auf Wiedersehen {name}

// Ensure every properties key has a matching bundle method
java.util.Set<String> methods = java.util.Set.of("hello", "goodbye");
java.nio.file.Files.lines(Path.of("messages_de.properties"))
    .filter(l -> l.contains("="))
    .map(l -> l.substring(0, l.indexOf('=')).strip())
    .filter(k -> !methods.contains(k))
    .forEach(k -> { throw new IllegalStateException("No bundle method for key: " + k); });

When it happens

Trigger: A .properties file contains `goodbye=...` but the bundle interface AppMessages has no `goodbye()` method; key renamed in the interface but the properties file not updated (or vice versa); typo in the key.

Common situations: Adding translations by hand before/after changing the interface; merging locale files from another project with different keys; deleting a bundle method but leaving stale entries in de/fr/es properties files.

Related errors

• Missing key/value separator - file: {localizedFile} - line
• A localized message bundle interface must extend a message b
• @Localized must be declared on an interface: {localized}
• Default bundle method not found on %s: %s
• No suitable template variant found

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/d4230eb637ed8a16. Report an issue: GitHub.