Accessing web server application from server itself?

Question

I have downloaded a web server program, and when launched it gives an IP address to access it through port 8080. However, nothing happens, so I can draw the conclusion at these possible problems:

1. The server is not pointing to any files, hence, nothing shows when you type that IP address and port number in the browser. In such a case, I can't figure out how to configure the server, and the developers do not explain in good detail.
2. There's an issue with accessing port 8080, which would be a restriction by the kernel or a related sort(unrooted operating system).
3. The server doesn't work correctly.

Now, in general, the program is installed in the SD card, the SD card is obviously mounted, and it automatically is set to access itself in directory format as follows: mnt/sdcard/server/

However, the HTML files are stored following: /server/HTML/index.html

I do not know how it is, by default, configured, and there's very many configuration files in Extensive Markup Language(XML). So, these following questions I directly ask:

1. Is there any default blocking of port 8080, or otherwise noteworthy issues that could explain this port number, the local machine connection to it, etc.?
2. Is accessing data from the server while on the server problematic?
3. Is there any standard way server software is configured/set up(so I could maybe tweak around with a goal specifically in mind)?

The server app is: PAW server. Despite following its instructions just fine, nothing loads when the IP address is typed in, and a "welcome page" reportedly should.

What I've tried:

1. Accessing the IP address without the port number; nothing happens.
2. Changing the directory the app points to; app doesn't work then.
3. Changing the files in the HTML directory; still nothing.
4. Digging through and editing some presets that seemed off in some XML files; still nothing.
5. Changing the port number; still nothing.
6. Accessing from another device; still won't load the page.
7. Using HTTPS instead of HTTP; still doesn't work.
8. Adjusting browser's settings, trying different browsers, etc.; still doesn't work.

^{Screenshots (click to enlarge)}

PAW is supposed to show a "welcome/sign in" page by default configuration, I believe.

Answer 1

No, there's no default blocking of port 8080, accessing an HTTP server from the same machine doesn't itself cause a problem, and there's no standard way to configure a server. The standard way to configure anything in Android is through the application itself, with the GUI it provides, not by editing XML files.

After trying everything you have, I'd suggest it would be best to ask the developer for help directly.

Answer 2

Try accessing your server using the address: http://localhost:8080/ or http://127.0.0.1:8080/

Those are called loopback address and should always refer to the machine running the program.

Is there any default blocking of port 8080, or otherwise noteworthy issues that could explain this port number, the local machine connection to it, etc.?

Unless your device is configured otherwise (e.g. with firewall or iptables), when an application have privilege to full access to the internet, they will be able to connect to any port and listen to non privileged ports (specifically > 1024).

Many network providers have firewall which blocks incoming ports, which can interfere with your ability to connect to a device if you are using your external IP address or machine name. loopback addresses are resolved locally and can only be blocked by a local firewall.

Is accessing data from the server while on the server problematic?

No it isn't, and it shouldn't.

Is there any standard way server software is configured/set up(so I could maybe tweak around with a goal specifically in mind)?

Refer to your web server documentation.