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HTTPClient
Class HTTPResponse

java.lang.Object
  |
  +--HTTPClient.HTTPResponse
public class HTTPResponse
extends Object
implements HTTPClientModuleConstants

This defines the http-response class returned by the requests. It's basically a wrapper around the Response class which first lets all the modules handle the response before finally giving the info to the user.

Since:
0.3
Version:
0.3-3 06/05/2001
Author:
Ronald Tschalär

Fields inherited from interface HTTPClient.HTTPClientModuleConstants
REQ_CONTINUE, REQ_NEWCON_RST, REQ_NEWCON_SND, REQ_RESPONSE, REQ_RESTART, REQ_RETURN, REQ_SHORTCIRC, RSP_CONTINUE, RSP_NEWCON_REQ, RSP_NEWCON_SND, RSP_REQUEST, RSP_RESTART, RSP_SEND, RSP_SHORTCIRC
 
Method Summary
 byte[] getData()
          Reads all the response data into a byte array.
 URI getEffectiveURI()
          Get the final URI of the document.
 URL getEffectiveURL()
          Deprecated. use getEffectiveURI() instead
 String getHeader(String hdr)
          Retrieves the value for a given header.
 Date getHeaderAsDate(String hdr)
          Retrieves the value for a given header.
 int getHeaderAsInt(String hdr)
          Retrieves the value for a given header.
 InputStream getInputStream()
          Gets an input stream from which the returned data can be read.
 URI getOriginalURI()
          Get the original URI used in the request.
 String getReasonLine()
          Give the reason line associated with the status code.
 String getServer()
          Deprecated. This method is a remnant of V0.1; use getHeader("Server") instead.
 int getStatusCode()
          Give the status code for this request.
 String getText()
          Reads all the response data into a buffer and turns it into a string using the appropriate character converter.
 String getTrailer(String trailer)
          Retrieves the value for a given trailer.
 Date getTrailerAsDate(String trailer)
          Retrieves the value for a given trailer.
 int getTrailerAsInt(String trailer)
          Retrieves the value for a given tailer.
 String getVersion()
          Get the HTTP version used for the response.
 Enumeration listHeaders()
          Returns an enumeration of all the headers available via getHeader().
 Enumeration listTrailers()
          Returns an enumeration of all the trailers available via getTrailer().
 boolean retryRequest()
          Should the request be retried by the application? If the application used an HttpOutputStream in the request then various modules (such as the redirection and authorization modules) are not able to resend the request themselves.
 String toString()
          produces a full list of headers and their values, one per line.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Method Detail

getStatusCode

public final int getStatusCode()
                        throws IOException,
                               ModuleException
Give the status code for this request. These are grouped as follows:
Throws:
IOException - if any exception occurs on the socket.
ModuleException - if any module encounters an exception.

getReasonLine

public final String getReasonLine()
                           throws IOException,
                                  ModuleException
Give the reason line associated with the status code.
Throws:
IOException - If any exception occurs on the socket.
ModuleException - if any module encounters an exception.

getVersion

public final String getVersion()
                        throws IOException,
                               ModuleException
Get the HTTP version used for the response.
Throws:
IOException - If any exception occurs on the socket.
ModuleException - if any module encounters an exception.

getServer

public final String getServer()
                       throws IOException,
                              ModuleException
Deprecated. This method is a remnant of V0.1; use getHeader("Server") instead.

Get the name and type of server.
Throws:
IOException - If any exception occurs on the socket.
ModuleException - if any module encounters an exception.
See Also:
getHeader(java.lang.String)

getOriginalURI

public final URI getOriginalURI()
Get the original URI used in the request.
Returns:
the URI used in primary request

getEffectiveURL

public final URL getEffectiveURL()
                          throws IOException,
                                 ModuleException
Deprecated. use getEffectiveURI() instead

Get the final URL of the document. This is set if the original request was deferred via the "moved" (301, 302, or 303) return status.
Returns:
the effective URL, or null if no redirection occured
Throws:
IOException - If any exception occurs on the socket.
ModuleException - if any module encounters an exception.
See Also:
getEffectiveURI()

getEffectiveURI

public final URI getEffectiveURI()
                          throws IOException,
                                 ModuleException
Get the final URI of the document. If the request was redirected via the "moved" (301, 302, 303, or 307) return status this returns the URI used in the last redirection; otherwise it returns the original URI.
Returns:
the effective URI
Throws:
IOException - If any exception occurs on the socket.
ModuleException - if any module encounters an exception.

getHeader

public String getHeader(String hdr)
                 throws IOException,
                        ModuleException
Retrieves the value for a given header.
Parameters:
hdr - the header name.
Returns:
the value for the header, or null if non-existent.
Throws:
IOException - If any exception occurs on the socket.
ModuleException - if any module encounters an exception.

getHeaderAsInt

public int getHeaderAsInt(String hdr)
                   throws IOException,
                          ModuleException,
                          NumberFormatException
Retrieves the value for a given header. The value is parsed as an int.
Parameters:
hdr - the header name.
Returns:
the value for the header if the header exists
Throws:
NumberFormatException - if the header's value is not a number or if the header does not exist.
IOException - if any exception occurs on the socket.
ModuleException - if any module encounters an exception.

