- All Implemented Interfaces:
Request
,AutoCloseable
- Direct Known Subclasses:
HttpsExchange
The typical life-cycle of a HttpExchange
is shown in the sequence
below:
getRequestMethod()
to determine the command.getRequestHeaders()
to examine the request headers (if needed).getRequestBody()
returns anInputStream
for reading the request body. After reading the request body, the stream should be closed.getResponseHeaders()
to set any response headers, except content-length.sendResponseHeaders(int,long)
to send the response headers. Must be called before next step.getResponseBody()
to get aOutputStream
to send the response body. When the response body has been written, the stream must be closed to terminate the exchange.
Exchanges are terminated when both the request
InputStream
and
response OutputStream
are closed. Closing the OutputStream
,
implicitly closes the InputStream
(if it is not already closed).
However, it is recommended to consume all the data from the InputStream
before closing it. The convenience method close()
does all of these
tasks. Closing an exchange without consuming all of the request body is not
an error but may make the underlying TCP connection unusable for following
exchanges. The effect of failing to terminate an exchange is undefined, but
will typically result in resources failing to be freed/reused.- Since:
- 1.6
-
Constructor Summary
-
Method Summary
Modifier and TypeMethodDescriptionabstract void
close()
Ends this exchange by doing the following in sequence: close the requestInputStream
, if not already closed.abstract Object
getAttribute
(String name) Filter
modules may store arbitrary objects withHttpExchange
instances as an out-of-band communication mechanism.abstract HttpContext
Returns theHttpContext
for this exchange.abstract InetSocketAddress
Returns the local address on which the request was received.abstract HttpPrincipal
If an authenticator is set on theHttpContext
that owns this exchange, then this method will return theHttpPrincipal
that represents the authenticated user for thisHttpExchange
.abstract String
Returns the protocol string from the request in the form protocol/majorVersion.minorVersion.abstract InetSocketAddress
Returns the address of the remote entity invoking this request.abstract InputStream
Returns a stream from which the request body can be read.abstract Headers
Returns an immutableHeaders
containing the HTTP headers that were included with this request.abstract String
Returns the request method.abstract URI
Returns the requestURI
.abstract OutputStream
Returns a stream to which the response body must be written.abstract int
Returns the response code, if it has already been set.abstract Headers
Returns a mutableHeaders
into which the HTTP response headers can be stored and which will be transmitted as part of this response.abstract void
sendResponseHeaders
(int rCode, long responseLength) Starts sending the response back to the client using the current set of response headers and the numeric response code as specified in this method.abstract void
setAttribute
(String name, Object value) Filter
modules may store arbitrary objects withHttpExchange
instances as an out-of-band communication mechanism.abstract void
Used by Filters to wrap either (or both) of this exchange'sInputStream
andOutputStream
, with the given filtered streams so that subsequent calls togetRequestBody()
will return the givenInputStream
, and calls togetResponseBody()
will return the givenOutputStream
.
-
Constructor Details
-
HttpExchange
protected HttpExchange()Constructor for subclasses to call.
-
-
Method Details
-
getRequestHeaders
Returns an immutableHeaders
containing the HTTP headers that were included with this request.The keys in this
Headers
are the header names, while the values are aList
of Strings containing each value that was included in the request, in the order they were included. Header fields appearing multiple times are represented as multiple string values.The keys in
Headers
are case-insensitive.- Specified by:
getRequestHeaders
in interfaceRequest
- Returns:
- a read-only
Headers
which can be used to access request headers.
-
getResponseHeaders
Returns a mutableHeaders
into which the HTTP response headers can be stored and which will be transmitted as part of this response.The keys in the
Headers
are the header names, while the values must be aList
of Strings containing each value that should be included multiple times (in the order that they should be included).The keys in
Headers
are case-insensitive.- Returns:
- a writable
Headers
which can be used to set response headers.
-
getRequestURI
Returns the requestURI
.- Specified by:
getRequestURI
in interfaceRequest
- Returns:
- the request
URI
-
getRequestMethod
Returns the request method.- Specified by:
getRequestMethod
in interfaceRequest
- Returns:
- the request method string
-
getHttpContext
Returns theHttpContext
for this exchange.- Returns:
- the
HttpContext
-
close
public abstract void close()Ends this exchange by doing the following in sequence:- close the request
InputStream
, if not already closed. - close the response
OutputStream
, if not already closed.
