winterwell.jtwitter
Class URLConnectionHttpClient

java.lang.Object
  winterwell.jtwitter.URLConnectionHttpClient

All Implemented Interfaces:

java.io.Serializable, Twitter.IHttpClient

Direct Known Subclasses:

OAuthSignpostClient

public class URLConnectionHttpClient
extends java.lang.Object
implements Twitter.IHttpClient, java.io.Serializable

A simple http client that uses the built in URLConnection class.

Provides Twitter-focused error-handling, generating the right TwitterException. Also has a retry-on-error mode which can help smooth out Twitter's sometimes intermittent service. See setRetryOnError(boolean).

See Also:

Serialized Form

Field Summary

protected java.lang.String	name
protected int	timeout

Constructor Summary

URLConnectionHttpClient()

URLConnectionHttpClient(java.lang.String name, java.lang.String password)

Method Summary

boolean	canAuthenticate() Whether this client is setup to do authentication when contacting the Twitter server.
protected static void	close(java.io.Closeable input) Close a reader/writer/stream, ignoring any exceptions that result.
java.net.HttpURLConnection	connect(java.lang.String url, java.util.Map<java.lang.String,java.lang.String> vars, boolean authenticate) Lower-level GET method.
Twitter.IHttpClient	copy()
protected void	disconnect(java.net.HttpURLConnection connection)
java.lang.String	getHeader(java.lang.String headerName) Fetch a header from the last http request.
java.lang.String	getPage(java.lang.String url, java.util.Map<java.lang.String,java.lang.String> vars, boolean authenticate) Send an HTTP GET request and return the response body.
RateLimit	getRateLimit(Twitter.KRequestType reqType)
java.lang.String	post(java.lang.String uri, java.util.Map<java.lang.String,java.lang.String> vars, boolean authenticate) Send an HTTP POST request and return the response body.
java.net.HttpURLConnection	post2_connect(java.lang.String uri, java.util.Map<java.lang.String,java.lang.String> vars) Lower-level POST method.
protected java.lang.String	post2_getPayload(java.util.Map<java.lang.String,java.lang.String> vars)
java.lang.String	postMultipartForm(java.lang.String url, java.util.Map<java.lang.String,?> vars)
protected void	processHeaders(java.net.HttpURLConnection connection) Cache headers for getHeader(String)
protected void	setAuthentication(java.net.URLConnection connection, java.lang.String name, java.lang.String password) Set a header for basic authentication login.
void	setHtmlImpliesError(boolean htmlImpliesError)
void	setMinRateLimit(int minRateLimit) Use this to protect your Twitter API rate-limit.
void	setRetryOnError(boolean retryOnError) False by default.
void	setTimeout(int millisecs) Set the timeout for a single get/post request.
java.lang.String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

name

protected java.lang.String name

timeout

protected int timeout

Constructor Detail

URLConnectionHttpClient

public URLConnectionHttpClient()

URLConnectionHttpClient

public URLConnectionHttpClient(java.lang.String name,
                               java.lang.String password)

Method Detail

close

protected static void close(java.io.Closeable input)

Close a reader/writer/stream, ignoring any exceptions that result. Also flushes if there is a flush() method.

Parameters:

input - Can be null

setHtmlImpliesError

public void setHtmlImpliesError(boolean htmlImpliesError)

Parameters:

htmlImpliesError - default is true. If true, an html response will be treated as a server error & generate a TwitterException.E50X

canAuthenticate

public boolean canAuthenticate()

Description copied from interface: Twitter.IHttpClient

Whether this client is setup to do authentication when contacting the Twitter server. Note: This is a fast method that does not call the server, so it does not check whether the access token or password is valid. See {Twitter#isValidLogin()} or Twitter_Account.verifyCredentials() if you need to check a login.

Specified by:

canAuthenticate in interface Twitter.IHttpClient

connect

public java.net.HttpURLConnection connect(java.lang.String url,
                                          java.util.Map<java.lang.String,java.lang.String> vars,
                                          boolean authenticate)
                                   throws java.io.IOException

Description copied from interface: Twitter.IHttpClient

Lower-level GET method.

