I have an app [Android] that will basically give me numbers and I need those numbers to be sent to a website hosted via "Apache" (Haven't worked that out yet).
The reason why I am asking it here is because I do not know the first thing about making applications connect to a website in way where it updates a variable each time it is calculated on that app.
Any few tips or advises would be great! [I know how to use HTML, a bit of java scripting, MySQL and lots of java]
What language should I be using. How does the server work and how do we make the app and the website work concurrently, or in parallel?
This is question is too broad, still I am listing few ways
Generate the data on application
Send a custom broadcast whenever the data is generated.
Start an Intent service from the Broadcast Receiver.
Post to server i.e to a REST or SOAP service using Http post and basic name value pairs.
At your server side, you need a service which receives the posted data and saves it to the database or any where you want.
Related
I made a web-server that runs on an esp32(LAN) and I have made it possible to send information to the esp itself from the servers url, (example : 192.168.1.39/?userInput=123), the number 123 is what I want to send from the application depends on the user's input (I compiled it to a packet of 8bits) so max number is 255, the server has an XML and some basic UI for viewing the information passed back and forth, I wanna be able to send the so called packet to the server and it passing it to the esp32 with almost no delay, I used google firebase before but it has way too much delay for it to be usable, I tried using a WebView and loading the URL with the number from the packet, I ran out of ideas on how to approach this would love some advice :)
I tried searching other questions here on the site, asked friends/teachers, watched a few tutorials and asked chatGPT for help but nothing was helpful.
From reading your question it seems you are lost setting up server and client at the same time. Divide the tasks into chunks you can digest:
First, setup your ESP32 webserver. Follow a tutorial like https://randomnerdtutorials.com/esp32-web-server-arduino-ide/ and test it using a normal web browser. It can be used to run GET requests easily, and the amount of data you need to transfer that should definitely be enough. Alternatively you can use curl to send client requests.
Next, develop your java client to send the appropriate request. You can test the behaviour using any standard webserver and check the logs.
Finally put the ESP32 url into your client and see whether they work together.
I am creating an app using React-Native for the front-end, Java for the back-end and PostgreSQL for the database.
One feature of this app is to allow users to add each other as friends and instant message them - just like other social networks. At the moment, security is not a priority but I don't want to create something that I will have to completely redo when I do have to make it secure!
The goal here is to give each user the ability to send/receive messages to/from their friends. They also need to be able to view the message history with each contact.
I just need some advice on the following points to get me going as I haven't gotten very far on my own:
How should I send messages from the front-end, to the Java server and then to the receiver? This will involve the app having to listen for new messages so would the Socket.IO library be the way to go for this?
How I should store the messages in the database? E.g. have a table for messages with user_ids to be used for retrieval?
I should point out that I am very new to React-Native, databases and networking so I am finding this very challenging!
I will massively appreciate any help and any examples would be fantastic!
You should use WebSocket on the server. Spring supports it
Here's a tutorial I wrote about sending messages from PostgreSQL to the browser using WebSocket, which isn't exactly what you're going to do, but can hopefully get you started:
http://blog.databasepatterns.com/2014/04/postgresql-nofify-websocket-spring-mvc.html
I've been looking around all morning, and can't seem to figure this one out. I know it's not as complicated as I think it is, and all I need is just some pointers to the right direction.
I have an Android application that takes some user input, sends it to a Java application over the web, and then receives some output based on the input.
My Android and Java applications are ready, but how do I go about sending and receiving the data over the web? I understand that I'll be sending and receiving HTTP requests, but my problem is where I'll be sending them and receiving them from. Do I host my Java application on a Servlet like Tomcat, or do I use something like OpenShift to host my application for me?
I have no trouble with sending some HTTP request from my Android application to the web and receiving some output back, but my problem is that my web service needs to use a Java library to process the input and generate the output. I'm just not sure how I'm supposed to get this data to and from this Java library that needs to be hosted on the web.
I hope my question makes any sense.
EDIT: Perhaps I wasn't clear with what exactly I need help with. I do realize that the architecture I use doesn't really make any difference, but the problem I have is with how I'm supposed to use this architecture.
