Downloading CSV from web server

Processing Coding Questions
1

I have a CSV that constantly gets updated on a web server. How can I download the data? I already have code for processing if the data exists locally, but I’d rather not have to store it locally and just read it from the web server. Is this even possible?

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2

Hey and welcome in this great community!

Look here

https://www.processing.org/reference/loadStrings_.html

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3

Thanks! That works - but any idea what I can do if I have to manually allow a certificate? I can pull my csv data in a browser, but I get:








javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at sun.security.ssl.Alerts.getSSLException(Alerts.java:192)
	at sun.security.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1946)
	at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:316)
NullPointerException
	at sun.security.ssl.Handshaker.fatalSE(Handshaker.java:310)
	at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1639)
	at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:223)
	at sun.security.ssl.Handshaker.processLoop(Handshaker.java:1037)
	at sun.security.ssl.Handshaker.process_record(Handshaker.java:965)
	at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1064)
	at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1367)
	at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1395)
	at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1379)
	at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:559)
	at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1564)
	at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1492)
	at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:480)
	at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:347)
	at processing.core.PApplet.createInputRaw(PApplet.java:7145)
	at processing.core.PApplet.createInputRaw(PApplet.java:7150)
	at processing.core.PApplet.createInput(PApplet.java:7098)
	at processing.core.PApplet.loadStrings(PApplet.java:7561)
	at sketch_190625a.setup(sketch_190625a.java:17)
	at processing.core.PApplet.handleDraw(PApplet.java:2425)
	at processing.awt.PSurfaceAWT$12.callDraw(PSurfaceAWT.java:1547)
	at processing.core.PSurfaceNone$AnimationThread.run(PSurfaceNone.java:313)
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:397)
	at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:240)
	at sun.security.validator.Validator.validate(Validator.java:262)
	at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:324)
	at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:229)
	at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:124)
	at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1621)
	... 21 more
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
	at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:141)
	at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:126)
	at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
	at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:392)
	... 27 more
The file "<https://server.com/file.csv>" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable.
4

I don’t know

@GoToLoop ?

5

also not see a file there…

anyhow you not load a CSV file with loadStrings,
a table fits much better, look at all that features available for this:

Table table;

void setup() { 
  table = loadTable("http://kll.engineering-news.org/kllfusion01/downloads/song.csv"); //, "header");
  println(table.getRowCount() + " total rows in table"); 
}
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6

Yes, loadTable() is much better. Thank you. Unfortunately I still can’t get past the ssl errors. And just for clarity, I removed my actual server and just put this in:
“https://server.com/file.csv” as a placeholder.