Specified by:

connect in interface Twitter.IHttpClient

Returns:

Throws:

java.io.IOException

copy

public Twitter.IHttpClient copy()

Specified by:

copy in interface Twitter.IHttpClient

Returns:

a copy of this client. The copy can share structure, but it MUST be safe for passing to a new thread to be used in parallel with the original.

disconnect

protected final void disconnect(java.net.HttpURLConnection connection)

getHeader

public java.lang.String getHeader(java.lang.String headerName)

Description copied from interface: Twitter.IHttpClient

Fetch a header from the last http request. This is inherently NOT thread safe. Headers from error messages should (probably) be cached.

Specified by:

getHeader in interface Twitter.IHttpClient

Returns:

header value, or null if unset

getPage

public final java.lang.String getPage(java.lang.String url,
                                      java.util.Map<java.lang.String,java.lang.String> vars,
                                      boolean authenticate)
                               throws TwitterException

Description copied from interface: Twitter.IHttpClient

Send an HTTP GET request and return the response body. Note that this will change all line breaks into system line breaks!

Specified by:

getPage in interface Twitter.IHttpClient

Parameters:

url - The uri to fetch

vars - get arguments to add to the uri

authenticate - If true, use authentication. The authentication method used depends on the implementation (basic-auth, OAuth). It is an error to use true if no authentication details have been set.

Throws:

TwitterException - for a variety of reasons

TwitterException.E404 - for resource-does-not-exist errors

getRateLimit

public RateLimit getRateLimit(Twitter.KRequestType reqType)

Specified by:

getRateLimit in interface Twitter.IHttpClient

See Also:

This is where the Twitter method is implemented.

postMultipartForm

public final java.lang.String postMultipartForm(java.lang.String url,
                                                java.util.Map<java.lang.String,?> vars)
                                         throws TwitterException

Parameters:

uri -

vars - Can include File values

Returns:

Throws:

TwitterException

post

public final java.lang.String post(java.lang.String uri,
                                   java.util.Map<java.lang.String,java.lang.String> vars,
                                   boolean authenticate)
                            throws TwitterException

Description copied from interface: Twitter.IHttpClient

Send an HTTP POST request and return the response body.

Specified by:

post in interface Twitter.IHttpClient

Parameters:

uri - The uri to post to.

vars - The form variables to send. These are URL encoded before sending.

authenticate - If true, send user authentication

Returns:

The response from the server.

Throws:

TwitterException - for a variety of reasons

TwitterException.E404 - for resource-does-not-exist errors

post2_connect

public java.net.HttpURLConnection post2_connect(java.lang.String uri,
                                                java.util.Map<java.lang.String,java.lang.String> vars)
                                         throws java.lang.Exception

Description copied from interface: Twitter.IHttpClient

Lower-level POST method.

Specified by:

post2_connect in interface Twitter.IHttpClient

Returns:

a freshly opened authorised connection

Throws:

TwitterException

java.lang.Exception

post2_getPayload

protected java.lang.String post2_getPayload(java.util.Map<java.lang.String,java.lang.String> vars)

processHeaders

protected final void processHeaders(java.net.HttpURLConnection connection)

Cache headers for getHeader(String)

Parameters:

connection -

setAuthentication

protected void setAuthentication(java.net.URLConnection connection,
                                 java.lang.String name,
                                 java.lang.String password)

Set a header for basic authentication login.

setMinRateLimit

public void setMinRateLimit(int minRateLimit)

Use this to protect your Twitter API rate-limit. E.g. if you want to keep some credit in reserve for core activity. 0 by default. If set above zero, this JTwitter object will start pre-emptively throwing rate-limit exceptions when it gets down to the specified level.

setRetryOnError

public void setRetryOnError(boolean retryOnError)

False by default. Setting this to true switches on a robustness workaround: when presented with a 50X server error, the system will wait 1/2 a second and make a second attempt.

setTimeout

public void setTimeout(int millisecs)

Description copied from interface: Twitter.IHttpClient

Set the timeout for a single get/post request. This is an optional method - implementations can ignore it!

Specified by:

setTimeout in interface Twitter.IHttpClient

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object