Network lib with google APIs

Programming Questions

semrich

in Programming Questions • 3 years ago

Hi, first post here since I can't seem to find an answer in searches or the docs.

I'm working on a sketch that needs to grab data from google finance for a stock ticker display via arduino. I opened up the basic HTTP client example and modified it but I'm having trouble communicating with google's servers:

I need to connect to and send a POST request with my login info to "https://www.google.com/accounts/ClientLogin" server so I changed the example code to this:

import processing.net.*;
Client c;
String data;
void setup() {
size(200, 200);
background(50);
fill(200);
c = new Client(this, "https://www.google.com/accounts/ClientLogin", 80); // Connect to authentication server
c.write("POST Email=MYEMAIL&Passwd=MYPASSWORD&service=finance&source=arduino-stockticker-alpha"); // Post login data to recieve token back
}
void draw() {
if (c.available() > 0) { // If there's incoming data from the client...
data = c.readString(); // ...then grab it and print it
println(data);
}
}

But this gives me a java.net.UnknownHostException as well as a nullpoint exception. I'm assuming that's because I'm supposed to connect to a server like "google.com," not a full path like I am trying, and then the nullpoint because the client was never created.

I tried this too:

c = new Client(this, "google.com", 80); // Connect to authentication server
c.write("POST /accounts/ClientLogin HTTP/1.0");
c.write("POST Email=MYEMAIL&Passwd=PASSWORD&service=finance&source=emrich-stockticker-alpha"); // Post login data to recieve token back

and don't get any errors but also don't get a server response at all. Any idea how I'm totally screwing up use of the protocol in this way and how to format things correctly?

As a side note, I'm trying to get into google finance because it'll let give me the data in XML format so I can use processing's XML tools to grab what I need, but suggestions for a better way to get data like this are welcome too!

Thanks for your help,

Stephen

Replies(4)

PhiLho

Re: Network lib with google APIs

3 years ago

Well, I don't think the simple network library of Processing can connect to HTTPS.

semrich

Re: Network lib with google APIs

2 years ago

Thanks for the response phi.lho. Okay, google is out then.

Yahoo seems to be a good candidate for info though through their YQL requests. They take the form of

http://query.yahooapis.com/v1/public/yql?q=select+*+from+yahoo.finance.quotes+where+symbol+in+("YHOO","AAPL","GOOG","MSFT")

Yahoo says: "A Web application can use an HTTP GET request when running SELECT statements, specifying the YQL statement as a query parameter of the Web Service URL."

so I should be able to make the request from in processing and get back the xml it sends, which can be sorted with parameters of the select statement entered to reduce the parsing i'd have to do in processing. The problem is that the parenthesis in the url could be a problem, confusing processing and generating errors.

Alternatively, http://finance.yahoo.com/d/quotes.csv?s=XOM+BBDb.TO+JNJ+MSFT&f=snd1l1yr

gets a csv file.

c = new Client(this, "www.yahoo.com", 80); // Connect to server on port 80
c.write("GET http://finance.yahoo.com/d/quotes.csv?s=XOM+BBDb.TO+JNJ+MSFT&f=snd1l1yr"); // Use the HTTP "GET" command to ask for a Web page
}
void draw() {
if (c.available() > 0) { // If there's incoming data from the client...
data = c.readString(); // ...then grab it and print it
println(data);
}
}

When run, the above code gives no errors but also seems to give no data (nothing shown in the console). Can you point me to some help properly sending these GET requests in processing?

Thanks for your help,

Stephen

andreas.s..

Re: Network lib with google APIs

2 years ago

hi, gave this a try, here is how i got it to work. i changed the host (download.finance.yahoo.com), this is where yahoo will redirect your request to. and i added a line break (\n) to the GET request string.

gives me the following output in my console

"XOM","Exxon Mobil Corpo","11/4/2010",69.38,2.53,12.04

"BBD-B.TO","BOMBARDIER INC., ","11/4/2010",5.05,1.99,14.25

"JNJ","Johnson & Johnson","11/4/2010",64.76,3.21,13.18

"MSFT","Microsoft Corpora","11/4/2010",27.14,1.92,11.62

import processing.net.*;
Client c;
void setup() {
// host is download.finance.yahoo.com
c = new Client(this, "download.finance.yahoo.com", 80); // Connect to server on port 80
// add a line break at the end of your get request
c.write("GET http://download.finance.yahoo.com/d/quotes.csv?s=XOM+BBDb.TO+JNJ+MSFT&f=snd1l1yr\n"); // Use the HTTP "GET" command to ask for a Web page
}
void draw() {
if (c.available() > 0) { // If there's incoming data from the client...
String data = c.readString(); // ...then grab it and print it
println(data);
}
}

andreas schlegel, http://www.sojamo.de

semrich

Re: Network lib with google APIs

2 years ago

Thanks Andreas, that's just what I needed.

Very cool stuff on your site btw. I'm going to play with controlP5 some as it might give me a great way to make a little GUI for this project.

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