Tencent/APIJSON · warning · WrongMethodTypeException

远程函数 " + methodName + " 的实际返回值类型 " + (rt == null ? null : rt

Error message

远程函数 " + methodName + " 的实际返回值类型 " + (rt == null ? null : rt.getName()) + " 与 Function 表中的配置的 " + fullReturnType + " 不匹配！

What it means

Debug-mode check in invokeScript: after a script (non-Java) remote function executes, if the result's null-ness disagrees with the configured returnType in the Function table (result null but returnType set, or result non-null but returnType null/void), APIJSON throws WrongMethodTypeException. It catches scripts that returned undefined/null when they promised a value, or vice versa.

Source

Thrown at APIJSONORM/src/main/java/apijson/orm/AbstractFunctionParser.java:544

     * @param args
     * @param returnType
     * @param current
     * @return
     * @throws Exception
     */
	@SuppressWarnings({"unchecked", "rawtypes"})
    public static <T, M extends Map<String, Object>, L extends List<Object>> Object invokeScript(
			@NotNull AbstractFunctionParser<T, M, L> parser, @NotNull String methodName
            , @NotNull Class<?>[] parameterTypes, @NotNull Object[] args, String returnType
			, Map<String, Object> current, ScriptExecutor scriptExecutor) throws Exception {
    	Object result = scriptExecutor.execute(parser, current, methodName, args);
        if (Log.DEBUG && result != null) {
            Class<?> rt = result.getClass(); // 作为远程函数的 js 类型应该只有 JSON 的几种类型
            String fullReturnType = (StringUtil.isSmallName(returnType)
                    ? returnType : (returnType.startsWith("JSON") ? "com.alibaba.fastjson." : "java.lang.") + returnType);

            if ((rt == null && returnType != null) || (rt != null && returnType == null)) {
                throw new WrongMethodTypeException("远程函数 " + methodName + " 的实际返回值类型 "
                        + (rt == null ? null : rt.getName()) + " 与 Function 表中的配置的 " + fullReturnType + " 不匹配！");
            }

            Class<?> cls;
            try {
                cls = Class.forName(fullReturnType);
            }
            catch (Exception e) {
                throw new WrongMethodTypeException("远程函数 " + methodName + " 在 Function 表中的配置的类型 "
                        + returnType + " 对应的 " + fullReturnType + " 错误！在 Java 中 Class.forName 找不到这个类型！");
            }

            if (cls.isAssignableFrom(rt) == false) {
                throw new WrongMethodTypeException("远程函数 " + methodName + " 的实际返回值类型 "
                        + (rt == null ? null : rt.getName()) + " 与 Function 表中的配置的 "
                        + returnType + " 对应的 " + fullReturnType + " 不匹配！");
            }
        }

View on GitHub (pinned to 5284052872)

Solutions

Fix the script so it always returns a value of the configured type (add/repair the return statement).
Or align the Function row's returnType with what the script actually returns (set it, or clear it if the result is legitimately null).
Handle null-producing inputs inside the script with defaults.

Example fix

// before (script row returnType='Number')
function inc(x) { var v = x + 1; } // no return -> undefined

// after
function inc(x) { return x + 1; }

Defensive patterns

Strategy: validation

Validate before calling

Object result = scriptExecutor.execute(...);
String configured = (String) functionRow.get("returnType");
if ((result == null) != (configured == null || "void".equals(configured))) {
    // script null-ness disagrees with configuration: fix script or row before shipping
}

Try / catch

try { invokeScript(...); } catch (WrongMethodTypeException e) { if (e.getMessage().contains("不匹配")) { /* align script return with returnType column */ } throw e; }

Prevention

Unit-test script functions over representative inputs (including nulls) to confirm they always return the configured type.
Set returnType only when the script guarantees a value; clear it for intentionally void functions.
Exercise scripts under Log.DEBUG=true in CI.

When it happens

Trigger: Function row language='javascript' with returnType='Number', but the JS function returns undefined (e.g. missing return statement) — or a void-configured function returns a value — while Log.DEBUG is true.

Common situations: JS function edited and the return statement dropped; returnType column left empty when the script actually returns data; null returned for edge-case inputs.

Related errors

AI-assisted analysis of Tencent/APIJSON@5284052872 (2026-08-14). Data as JSON: /api/errors/7312891fbe3bafc2. Report an issue: GitHub.