java.net
Class HttpURLConnection

java.lang.Object
  |
  +--java.net.URLConnection
        |
        +--java.net.HttpURLConnection

public abstract class HttpURLConnection

extends URLConnection

A URLConnection with support for HTTP-specific features. See the spec for details.

Since:

JDK1.1

Field Summary

static int	HTTP_ACCEPTED
static int	HTTP_BAD_GATEWAY
static int	HTTP_BAD_METHOD
static int	HTTP_BAD_REQUEST 4XX: client error
static int	HTTP_CLIENT_TIMEOUT
static int	HTTP_CONFLICT
static int	HTTP_CREATED
static int	HTTP_ENTITY_TOO_LARGE
static int	HTTP_FORBIDDEN
static int	HTTP_GATEWAY_TIMEOUT
static int	HTTP_GONE
static int	HTTP_INTERNAL_ERROR
static int	HTTP_LENGTH_REQUIRED
static int	HTTP_MOVED_PERM
static int	HTTP_MOVED_TEMP
static int	HTTP_MULT_CHOICE 3XX: relocation/redirect
static int	HTTP_NO_CONTENT
static int	HTTP_NOT_ACCEPTABLE
static int	HTTP_NOT_AUTHORITATIVE
static int	HTTP_NOT_FOUND
static int	HTTP_NOT_MODIFIED
static int	HTTP_OK 2XX: generally "OK"
static int	HTTP_PARTIAL
static int	HTTP_PAYMENT_REQUIRED
static int	HTTP_PRECON_FAILED
static int	HTTP_PROXY_AUTH
static int	HTTP_REQ_TOO_LONG
static int	HTTP_RESET
static int	HTTP_SEE_OTHER
static int	HTTP_SERVER_ERROR 5XX: server error
static int	HTTP_UNAUTHORIZED
static int	HTTP_UNAVAILABLE
static int	HTTP_UNSUPPORTED_TYPE
static int	HTTP_USE_PROXY
static int	HTTP_VERSION
protected String	method
protected int	responseCode
protected String	responseMessage

Fields inherited from class java.net.URLConnection

allowUserInteraction, connected, doInput, doOutput, ifModifiedSince, url, useCaches

Constructor Summary

protected

HttpURLConnection(URL u) Constructor for the URLStreamHandler.

Method Summary

abstract void	disconnect() Close the connection to the server.
InputStream	getErrorStream() Returns the error stream if the connection failed but the server sent useful data nonetheless.
static boolean	getFollowRedirects()
Permission	getPermission()
String	getRequestMethod() Get the request method.
int	getResponseCode() Gets HTTP response status.
String	getResponseMessage() Gets the HTTP response message, if any, returned along with the response code from a server.
static void	setFollowRedirects(boolean set) Sets whether HTTP redirects (requests with response code 3xx) should be automatically followed by this class.
void	setRequestMethod(String method) Set the method for the URL request, one of: GET POST HEAD OPTIONS PUT DELETE TRACE are legal, subject to protocol restrictions.
abstract boolean	usingProxy() Indicates if the connection is going through a proxy.

Methods inherited from class java.net.URLConnection

connect, getAllowUserInteraction, getContent, getContentEncoding, getContentLength, getContentType, getDate, getDefaultAllowUserInteraction, getDefaultRequestProperty, getDefaultUseCaches, getDoInput, getDoOutput, getExpiration, getFileNameMap, getHeaderField, getHeaderField, getHeaderFieldDate, getHeaderFieldInt, getHeaderFieldKey, getIfModifiedSince, getInputStream, getLastModified, getOutputStream, getRequestProperty, getURL, getUseCaches, guessContentTypeFromName, guessContentTypeFromStream, setAllowUserInteraction, setContentHandlerFactory, setDefaultAllowUserInteraction, setDefaultRequestProperty, setDefaultUseCaches, setDoInput, setDoOutput, setFileNameMap, setIfModifiedSince, setRequestProperty, setUseCaches, toString

Methods inherited from class java.lang.Object

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

Field Detail

method

protected String method

responseCode

protected int responseCode

responseMessage

protected String responseMessage

HTTP_OK

public static final int HTTP_OK

2XX: generally "OK"

