Tencent/APIJSON · error · IllegalArgumentException

字符 " + function + " 不合法！

Error message

字符 " + function + " 不合法！

What it means

AbstractFunctionParser.invoke(function, current) validates that the remote-function expression is a non-blank string before parsing it. An empty, null-equivalent, or whitespace-only function string is rejected immediately with IllegalArgumentException because it cannot possibly match the required function(key0,key1,...) grammar.

Source

Thrown at APIJSONORM/src/main/java/apijson/orm/AbstractFunctionParser.java:387

	/**反射调用
	 * @param function 例如get(object,key)，参数只允许引用，不能直接传值
	 * @param current 不作为第一个参数，就不能远程调用invoke，避免死循环
	 * @return {@link #invoke(String, M, boolean)}
	 */
	@Override
	public Object invoke(@NotNull String function, @NotNull M current) throws Exception {
		return invoke(function, current, false);
	}
	/**反射调用
	 * @param function 例如get(object,key)，参数只允许引用，不能直接传值
	 * @param current 不作为第一个参数，就不能远程调用invoke，避免死循环
	 * @param containRaw 包含原始 SQL 片段
	 * @return {@link #invoke(AbstractFunctionParser, String, M, boolean)}
	 */
	@Override
	public Object invoke(@NotNull String function, @NotNull M current, boolean containRaw) throws Exception {
		if (StringUtil.isEmpty(function, true)) {
			throw new IllegalArgumentException("字符 " + function + " 不合法！");
		}

		return invoke(this, function, current, containRaw);
	}

	/**反射调用
	 * @param parser
	 * @param function 例如get(Map:map,key)，参数只允许引用，不能直接传值
     * @param current
     * @return {@link #invoke(AbstractFunctionParser, String, Class[], Object[])}
	 */
	@SuppressWarnings({"unchecked", "rawtypes"})
	public static <T, M extends Map<String, Object>, L extends List<Object>> Object invoke(
			@NotNull AbstractFunctionParser<T, M, L> parser, @NotNull String function
			, @NotNull Map<String, Object> current, boolean containRaw) throws Exception {
        if (ENABLE_REMOTE_FUNCTION == false) {
            throw new UnsupportedOperationException("AbstractFunctionParser.ENABLE_REMOTE_FUNCTION" +
                    " == false 时不支持远程函数！如需支持则设置 AbstractFunctionParser.ENABLE_REMOTE_FUNCTION = true ！");

View on GitHub (pinned to 5284052872)

Solutions

1. Check StringUtil.isEmpty(function, true) before invoking and skip or default.
2. Fix the source of the function string (config value, DB column, request field) so it is a valid expression.
3. Log the offending request payload to find which field carried the blank function.

Example fix

// before
Object v = parser.invoke(functionName, current); // functionName may be ""

// after
if (StringUtil.isEmpty(functionName, true) == false) {
    Object v = parser.invoke(functionName, current);
}

if (StringUtil.isEmpty(function, true)) {
    // skip, log, or reject early with context about which field was blank
}

public static boolean isNonBlankFunctionExpr(String f) {
    return StringUtil.isNotEmpty(f, true) && f.indexOf('(') > 0 && f.lastIndexOf(')') == f.length() - 1;
}

When it happens

Trigger: Calling parser.invoke("", current) or invoke(" ", current); typically the function string was built dynamically (string concatenation, config lookup returning empty) and turned out blank.

Common situations: Function name read from a config/DB column that is NULL/empty; template interpolation that produced an empty string; request JSON has "@column" or similar containing an empty function expression.

Related errors

• 字符 {} 不合法！远程函数不允许指定类名！且必须为 function(key0,key1,...) 这种单函数格式！\
• {}/{}:value 中 value 必须为函数String！
• Cannot convert value of type " + value.getClass().getName()
• AbstractFunctionParser.ENABLE_REMOTE_FUNCTION == false 时不支持远
• 不允许调用远程函数 " + fb.getMethod() + " !

AI-assisted analysis of Tencent/APIJSON@5284052872 (2026-08-14). Data as JSON: /api/errors/a06f6eb322160af5. Report an issue: GitHub.