Java Reference
In-Depth Information
for
for
(
AsyncResponse async
:
listeners
)
{
try
try
{
send
(
base
,
async
,
message
);
}
catch
catch
(
Exception e
)
{
e
.
printStackTrace
();
}
}
listeners
.
clear
();
}
}
});
}
Finally, the
writer
thread loops through all waiting chat clients and sends them the new mes-
sage.
Handling poll requests
The
CustomerChat.receive()
method handles GET requests from chat clients:
@GET
public
public
void
void
receive
(
@QueryParam
(
"current"
)
String id
,
@Suspended
AsyncResponse async
)
{
final
final
UriBuilder base
=
uriInfo
.
getBaseUriBuilder
();
Message message
=
null
null
;
synchronized
synchronized
(
messages
)
{
Message current
=
messages
.
get
(
id
);
iif
(
current
==
null
null
)
message
=
first
;
else
else
message
=
current
.
next
;
iif
(
message
==
null
null
) {
queue
(
async
);
}
}
// do this outside of synchronized block to reduce lock hold time
iif
(
message
!=
null
null
)
send
(
base
,
async
,
message
);
}
The
receive()
method takes a query parameter,
current
. This parameter is the
id
of the
last message the chat client read. This parameter is allowed to be
null
if this is the chat cli-