HTTP_CREATED

public static final int HTTP_CREATED

HTTP_ACCEPTED

public static final int HTTP_ACCEPTED

HTTP_NOT_AUTHORITATIVE

public static final int HTTP_NOT_AUTHORITATIVE

HTTP_NO_CONTENT

public static final int HTTP_NO_CONTENT

HTTP_RESET

public static final int HTTP_RESET

HTTP_PARTIAL

public static final int HTTP_PARTIAL

HTTP_MULT_CHOICE

public static final int HTTP_MULT_CHOICE

3XX: relocation/redirect

HTTP_MOVED_PERM

public static final int HTTP_MOVED_PERM

HTTP_MOVED_TEMP

public static final int HTTP_MOVED_TEMP

HTTP_SEE_OTHER

public static final int HTTP_SEE_OTHER

HTTP_NOT_MODIFIED

public static final int HTTP_NOT_MODIFIED

HTTP_USE_PROXY

public static final int HTTP_USE_PROXY

HTTP_BAD_REQUEST

public static final int HTTP_BAD_REQUEST

4XX: client error

HTTP_UNAUTHORIZED

public static final int HTTP_UNAUTHORIZED

HTTP_PAYMENT_REQUIRED

public static final int HTTP_PAYMENT_REQUIRED

HTTP_FORBIDDEN

public static final int HTTP_FORBIDDEN

HTTP_NOT_FOUND

public static final int HTTP_NOT_FOUND

HTTP_BAD_METHOD

public static final int HTTP_BAD_METHOD

HTTP_NOT_ACCEPTABLE

public static final int HTTP_NOT_ACCEPTABLE

HTTP_PROXY_AUTH

public static final int HTTP_PROXY_AUTH

HTTP_CLIENT_TIMEOUT

public static final int HTTP_CLIENT_TIMEOUT

HTTP_CONFLICT

public static final int HTTP_CONFLICT

HTTP_GONE

public static final int HTTP_GONE

HTTP_LENGTH_REQUIRED

public static final int HTTP_LENGTH_REQUIRED

HTTP_PRECON_FAILED

public static final int HTTP_PRECON_FAILED

HTTP_ENTITY_TOO_LARGE

public static final int HTTP_ENTITY_TOO_LARGE

HTTP_REQ_TOO_LONG

public static final int HTTP_REQ_TOO_LONG

HTTP_UNSUPPORTED_TYPE

public static final int HTTP_UNSUPPORTED_TYPE

HTTP_SERVER_ERROR

public static final int HTTP_SERVER_ERROR

5XX: server error

HTTP_INTERNAL_ERROR

public static final int HTTP_INTERNAL_ERROR

HTTP_BAD_GATEWAY

public static final int HTTP_BAD_GATEWAY

HTTP_UNAVAILABLE

public static final int HTTP_UNAVAILABLE

HTTP_GATEWAY_TIMEOUT

public static final int HTTP_GATEWAY_TIMEOUT

HTTP_VERSION

public static final int HTTP_VERSION

Constructor Detail

HttpURLConnection

protected HttpURLConnection(URL u)

Constructor for the URLStreamHandler.

Method Detail

setFollowRedirects

public static void setFollowRedirects(boolean set)

Sets whether HTTP redirects (requests with response code 3xx) should be automatically followed by this class. True by default. Applets cannot change this variable.

If there is a security manager, this method first calls the security manager's checkSetFactory method to ensure the operation is allowed. This could result in a SecurityException.

Throws:

SecurityException - if a security manager exists and its checkSetFactory method doesn't allow the operation.

See Also:

SecurityManager.checkSetFactory()

getFollowRedirects

public static boolean getFollowRedirects()

setRequestMethod

public void setRequestMethod(String method)
                      throws ProtocolException

Set the method for the URL request, one of:

• GET
• POST
• HEAD
• OPTIONS
• PUT
• DELETE
• TRACE

are legal, subject to protocol restrictions. The default method is GET.

Throws:

ProtocolException - if the method cannot be reset or if the requested method isn't valid for HTTP.

getRequestMethod

public String getRequestMethod()

Get the request method.

getResponseCode

public int getResponseCode()
                    throws IOException

Gets HTTP response status. From responses like:

 HTTP/1.0 200 OK
 HTTP/1.0 401 Unauthorized
 

Extracts the ints 200 and 401 respectively. Returns -1 if none can be discerned from the response (i.e., the response is not valid HTTP).

Throws:

IOException - if an error occurred connecting to the server.

getResponseMessage

public String getResponseMessage()
                          throws IOException

Gets the HTTP response message, if any, returned along with the response code from a server. From responses like:

 HTTP/1.0 200 OK
 HTTP/1.0 404 Not Found
 

Extracts the Strings "OK" and "Not Found" respectively. Returns null if none could be discerned from the responses (the result was not valid HTTP).

Throws:

IOException - if an error occurred connecting to the server.

disconnect

public abstract void disconnect()

Close the connection to the server.

usingProxy

public abstract boolean usingProxy()

Indicates if the connection is going through a proxy.

getPermission

public Permission getPermission()
                         throws IOException

Overrides:

getPermission in class URLConnection

getErrorStream

public InputStream getErrorStream()

Returns the error stream if the connection failed but the server sent useful data nonetheless. The typical example is when an HTTP server responds with a 404, which will cause a FileNotFoundException to be thrown in connect, but the server sent an HTML help page with suggestions as to what to do.

This method will not cause a connection to be initiated. If there the connection was not connected, or if the server did not have an error while connecting or if the server did have an error but there no error data was sent, this method will return null. This is the default.

Returns:

an error stream if any, null if there have been no errors, the connection is not connected or the server sent no useful data.