Requests is a http request lib for java, using HttpClient as backend and with fluent api.
- Maven Setting
- Requests
- Simple http request
- Request Charset
- Passing Parameters
- Custom Headers
- Cookies
- Request with data
- Basic Auth
- Client
- Redirection
- Timeout
- Response compress
- Https Verification
- Proxy
- Session
- Exceptions
#Maven Setting Requests is now in maven central repo.
<dependency>
<groupId>net.dongliu</groupId>
<artifactId>requests</artifactId>
<version>2.1.5</version>
</dependency>A Requests class is provided to make plain, simple http requests ##Simple http request Simple example that do http get request:
String url = ...;
Response<String> resp = Requests.get(url).text();Post and other method:
resp = Requests.post(url).text();
resp = Requests.head(url).text();
...The response object have several common http response fields can be used:
Response<String> resp = Requests.get(url).text();
int statusCode = resp.getStatusCode();
Headers headers = resp.getHeaders();
Cookies cookies = resp.getCookies();
String body = resp.getBody();The text() method here trans http response body as String, more other methods provided:
// get response as string, use encoding get from response header
Response<String> resp = Requests.get(url).text();
// get response as string, and use provided encoding
Response<String> resp = Requests.get(url).text(StandardCharsets.UTF-8);
// get response as bytes
Response<byte[]> resp1 = Requests.get(url).bytes();
// save response as file
Response<File> resp2 = Requests.get(url).file("/path/to/save/file");or you can custom http response processor your self:
Response<String> resp = Requests.get(url).handle(new ResponseHandler<String>() {...});##Request Charset Set charset used to encode parameters, post forms or request string body:
Response<String> resp = Requests.get(url).charset(StandardCharsets.UTF_8).text();
Default charset is utf-8.
##Passing Parameters Pass parameters in urls using param or params method:
Response<String> resp = Requests.get(url)
// add one param
.addParam("key1", "value1")
.addParam("key1", "value1")
.text();
// set params by map
Map<String, Object> params = new HashMap<>();
params.put("k1", "v1");
params.put("k2", "v2");
Response<String> resp = Requests.get(url).params(params).text();
// set multi params
Response<String> resp = Requests.get(url).params(new Parameter(...), new Parameter(...))
.text();If you want to send post form-encoded paramters, use form()/forms() methods ##Custom Headers Http request headers can be set by header or headers method:
Response<String> resp = Requests.get(url)
// add one header
.addHeader("key1", "value1")
.addHeader("key2", "value2")
.text();
// set multi headers by map
Map<String, Object> headers = new HashMap<>();
headers.put("k1", "v1");
headers.put("k2", "v2");
Response<String> resp = Requests.get(url).headers(headers).text();
// set multi headers
Response<String> resp = Requests.get(url).headers(new Header(...), new Header(...))
.text();##Cookies Cookies can be add by:
Response<String> resp = Requests.get(url)
// add one cookie
.addCookie("key1", "value1")
.addCookie("key2", "value2")
.text();
Map<String, Object> cookies = new HashMap<>();
cookies.put("k1", "v1");
cookies.put("k2", "v2");
// set cookies by map
Response<String> resp = Requests.get(url).cookies(cookies).text();
// set cookies
Response<String> resp = Requests.get(url).cookies(new Cookie(...), new Cookie(...))
.text();##Request with data Http Post, Put, Patch method can send request body. Take Post for example:
// add post from data
Response<String> resp = Requests.post(url)
.addForm("key1", "value1").addForm("key2", "value2").text();
// set post form data
Response<String> resp = Requests.post(url).forms(new Parameter(...), new Parameter(...))
.text();
// set post form data by map
Map<String, Object> formData = new HashMap<>();
formData.put("k1", "v1");
formData.put("k2", "v2");
Response<String> resp = Requests.post(url).forms(formData).text();
// send byte array data as body
byte[] data = ...;
resp = Requests.post(url).data(data).text();
// send string data as body
String str = ...;
resp = Requests.post(url).data(str).text();
// send data from inputStream
InputStream in = ...
resp = Requests.post(url).data(in).text();One more complicate situation is multiPart post request, this can be done via multiPart method:
// send form-encoded data
InputStream in = ...;
byte[] bytes = ...;
Response<String> resp = Requests.post(url)
.addMultiPart("test", "value")
.addMultiPart("byFile", new File("/path/to/file"))
.addMultiPart("byStream", mimeType, in)
.addMultiPart("byBytes", mimeType, bytes)
.text();##Basic Auth Set http basic auth param by auth method:
Response<String> resp = Requests.get(url).auth("user", "passwd").verify(false).text();Use Client to reuse http connections, and custom connection properties. Client has similar method as Requests class.
There are two kinds of client, single and pooled.Single Client is not thread-safe and only use on http connection, can be use in single thread context;Pooled client is thread-safe and can be used across multi thread.
Note: you need to close client when no longer used.
try(Client client = Client.pooled()
.maxPerRoute(20) // max connection per site
.maxTotal(100) // max connectoin
.build()) {
Response<String> resp1 = client.get(url1).text();
Response<String> resp2 = client.get(url2).text();
// get session
Session session = client.session();
Response<String> response = session.get(url3).text();
}##Redirection Requests and Client will handle 30x http redirect automatically, you can get redirect history via:
Response<String> resp = client.get(url).text();
List<URI> history = resp.getHistory();Or you can disable it:
try (Client client = Client.single().allowRedirects(false).build()) {
Response<String> resp = client.get(url).text();
}There are two timeout parameters you can set, connect timeout, and socket timeout. The timeout value default to 10_1000 milliseconds.
// both connec timeout, and socket timeout
Client client = Client.single().timeout(30_000).build();
// set connect timeout and socket timeout separately
Client client = Client.single().socketTimeout(20_000).connectTimeout(30_000).build();You may not need to know, but Requests also use connect timeout as the timeout value get connection from connection pool if connection pool is used. ##Response compress Requests send Accept-Encoding: gzip, deflate, and handle gzipped response in default. You can disable this by:
Client client = Client.single().compress(false).build();##Https Verification Some https sites do not have trusted http certificate, Exception will be throwed when request. You can disable https certificate verify by:
Client client = Client.single().verify(false).build();##Proxy Set proxy by proxy method:
Client client = Client.single()
.proxy(Proxy.httpProxy("127.0.0.1", 8080))
.build();The proxy can be created by:
//http proxy
Proxy.httpProxy("127.0.0.1", 8080)
//https proxy
Proxy.httpsProxy("127.0.0.1", 8080)
//socket proxy
Proxy.socketProxy("127.0.0.1", 5678)
//with auth
Proxy.httpProxy("127.0.0.1", 8080, userName, password)Session keep cookies and basic auto cache and other http context for you, useful when need login or other situations. Session have the same usage as Requests and Client.
Session session = client.session();
Response<String> resp1 = session.get(url1).text();
Response<String> resp2 = session.get(url2).text();#Exceptions Requests wrapped all checked exceptions into one runtime exception: RequestException. Catch this if you mind. Unchecked Exceptions are leaved as it is.
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