Intellij Idea's debugger renders object to string in object view (Preferences -> Build, Execution, Deployment -> Debugger -> Data Views -> Java -> Enable 'toString()' object view). This behavior is enabled by default and it leads some strange problem when debug in Dubbo, for examples: #2431, or user may observe a ReferenceConfig may init twice or ReferenceConfig#urls may have two same entries if the breakpoint happens to set in the relevant places. You may interested in looking into the details from http://t.cn/EAhta27, where @code4wt gives the excellent analysis.
@SuppressWarnings("unchecked")
    protected static void appendParameters(Map<String, String> parameters, Object config, String prefix) {
        if (config == null) {
            return;
        }
        Method[] methods = config.getClass().getMethods();
        for (Method method : methods) {
            try {
                String name = method.getName();
                if ((name.startsWith("get") || name.startsWith("is"))
                        && !"getClass".equals(name)
                        && Modifier.isPublic(method.getModifiers())
                        && method.getParameterTypes().length == 0
                        && isPrimitive(method.getReturnType())) {
                    Parameter parameter = method.getAnnotation(Parameter.class);
                    if (method.getReturnType() == Object.class || parameter != null && parameter.excluded()) {
                        continue;
                    }
                    int i = name.startsWith("get") ? 3 : 2;
                    String prop = StringUtils.camelToSplitName(name.substring(i, i + 1).toLowerCase() + name.substring(i + 1), ".");
                    String key;
                    if (parameter != null && parameter.key().length() > 0) {
                        key = parameter.key();
                    } else {
                        key = prop;
                    }
                    Object value = method.invoke(config);
                    String str = String.valueOf(value).trim();
                    if (value != null && str.length() > 0) {
                        if (parameter != null && parameter.escaped()) {