- java.lang.Object
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- com.sun.net.httpserver.HttpExchange
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- Direct Known Subclasses:
HttpsExchange
public abstract class HttpExchange extends Object
This class encapsulates a HTTP request received and a response to be generated in one exchange. It provides methods for examining the request from the client, and for building and sending the response.The typical life-cycle of a HttpExchange is shown in the sequence below.
getRequestMethod()
to determine the commandgetRequestHeaders()
to examine the request headers (if needed)getRequestBody()
returns aInputStream
for reading the request body. After reading the request body, the stream is close.getResponseHeaders()
to set any response headers, except content-lengthsendResponseHeaders(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 methodclose()
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
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Constructor Summary
Constructors Modifier Constructor Description protected
HttpExchange()
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description 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.abstract Object
getAttribute(String name)
Filter modules may store arbitrary objects with HttpExchange instances as an out-of-band communication mechanism.abstract HttpContext
getHttpContext()
Get the HttpContext for this exchangeabstract InetSocketAddress
getLocalAddress()
Returns the local address on which the request was receivedabstract HttpPrincipal
getPrincipal()
If an authenticator is set on the HttpContext that owns this exchange, then this method will return theHttpPrincipal
that represents the authenticated user for this HttpExchange.abstract String
getProtocol()
Returns the protocol string from the request in the form protocol/majorVersion.minorVersion.abstract InetSocketAddress
getRemoteAddress()
Returns the address of the remote entity invoking this requestabstract InputStream
getRequestBody()
returns a stream from which the request body can be read.abstract Headers
getRequestHeaders()
Returns an immutable Map containing the HTTP headers that were included with this request.abstract String
getRequestMethod()
Get the request methodabstract URI
getRequestURI()
Get the request URIabstract OutputStream
getResponseBody()
returns a stream to which the response body must be written.abstract int
getResponseCode()
Returns the response code, if it has already been setabstract Headers
getResponseHeaders()
Returns a mutable Map 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 with HttpExchange instances as an out-of-band communication mechanism.abstract void
setStreams(InputStream i, OutputStream o)
Used by Filters to wrap either (or both) of this exchange's InputStream and OutputStream, with the given filtered streams so that subsequent calls togetRequestBody()
will return the givenInputStream
, and calls togetResponseBody()
will return the givenOutputStream
.
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Method Detail
getRequestHeaders
public abstract Headers getRequestHeaders()
Returns an immutable Map containing the HTTP headers that were included with this request. The keys in this Map will be the header names, while the values will be a List of Strings containing each value that was included (either for a header that was listed several times, or one that accepts a comma-delimited list of values on a single line). In either of these cases, the values for the header name will be presented in the order that they were included in the request.The keys in Map are case-insensitive.
- Returns:
- a read-only Map which can be used to access request headers
getResponseHeaders
public abstract Headers getResponseHeaders()
Returns a mutable Map into which the HTTP response headers can be stored and which will be transmitted as part of this response. The keys in the Map will be the header names, while the values must be a List of Strings containing each value that should be included multiple times (in the order that they should be included).The keys in Map are case-insensitive.
- Returns:
- a writable Map which can be used to set response headers.
getRequestURI
public abstract URI getRequestURI()
Get the request URI- Returns:
- the request URI
getRequestMethod
public abstract String getRequestMethod()
Get the request method- Returns:
- the request method
getHttpContext
public abstract HttpContext getHttpContext()
Get the HttpContext 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.
getRequestBody
public abstract InputStream 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 the 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
public abstract OutputStream 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 from
getRequestBody()
(if it is not already closed).If the call to sendResponseHeaders() 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 write() will throw an IOException. If too few bytes are written then the stream close() will throw an IOException. In both cases, the exchange is aborted and the underlying TCP connection closed.
- Returns:
- the stream to which the response body is written
sendResponseHeaders
public abstract void sendResponseHeaders(int rCode, long responseLength) throws IOException
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 than zero, 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 the OutputStream. 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()
.- 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 from getResponseBody(), or else if equal to 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
- See Also:
getResponseBody()
getRemoteAddress
public abstract InetSocketAddress 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
public abstract InetSocketAddress getLocalAddress()
Returns the local address on which the request was received- Returns:
- the InetSocketAddress of the local interface
getProtocol
public abstract String 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
public abstract Object getAttribute(String name)
Filter modules may store arbitrary objects with HttpExchange 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
public abstract void setAttribute(String name, Object value)
Filter modules may store arbitrary objects with HttpExchange 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
public abstract void setStreams(InputStream i, OutputStream o)
Used by Filters to wrap either (or both) of this exchange's InputStream and OutputStream, 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's inputstream, ornull
if no change.o
- the filtered output stream to set as this object's outputstream, ornull
if no change.
getPrincipal
public abstract HttpPrincipal getPrincipal()
If an authenticator is set on the HttpContext that owns this exchange, then this method will return theHttpPrincipal
that represents the authenticated user for this HttpExchange.- Returns:
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the HttpPrincipal, or
null
if no authenticator is set.
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