Let's say I have a registered domain name that I can easily send to and receive data from using my Android application - no trouble with that. But how am I supposed to integrate my Java library with this server? Do I just create an applet and put it on my server? Does my web host even allow Java applets to run?
I guess my question is how I'm supposed to get through the "barrier" between my HTTP request / transport layer protocol and my Java application.
Server architecture usually does not matter. You can use Java, NodeJs, Rails, Python, .NET, etc. You just need an endpoint that accepts a HTTP POST/PUT/GET/DELETE/PATCH verb.
This is more a question of "how do I set up a server to accept input" and its a very large topic in itself. I would advise you look at PAAS solutions like:
Parse.com
Kinvey.com
You can use their tools to build a solution fairly quickly. If you need something custom you'll need to build your backend in the language of choice and host it online via AWS, Google Cloud, Heroku, a VPS or something similar.
I currently have an small application that I have been using to learn java/android programming. Right now I have a setup were the app on one phone sends a request (via sms) to another phone running the same app. The remote phone receives the request and sends back some info. Next I would like to try this from the web. Is there an established "best" way to to this?
I was thinking I would have a web server send requests to the device via google cloud messaging and then have the device return the data directly to the web server. (Not that I really know how to do any of that just yet).
I see that there is a google cloud messaging return path (send messages from the device to the google cloud server, but it seems very new, do I need something like that? The main thing I want is to be able to ask the phone to do something when I want, not have it poll to see if there is a request, or just periodically update some status.
UPDATE:
Thanks to the answers below for confirming to me that I was on the right track.
I now have some basic functionality.
I started out using this gcm android demo code
https://code.google.com/p/gcm/source/browse/#git%2Fgcm-client%2Fsrc%2Fcom%2Fgoogle%2Fandroid%2Fgcm%2Fdemo%2Fapp%253Fstate%253Dclosed
and this ruby gem
https://github.com/spacialdb/gcm/blob/master/README.md
between the above two I was able to send a message to my phone pretty easily.
To get the round trip working, I setup a very simple rails app on heroku.
I included a modified version of the sample code in the gcm gem in a controller and then used
HttpPatch (needed for rails 4) to send a post/patch from my phone to my web app, the controller then echoes the message back to my phone.
I guess it would be nice to get the two way gcm stuff to work, but I am not sure there are any gems that handle that, and I am not qualified to handle a task like that :)
I would say it's the right call: Google Cloud Messaging for Android
From the site Android Developer:
This could be a lightweight message telling your app there is new data
to be fetched from the server (for instance, a movie uploaded by a
friend), or it could be a message containing up to 4kb of payload data
(so apps like instant messaging can consume the message directly).
In this case you don't want to fetch data from the server but you want to send them.
You can send them in different ways. I would suggest, since you are learning, to try a RESTful solution using one of the implementation of JAX-RS.
As a short and direct answer for beginner : GCM (Google Cloud Messaging) would solve your issue. However, if your app turned out to be something bigger, other more technical and complicated solutions are present too.
see this link.
I am new to Java and Android. I am just beginning work on an app that will save information to a server that someone else from within the same company can retrieve using the same app from a different android device. I know how to simply store data on a server using simple php scripts but this is a bit more complex and involves one user writing information to the server, while another user can see / download it. Within a company there would be multiple users who have acceess to this data. So my question would be, whats the best way to implement a company-wide database that ONLY members of the same company can have access to? Sorry if this seems obvious to some of you. I am just getting started and I have 7 books on android programming and none of them describe how to do quite what I am trying to do.
To do this you need to use Android network services to access data. In other words to retrieve a networked database information your device will connect to your service with a specified URL and arguments. In turn, the service will reply with the required data, say may be in XML format. All your app needs to do is parse the XMl and display the date as desired.
Same thing applies to putting data into the server, in this case however the data will be sent as arguments to the network service URL and the service will handle the persistence to a database.
My advise is to do a Google search of the keyword "Android Network Services".