Tencent/APIJSON · error · ClassNotFoundException

找不到脚本语言 " + lang + " 对应的执行引擎！请先依赖相关库并在后端 APIJSONFunctionPars

Error message

找不到脚本语言 " + lang + " 对应的执行引擎！请先依赖相关库并在后端 APIJSONFunctionParser<T, M, L> 中注册！

What it means

The Function row declares a script language, script functions are enabled, but no ScriptExecutor for that language was registered in SCRIPT_EXECUTOR_MAP. APIJSON throws ClassNotFoundException telling you to add the language's library dependency and register its executor in the backend's APIJSONFunctionParser subclass.

Source

Thrown at APIJSONORM/src/main/java/apijson/orm/AbstractFunctionParser.java:424

        }

		FunctionBean fb = parseFunction(function, current, false, containRaw);

		Map<String, Object> row = FUNCTION_MAP.get(fb.getMethod()); //FIXME  fb.getSchema() + "." + fb.getMethod()
		if (row == null) {
			throw new UnsupportedOperationException("不允许调用远程函数 " + fb.getMethod() + " !");
		}

        String language = (String) row.get("language");
        String lang = "java".equalsIgnoreCase(language) ? null : language;

        if (ENABLE_SCRIPT_FUNCTION == false && lang != null) {
            throw new UnsupportedOperationException("language = " + language + " 不合法！AbstractFunctionParser.ENABLE_SCRIPT_FUNCTION" +
                    " == false 时不支持远程函数中的脚本形式！如需支持则设置 AbstractFunctionParser.ENABLE_SCRIPT_FUNCTION = true ！");
        }

		if (lang != null && SCRIPT_EXECUTOR_MAP.get(lang) == null) {
			throw new ClassNotFoundException("找不到脚本语言 " + lang + " 对应的执行引擎！请先依赖相关库并在后端 APIJSONFunctionParser<T, M, L> 中注册！");
		}

		int version = row.get("version") != null ? Integer.parseInt(row.get("version").toString()) : 0;
		if (parser.getVersion() < version) {
			throw new UnsupportedOperationException("不允许 version = " + parser.getVersion() + " 的请求调用远程函数 " + fb.getMethod() + " ! 必须满足 version >= " + version + " !");
		}
		String tag = (String) row.get("tag");  // TODO 改为 tags，类似 methods 支持多个 tag。或者干脆不要？因为目前非开放请求全都只能后端指定
		if (tag != null && tag.equals(parser.getTag()) == false) {
			throw new UnsupportedOperationException("不允许 tag = " + parser.getTag() + " 的请求调用远程函数 " + fb.getMethod() + " ! 必须满足 tag = " + tag + " !");
		}
		String[] methods = StringUtil.split((String) row.get("methods"));
		List<String> ml = methods == null || methods.length <= 0 ? null : Arrays.asList(methods);
		if (ml != null && ml.contains(parser.getMethod().toString()) == false) {
			throw new UnsupportedOperationException("不允许 method = " + parser.getMethod() + " 的请求调用远程函数 " + fb.getMethod() + " ! 必须满足 method 在 " + Arrays.toString(methods) + "内 !");
		}

		try {
            return invoke(parser, fb.getMethod(), fb.getTypes(), fb.getValues(), (String) row.get("returnType"), current, SCRIPT_EXECUTOR_MAP.get(lang));

View on GitHub (pinned to 5284052872)

Solutions

Add the script engine dependency (e.g. org.graalvm.js:js) to the backend build.
Register an executor at startup: AbstractFunctionParser.putScriptExecutor("javascript", new JavaScriptExecutor()).
Or change the Function row's language to 'java' and implement it as a Java remote function.
Verify the language string matches exactly (case) what you registered.

Example fix

// before: language='javascript' row, no executor

// after
static {
    AbstractFunctionParser.putScriptExecutor("javascript", new JavaScriptExecutor());
}

Defensive patterns

Strategy: validation

Validate before calling

String lang = (String) functionRow.get("language");
if (lang != null && !"java".equalsIgnoreCase(lang)
        && AbstractFunctionParser.SCRIPT_EXECUTOR_MAP.get("java".equalsIgnoreCase(lang) ? null : lang) == null) {
    // missing executor: register one or change the row language
}

Try / catch

try { parser.invoke(fn, current); } catch (ClassNotFoundException e) { if (e.getMessage().contains("执行引擎")) { /* register ScriptExecutor + dependency */ } throw e; }

Prevention

Register all script executors in the same startup init block, keyed exactly to the language strings used in Function rows.
Pin script engine dependencies in the build file and verify them in a startup self-test.
Keep a checklist mapping language string -> dependency -> executor class.

When it happens

Trigger: Function row language='python' (for example) and no putScriptExecutor('python', ...) call exists; or the executor registration code lives in a demo class that was not ported to the real backend.

Common situations: Migrating from the APIJSON demo project but omitting the executor registration init; upgrading removed an optional script-engine dependency (e.g. GraalJS) from the classpath.

Related errors

AI-assisted analysis of Tencent/APIJSON@5284052872 (2026-08-14). Data as JSON: /api/errors/335ac4440dc775e5. Report an issue: GitHub.