httpconnection.java

用于移动设备上的java虚拟机源代码

     * 500: The server encountered an unexpected condition which prevented it
     *	from fulfilling the request.
     */
    public static final int HTTP_INTERNAL_ERROR = 500;

    /**
     * 501: The server does not support the functionality required to
     * fulfill the request.
     */
    public static final int HTTP_NOT_IMPLEMENTED = 501;

    /**
     * 502: The server, while acting as a gateway or proxy, received an invalid
     *   response from the upstream server it accessed in attempting to
     *   fulfill the request.
     */
    public static final int HTTP_BAD_GATEWAY = 502;

    /**
     * 503: The server is currently unable to handle the request due to a
     *   temporary overloading or maintenance of the server.
     */
    public static final int HTTP_UNAVAILABLE = 503;

    /**
     * 504: The server, while acting as a gateway or proxy, did not receive a
     *   timely response from the upstream server specified by the URI
     *   or some other auxiliary server it needed
     *   to access in attempting to complete the request.
     */
    public static final int HTTP_GATEWAY_TIMEOUT = 504;

    /**
     * 505: The server does not support, or refuses to support, the HTTP
     *  protocol version that was used in the request message.
     */
    public static final int HTTP_VERSION = 505;

    /**
     * Return a string representation of the URL for this connection.
     *
     * @return the string representation of the URL for this connection.
     */
    public String getURL();

    /**
     * Returns the protocol name of the URL of this
     * <code>HttpConnection</code>. e.g., http or https
     *
     * @return  the protocol of the URL of this <code>HttpConnection</code>.
     */
    public String getProtocol();

    /**
     * Returns the host information of the URL of
     * this <code>HttpConnection</code>. e.g. host name or IPv4 address
     *
     * @return  the host information of the URL of
     * this <code>HttpConnection</code>.
     */
    public String getHost();

    /**
     * Returns the file portion of the URL of this <code>HttpConnection</code>.
     *
     * @return  the file portion of the URL of this <code>HttpConnection</code>.
     * <code>null</code> is returned if there is no file.
     */
    public String getFile();

    /**
     * Returns the ref portion of the URL of this <code>HttpConnection</code>.
     * RFC2396 specifies the optional fragment identifier as the
     * the text after the crosshatch (#) character in the URL.
     * This information  may be used by the user agent as additional
     * reference information after the resource is successfully retrieved.
     * The format and interpretation of the fragment identifier is dependent
     * on the media type[RFC2046] of the retrieved information.
     *
     * @return  the ref portion of the URL of this <code>HttpConnection</code>.
     * <code>null</code> is returned if there is no value.
     */
    public String getRef();

    /**
     * Returns the query portion of the URL of this
     * <code>HttpConnection</code>.
     *
     * RFC2396 defines the query component as the text after the first
     * question-mark (?)  character in the URL.
     *
     * @return  the query portion of the URL of this
     *  <code>HttpConnection</code>.
     * <code>null</code> is returned if there is no value.  */
    public String getQuery();

    /**
     * Returns the network port number of the URL for this
     * <code>HttpConnection</code>.
     *
     * @return  the network port number of the URL for this
     * <code>HttpConnection</code>.
     * The default HTTP port number (80) is returned if there was
     * no port number in the string passed to <code>Connector.open</code>.
     */
    public int getPort();

    /**
     * Get the current request method. e.g. HEAD, GET, POST
     * The default value is GET.
     * @return the HTTP request method
     * @see #setRequestMethod
     */
    public String getRequestMethod();

    /**
     * Set the method for the URL request, one of:
     * <UL>
     *  <LI>GET
     *  <LI>POST
     *  <LI>HEAD
     * </UL> are legal, subject to protocol restrictions.  The default
     * method is GET.
     *
     * @param method the HTTP method
     * @exception IOException if the method cannot be reset or if
     *              the requested method isn't valid for HTTP.
     * @see #getRequestMethod
     */
    public void setRequestMethod(String method) throws IOException;

    /**
     * Returns the value of the named general request property for this
     * connection.
     *
     * @param key the keyword by which the request property is
     *  known (e.g., "accept").
     * @return  the value of the named general request property for this
     *           connection. If there is no key with the specified name then
     *		<CODE>null</CODE> is returned.
     * @see #setRequestProperty
     */
    public String getRequestProperty(String key);

