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.
}
    protected String id;
    private static String convertLegacyValue(String key, String value) {
        if (value != null && value.length() > 0) {
            if ("dubbo.service.max.retry.providers".equals(key)) {
                return String.valueOf(Integer.parseInt(value) - 1);
            } else if ("dubbo.service.allow.no.provider".equals(key)) {
                return String.valueOf(!Boolean.parseBoolean(value));
            }
        }
        return value;
    }
    protected static void appendProperties(AbstractConfig config) {
        if (config == null) {
            return;
        }
        String prefix = "dubbo." + getTagName(config.getClass()) + ".";
        Method[] methods = config.getClass().getMethods();
        for (Method method : methods) {
            try {
                String name = method.getName();
                if (name.length() > 3 && name.startsWith("set") && Modifier.isPublic(method.getModifiers())
                        && method.getParameterTypes().length == 1 && isPrimitive(method.getParameterTypes()[0])) {
                    String property = StringUtils.camelToSplitName(name.substring(3, 4).toLowerCase() + name.substring(4), ".");
                    String value = null;
                    if (config.getId() != null && config.getId().length() > 0) {
                        String pn = prefix + config.getId() + "." + property;
                        value = System.getProperty(pn);
                        if (!StringUtils.isBlank(value)) {
                            logger.info("Use System Property " + pn + " to config dubbo");