getHeaderAsDate

public Date getHeaderAsDate(String hdr)
                     throws IOException,
                            IllegalArgumentException,
                            ModuleException
Retrieves the value for a given header. The value is parsed as a date; if this fails it is parsed as a long representing the number of seconds since 12:00 AM, Jan 1st, 1970. If this also fails an exception is thrown.
Note: When sending dates use Util.httpDate().
Parameters:
hdr - the header name.
Returns:
the value for the header, or null if non-existent.
Throws:
IllegalArgumentException - if the header's value is neither a legal date nor a number.
IOException - if any exception occurs on the socket.
ModuleException - if any module encounters an exception.

listHeaders

public Enumeration listHeaders()
                        throws IOException,
                               ModuleException
Returns an enumeration of all the headers available via getHeader().
Throws:
IOException - If any exception occurs on the socket.
ModuleException - if any module encounters an exception.

getTrailer

public String getTrailer(String trailer)
                  throws IOException,
                         ModuleException
Retrieves the value for a given trailer. This should not be invoked until all response data has been read. If invoked before it will call getData() to force the data to be read.
Parameters:
trailer - the trailer name.
Returns:
the value for the trailer, or null if non-existent.
Throws:
IOException - If any exception occurs on the socket.
ModuleException - if any module encounters an exception.
See Also:
getData()

getTrailerAsInt

public int getTrailerAsInt(String trailer)
                    throws IOException,
                           ModuleException,
                           NumberFormatException
Retrieves the value for a given tailer. The value is parsed as an int.
Parameters:
trailer - the tailer name.
Returns:
the value for the trailer if the trailer exists
Throws:
NumberFormatException - if the trailer's value is not a number or if the trailer does not exist.
IOException - if any exception occurs on the socket.
ModuleException - if any module encounters an exception.

getTrailerAsDate

public Date getTrailerAsDate(String trailer)
                      throws IOException,
                             IllegalArgumentException,
                             ModuleException
Retrieves the value for a given trailer. The value is parsed as a date; if this fails it is parsed as a long representing the number of seconds since 12:00 AM, Jan 1st, 1970. If this also fails an IllegalArgumentException is thrown.
Note: When sending dates use Util.httpDate().
Parameters:
trailer - the trailer name.
Returns:
the value for the trailer, or null if non-existent.
Throws:
IllegalArgumentException - if the trailer's value is neither a legal date nor a number.
IOException - if any exception occurs on the socket.
ModuleException - if any module encounters an exception.

listTrailers

public Enumeration listTrailers()
                         throws IOException,
                                ModuleException
Returns an enumeration of all the trailers available via getTrailer().
Throws:
IOException - If any exception occurs on the socket.
ModuleException - if any module encounters an exception.

getData

public byte[] getData()
               throws IOException,
                      ModuleException
Reads all the response data into a byte array. Note that this method won't return until all the data has been received (so for instance don't invoke this method if the server is doing a server push). If getInputStream() had been previously invoked then this method only returns any unread data remaining on the stream and then closes it.

Note to the unwary: code like 

     System.out.println("The data: " + resp.getData())
will probably not do what you want - use 
     System.out.println("The data: " + resp.getText())
instead.
Returns:
an array containing the data (body) returned. If no data was returned then it's set to a zero-length array.
Throws:
IOException - If any io exception occured while reading the data
ModuleException - if any module encounters an exception.
See Also:
getInputStream()

getText

public String getText()
               throws IOException,
                      ModuleException,
                      ParseException
Reads all the response data into a buffer and turns it into a string using the appropriate character converter. Since this uses getData(), the caveats of that method apply here as well.
Returns:
the body as a String. If no data was returned then an empty string is returned.
Throws:
IOException - If any io exception occured while reading the data, or if the content is not text
ModuleException - if any module encounters an exception.
ParseException - if an error occured trying to parse the content-type header field
See Also:
getData()

getInputStream

public InputStream getInputStream()
                           throws IOException,
                                  ModuleException
Gets an input stream from which the returned data can be read. Note that if getData() had been previously invoked it will actually return a ByteArrayInputStream created from that data.
Returns:
the InputStream.
Throws:
IOException - If any exception occurs on the socket.
ModuleException - if any module encounters an exception.
See Also:
getData()

retryRequest

public boolean retryRequest()
                     throws IOException,
                            ModuleException
Should the request be retried by the application? If the application used an HttpOutputStream in the request then various modules (such as the redirection and authorization modules) are not able to resend the request themselves. Instead, it becomes the application's responsibility. The application can check this flag, and if it's set, resend the exact same request. The modules such as the RedirectionModule or AuthorizationModule will then recognize the resend and fix up or redirect the request as required (i.e. they defer their normal action until the resend).

If the application resends the request then it must use the same HttpOutputStream instance. This is because the modules use this to recognize the retried request and to perform the necessary work on the request before it's sent.

Here is a skeleton example of usage: 

     OutputStream out = new HttpOutputStream(1234);
     do
     {
         rsp = con.Post("/cgi-bin/my_cgi", out);
         out.write(...);
         out.close();
     } while (rsp.retryRequest());

     if (rsp.getStatusCode() >= 300)
         ...

Note that for this to ever return true, the java system property HTTPClient.deferStreamed must be set to true at the beginning of the application (before the HTTPConnection class is loaded). This prevents unwary applications from causing inadvertent memory leaks. If an application does set this, then it must resend any request whose response returns true here in order to prevent memory leaks (a switch to JDK 1.2 will allow us to use weak references and eliminate this problem).

Returns:
true if the request should be retried.
Throws:
IOException - If any exception occurs on the socket.
ModuleException - if any module encounters an exception.

toString

public String toString()
produces a full list of headers and their values, one per line.
Overrides:
toString in class Object
Returns:
a string containing the headers
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