    /**
     * Sets the general request property. If a property with the key already
     * exists, overwrite its value with the new value.
     *
     * <p> <strong>Note:</strong> HTTP requires all request properties
     * which can legally have multiple instances with the same key
     * to use a comma-separated list syntax which enables multiple
     * properties to be appended into a single property.
     *
     * @param   key     the keyword by which the request is known
     *                  (e.g., "<code>accept</code>").
     * @param   value   the value associated with it.
     * @exception IOException is thrown if the connection is in the
     *  connected state.
     * @see #getRequestProperty
     */
    public void setRequestProperty(String key, String value) throws IOException;

    /**
     * Returns the HTTP response status code.
     * It parses responses like:
     * <PRE>
     * HTTP/1.0 200 OK
     * HTTP/1.0 401 Unauthorized
     * </PRE>
     * and extracts the ints 200 and 401 respectively.
     * from the response (i.e., the response is not valid HTTP).
     * @exception IOException if an error occurred connecting to the server.
     * @return the HTTP Status-Code or -1 if no status code can be discerned.
     */
    public int getResponseCode() throws IOException;

    /**
     * Gets the HTTP response message, if any, returned along with the
     * response code from a server.  From responses like:
     * <PRE>
     * HTTP/1.0 200 OK
     * HTTP/1.0 404 Not Found
     * </PRE>
     * Extracts the Strings "OK" and "Not Found" respectively.
     * Returns null if none could be discerned from the responses
     * (the result was not valid HTTP).
     * @exception IOException if an error occurred connecting to the server.
     * @return the HTTP response message, or <code>null</code>
     */
    public String getResponseMessage() throws IOException;

    /**
     * Returns the value of the <code>expires</code> header field.
     *
     * @return  the expiration date of the resource that this URL references,
     *          or 0 if not known. The value is the number of milliseconds
     *          since January 1, 1970 GMT.
     * @exception IOException if an error occurred connecting to the server.
     */
    public long getExpiration() throws IOException;

    /**
     * Returns the value of the <code>date</code> header field.
     *
     * @return  the sending date of the resource that the URL references,
     *          or <code>0</code> if not known. The value returned is the
     *          number of milliseconds since January 1, 1970 GMT.
     * @exception IOException if an error occurred connecting to the server.
     */
    public long getDate() throws IOException;

    /**
     * Returns the value of the <code>last-modified</code> header field.
     * The result is the number of milliseconds since January 1, 1970 GMT.
     *
     * @return  the date the resource referenced by this
     *          <code>HttpConnection</code> was last modified, or
     *  0 if not known.
     * @exception IOException if an error occurred connecting to the server.
     */
    public long getLastModified() throws IOException;

    /**
     * Returns the value of the named header field.
     *
     * @param   name of a header field.
     * @return  the value of the named header field, or <code>null</code>
     *          if there is no such field in the header.
     * @exception IOException if an error occurred connecting to the server.
     */
    public String getHeaderField(String name) throws IOException;

    /**
     * Returns the value of the named field parsed as a number.
     * <p>
     * This form of <code>getHeaderField</code> exists because some
     * connection types (e.g., <code>http-ng</code>) have pre-parsed
     * headers. Classes for that connection type can override this method
     * and short-circuit the parsing.
     *
     * @param   name      the name of the header field.
     * @param   def   the default value.
     * @return  the value of the named field, parsed as an integer. The
     *          <code>def</code> value is returned if the field is
     *          missing or malformed.
     * @exception IOException if an error occurred connecting to the server.
     */
    public int getHeaderFieldInt(String name, int def) throws IOException;

    /**
     * Returns the value of the named field parsed as date.
     * The result is the number of milliseconds since January 1, 1970 GMT
     * represented by the named field.
     * <p>
     * This form of <code>getHeaderField</code> exists because some
     * connection types (e.g., <code>http-ng</code>) have pre-parsed
     * headers. Classes for that connection type can override this method
     * and short-circuit the parsing.
     *
     * @param   name     the name of the header field.
     * @param   def   a default value.
     * @return  the value of the field, parsed as a date. The value of the
     *          <code>def</code> argument is returned if the field is
     *          missing or malformed.
     * @exception IOException if an error occurred connecting to the server.
     */
    public long getHeaderFieldDate(String name, long def) throws IOException;


    /**
     * Gets a header field value by index.
     *
     * @return the value of the  nth  header field or
     * <code>null</code> if the array index is out of range.
     * An empty String is returned if the field does not have a value.
     * @param n the index of the header field
     * @exception IOException if an error occurred connecting to the server.
     */
    public String getHeaderField(int n) throws IOException;

    /**
     * Gets a header field key by index.
     *
     * @return the key of the nth header field or
     *  <code>null</code> if the array index is out of range.
     * @param n the index of the header field
     * @exception IOException if an error occurred connecting to the server.
     */
    public String getHeaderFieldKey(int n) throws IOException;

}