#fixed code
                                public boolean isConfigOk() {
        if (configOk != null) {
            return configOk;
        }
        synchronized (this) {
            if (configOk == null) {
                configOk = uri != null && uri.length > 0;
                if (configOk) {
                    ensureUriConfigCorrect();
                }
            }
        }
        return configOk;
    }
#vulnerable code 
                                public boolean isConfigOk() {
        if (configOk != null) {
            return configOk;
        }
        synchronized (this) {
            if (configOk == null) {
                configOk = StrUtil.isNotBlank(uri);
                if (configOk) {
                    ensureUriConfigCorrect();
                }
            }
        }
        return configOk;
    } 
                            #location 3 
                            #vulnerability type THREAD_SAFETY_VIOLATION