Groovy built-in REST/HTTP client?
Solution 1
Native Groovy GET and POST
// GET
def get = new URL("https://httpbin.org/get").openConnection();
def getRC = get.getResponseCode();
println(getRC);
if (getRC.equals(200)) {
println(get.getInputStream().getText());
}
// POST
def post = new URL("https://httpbin.org/post").openConnection();
def message = '{"message":"this is a message"}'
post.setRequestMethod("POST")
post.setDoOutput(true)
post.setRequestProperty("Content-Type", "application/json")
post.getOutputStream().write(message.getBytes("UTF-8"));
def postRC = post.getResponseCode();
println(postRC);
if (postRC.equals(200)) {
println(post.getInputStream().getText());
}
Solution 2
If your needs are simple and you want to avoid adding additional dependencies you may be able to use the getText()
methods that Groovy adds to the java.net.URL
class:
new URL("http://stackoverflow.com").getText()
// or
new URL("http://stackoverflow.com")
.getText(connectTimeout: 5000,
readTimeout: 10000,
useCaches: true,
allowUserInteraction: false,
requestProperties: ['Connection': 'close'])
If you are expecting binary data back there is also similar functionality provided by the newInputStream()
methods.
Solution 3
The simplest one got to be:
def html = "http://google.com".toURL().text
Solution 4
You can take advantage of Groovy features like with(), improvements to URLConnection, and simplified getters/setters:
GET:
String getResult = new URL('http://mytestsite/bloop').text
POST:
String postResult
((HttpURLConnection)new URL('http://mytestsite/bloop').openConnection()).with({
requestMethod = 'POST'
doOutput = true
setRequestProperty('Content-Type', '...') // Set your content type.
outputStream.withPrintWriter({printWriter ->
printWriter.write('...') // Your post data. Could also use withWriter() if you don't want to write a String.
})
// Can check 'responseCode' here if you like.
postResult = inputStream.text // Using 'inputStream.text' because 'content' will throw an exception when empty.
})
Note, the POST will start when you try to read a value from the HttpURLConnection, such as responseCode
, inputStream.text
, or getHeaderField('...')
.
Solution 5
HTTPBuilder is it. Very easy to use.
import groovyx.net.http.HTTPBuilder
def http = new HTTPBuilder('https://google.com')
def html = http.get(path : '/search', query : [q:'waffles'])
It is especially useful if you need error handling and generally more functionality than just fetching content with GET.
smeeb
Updated on April 22, 2021Comments
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smeeb about 3 years
I heard that Groovy has a built-in REST/HTTP client. The only library I can find is HttpBuilder, is this it?
Basically I'm looking for a way to do HTTP GETs from inside Groovy code without having to import any libraries (if at all possible). But since this module doesn't appear to be a part of core Groovy I'm not sure if I have the right lib here.