Java in a Nutshell, 5th Edition [Electronic resources]

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HttpURLConnectionjava.net

Java 1.1

This class is a specialization of URLConnection. An instance of this class is returned when the openConnection( ) method is called for a URL object that uses the HTTP protocol. The many constants defined by this class are the status codes returned by HTTP servers. setRequestMethod( ) specifies what kind of HTTP request is made. The contents of this request must be sent through the OutputStream returned by the getOutputStream( ) method of the superclass. Once an HTTP request has been sent, getresponseCode( ) returns the HTTP server's response code as an integer, and geTResponseMessage( ) returns the server's response message. The disconnect( ) method closes the connection. The static setFollowRedirects( ) specifies whether URL connections that use the HTTP protocol should automatically follow redirect responses sent by HTTP servers. In order to successfully use this class, you need to understand the details of the HTTP protocol.

Figure 12-5. java.net.HttpURLConnection

public abstract class

HttpURLConnection extends URLConnection { // Protected Constructors protected

HttpURLConnection (URL

u ); // Public Constants public static final int

HTTP_ACCEPTED ; =202 public static final int

HTTP_BAD_GATEWAY ; =502 public static final int

HTTP_BAD_METHOD ; =405 public static final int

HTTP_BAD_REQUEST ; =400 public static final int

HTTP_CLIENT_TIMEOUT ; =408 public static final int

HTTP_CONFLICT ; =409 public static final int

HTTP_CREATED ; =201 public static final int

HTTP_ENTITY_TOO_LARGE ; =413 public static final int

HTTP_FORBIDDEN ; =403 public static final int

HTTP_GATEWAY_TIMEOUT ; =504 public static final int

HTTP_GONE ; =410 public static final int

HTTP_INTERNAL_ERROR ; =500 public static final int

HTTP_LENGTH_REQUIRED ; =411 public static final int

HTTP_MOVED_PERM ; =301 public static final int

HTTP_MOVED_TEMP ; =302 public static final int

HTTP_MULT_CHOICE ; =300 public static final int

HTTP_NO_CONTENT ; =204 public static final int

HTTP_NOT_ACCEPTABLE ; =406 public static final int

HTTP_NOT_AUTHORITATIVE ; =203 public static final int

HTTP_NOT_FOUND ; =404

1.3 public static final int

HTTP_NOT_IMPLEMENTED ; =501 public static final int

HTTP_NOT_MODIFIED ; =304 public static final int

HTTP_OK ; =200 public static final int

HTTP_PARTIAL ; =206 public static final int

HTTP_PAYMENT_REQUIRED ; =402 public static final int

HTTP_PRECON_FAILED ; =412 public static final int

HTTP_PROXY_AUTH ; =407 public static final int

HTTP_REQ_TOO_LONG ; =414 public static final int

HTTP_RESET ; =205 public static final int

HTTP_SEE_OTHER ; =303 public static final int

HTTP_UNAUTHORIZED ; =401 public static final int

HTTP_UNAVAILABLE ; =503 public static final int

HTTP_UNSUPPORTED_TYPE ; =415 public static final int

HTTP_USE_PROXY ; =305 public static final int

HTTP_VERSION ; =505 // Public Class Methods public static boolean

getFollowRedirects ( ); public static void

setFollowRedirects (boolean

set ); // Public Instance Methods public abstract void

disconnect ( );

1.2 public java.io.InputStream

getErrorStream ( ); constant

1.3 public boolean

getInstanceFollowRedirects ( ); public String

getRequestMethod ( ); public int

getResponseCode ( ) throws java.io.IOException; public String

getResponseMessage ( ) throws java.io.IOException;

5.0 public void

setChunkedStreamingMode (int

chunklen );

5.0 public void

setFixedLengthStreamingMode (int

contentLength );

1.3 public void

setInstanceFollowRedirects (boolean

followRedirects ); public void

setRequestMethod (String

method ) throws ProtocolException; public abstract boolean

usingProxy ( ); // Public Methods Overriding URLConnection

1.4 public String

getHeaderField (int

n ); constant

1.3 public long

getHeaderFieldDate (String

name , long

Default );

1.4 public String

getHeaderFieldKey (int

n ); constant

1.2 public java.security.Permission

getPermission ( ) throws java.io.IOException; // Protected Instance Fields

5.0 protected int

chunkLength ;

5.0 protected int

fixedContentLength ;

1.3 protected boolean

instanceFollowRedirects ; protected String

method ; protected int

responseCode ; protected String

responseMessage ; // Deprecated Public Fields

# public static final int

HTTP_SERVER_ERROR ; =500 }

Subclasses

javax.net.ssl.HttpsURLConnection