- Specified by:
close
in interfaceAutoCloseable
- close the request
-
getRequestBody
Returns a stream from which the request body can be read. Multiple calls to this method will return the same stream. It is recommended that applications should consume (read) all of the data from this stream before closing it. If a stream is closed before all data has been read, then theInputStream.close()
call will read and discard remaining data (up to an implementation specific number of bytes).- Returns:
- the stream from which the request body can be read
-
getResponseBody
Returns a stream to which the response body must be written.sendResponseHeaders(int,long)
) must be called prior to calling this method. Multiple calls to this method (for the same exchange) will return the same stream. In order to correctly terminate each exchange, the output stream must be closed, even if no response body is being sent.Closing this stream implicitly closes the
InputStream
returned fromgetRequestBody()
(if it is not already closed).If the call to
sendResponseHeaders(int, long)
specified a fixed response body length, then the exact number of bytes specified in that call must be written to this stream. If too many bytes are written, then the write method ofOutputStream
will throw anIOException
. If too few bytes are written then the streamOutputStream.close()
will throw anIOException
. In both cases, the exchange is aborted and the underlying TCP connection closed.- Returns:
- the stream to which the response body is written
-
sendResponseHeaders
Starts sending the response back to the client using the current set of response headers and the numeric response code as specified in this method. The response body length is also specified as follows. If the response length parameter is greater thanzero
, this specifies an exact number of bytes to send and the application must send that exact amount of data. If the response length parameter iszero
, then chunked transfer encoding is used and an arbitrary amount of data may be sent. The application terminates the response body by closing theOutputStream
. If response length has the value-1
then no response body is being sent.If the content-length response header has not already been set then this is set to the appropriate value depending on the response length parameter.
This method must be called prior to calling
getResponseBody()
.- Implementation Note:
- This implementation allows the caller to instruct the
server to force a connection close after the exchange terminates, by
supplying a
Connection: close
header to the response headers beforesendResponseHeaders
is called. - Parameters:
rCode
- the response code to sendresponseLength
- if > 0, specifies a fixed response body length and that exact number of bytes must be written to the stream acquired fromgetResponseCode()
If == 0, then chunked encoding is used, and an arbitrary number of bytes may be written. If <= -1, then no response body length is specified and no response body may be written.- Throws:
IOException
- if the response headers have already been sent or an I/O error occurs- See Also:
-
getRemoteAddress
Returns the address of the remote entity invoking this request.- Returns:
- the
InetSocketAddress
of the caller
-
getResponseCode
public abstract int getResponseCode()Returns the response code, if it has already been set.- Returns:
- the response code, if available.
-1
if not available yet.
-
getLocalAddress
Returns the local address on which the request was received.- Returns:
- the
InetSocketAddress
of the local interface
-
getProtocol
Returns the protocol string from the request in the form protocol/majorVersion.minorVersion. For example, "HTTP/1.1
".- Returns:
- the protocol string from the request
-
getAttribute
Filter
modules may store arbitrary objects withHttpExchange
instances as an out-of-band communication mechanism. Other filters or the exchange handler may then access these objects.Each
Filter
class will document the attributes which they make available.- Parameters:
name
- the name of the attribute to retrieve- Returns:
- the attribute object, or
null
if it does not exist - Throws:
NullPointerException
- if name isnull
-
setAttribute
Filter
modules may store arbitrary objects withHttpExchange
instances as an out-of-band communication mechanism. Other filters or the exchange handler may then access these objects.Each
Filter
class will document the attributes which they make available.- Parameters:
name
- the name to associate with the attribute valuevalue
- the object to store as the attribute value.null
value is permitted.- Throws:
NullPointerException
- if name isnull
-
setStreams
Used by Filters to wrap either (or both) of this exchange'sInputStream
andOutputStream
, with the given filtered streams so that subsequent calls togetRequestBody()
will return the givenInputStream
, and calls togetResponseBody()
will return the givenOutputStream
. The streams provided to this call must wrap the original streams, and may be (but are not required to be) sub-classes ofFilterInputStream
andFilterOutputStream
.- Parameters:
i
- the filtered input stream to set as this object'sInputstream
, ornull
if no changeo
- the filtered output stream to set as this object'sOutputstream
, ornull
if no change
-
getPrincipal
If an authenticator is set on theHttpContext
that owns this exchange, then this method will return theHttpPrincipal
that represents the authenticated user for thisHttpExchange
.- Returns:
- the
HttpPrincipal
, ornull
if no authenticator is set
-