Package org.apache.catalina.tribes
Interface ChannelInterceptor
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- All Superinterfaces:
Heartbeat
,MembershipListener
- All Known Implementing Classes:
ChannelCoordinator
,ChannelInterceptorBase
,DomainFilterInterceptor
,EncryptInterceptor
,FragmentationInterceptor
,GroupChannel
,GzipInterceptor
,MessageDispatchInterceptor
,NonBlockingCoordinator
,OrderInterceptor
,SimpleCoordinator
,StaticMembershipInterceptor
,TcpFailureDetector
,TcpPingInterceptor
,ThroughputInterceptor
,TwoPhaseCommitInterceptor
public interface ChannelInterceptor extends MembershipListener, Heartbeat
A ChannelInterceptor is an interceptor that intercepts messages and membership messages in the channel stack. This allows interceptors to modify the message or perform other actions when a message is sent or received.
Interceptors are tied together in a linked list.- See Also:
ChannelInterceptorBase
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Nested Class Summary
Nested Classes Modifier and Type Interface Description static interface
ChannelInterceptor.InterceptorEvent
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description void
fireInterceptorEvent(ChannelInterceptor.InterceptorEvent event)
Channel
getChannel()
Return the channel that is related to this interceptorMember
getLocalMember(boolean incAliveTime)
Intercepts theChannel.getLocalMember(boolean)
methodMember
getMember(Member mbr)
Intercepts theChannel.getMember(Member)
methodMember[]
getMembers()
Intercepts theChannel.getMembers()
methodChannelInterceptor
getNext()
Retrieve the next interceptor in the listint
getOptionFlag()
An interceptor can react to a message based on a set bit on the message options.ChannelInterceptor
getPrevious()
Retrieve the previous interceptor in the listboolean
hasMembers()
Intercepts theChannel.hasMembers()
methodvoid
heartbeat()
Theheartbeat()
method gets invoked periodically to allow interceptors to clean up resources, time out object and perform actions that are unrelated to sending/receiving data.void
messageReceived(ChannelMessage data)
themessageReceived
is invoked when a message is received.void
sendMessage(Member[] destination, ChannelMessage msg, InterceptorPayload payload)
ThesendMessage
method is called when a message is being sent to one more destinations.void
setChannel(Channel channel)
Set the channel that is related to this interceptorvoid
setNext(ChannelInterceptor next)
Set the next interceptor in the list of interceptorsvoid
setOptionFlag(int flag)
Sets the option flagvoid
setPrevious(ChannelInterceptor previous)
Set the previous interceptor in the listvoid
start(int svc)
Starts up the channel.void
stop(int svc)
Shuts down the channel.-
Methods inherited from interface org.apache.catalina.tribes.MembershipListener
memberAdded, memberDisappeared
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Method Detail
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getOptionFlag
int getOptionFlag()
An interceptor can react to a message based on a set bit on the message options.
When a message is sent, the options can be retrieved from ChannelMessage.getOptions() and if the bit is set, this interceptor will react to it.
A simple evaluation if an interceptor should react to the message would be:
boolean react = (getOptionFlag() == (getOptionFlag() & ChannelMessage.getOptions()));
The default option is 0, meaning there is no way for the application to trigger the interceptor. The interceptor itself will decide.- Returns:
- int
- See Also:
ChannelMessage.getOptions()
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setOptionFlag
void setOptionFlag(int flag)
Sets the option flag- Parameters:
flag
- int- See Also:
getOptionFlag()
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setNext
void setNext(ChannelInterceptor next)
Set the next interceptor in the list of interceptors- Parameters:
next
- ChannelInterceptor
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getNext
ChannelInterceptor getNext()
Retrieve the next interceptor in the list- Returns:
- ChannelInterceptor - returns the next interceptor in the list or null if no more interceptors exist
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setPrevious
void setPrevious(ChannelInterceptor previous)
Set the previous interceptor in the list- Parameters:
previous
- ChannelInterceptor
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getPrevious
ChannelInterceptor getPrevious()
Retrieve the previous interceptor in the list- Returns:
- ChannelInterceptor - returns the previous interceptor in the list or null if no more interceptors exist
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sendMessage
void sendMessage(Member[] destination, ChannelMessage msg, InterceptorPayload payload) throws ChannelException
ThesendMessage
method is called when a message is being sent to one more destinations. The interceptor can modify any of the parameters and then pass on the message down the stack by invokinggetNext().sendMessage(destination,msg,payload)
Alternatively the interceptor can stop the message from being sent by not invokinggetNext().sendMessage(destination,msg,payload)
If the message is to be sent asynchronous the application can be notified of completion and errors by passing in an error handler attached to a payload object.
The ChannelMessage.getAddress contains Channel.getLocalMember, and can be overwritten to simulate a message sent from another node.- Parameters:
destination
- Member[] - the destination for this messagemsg
- ChannelMessage - the message to be sentpayload
- InterceptorPayload - the payload, carrying an error handler and future useful data, can be null- Throws:
ChannelException
- if a serialization error happens.- See Also:
ErrorHandler
,InterceptorPayload
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messageReceived
void messageReceived(ChannelMessage data)
themessageReceived
is invoked when a message is received.ChannelMessage.getAddress()
is the sender, or the reply-to address if it has been overwritten.- Parameters:
data
- ChannelMessage
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heartbeat
void heartbeat()
Theheartbeat()
method gets invoked periodically to allow interceptors to clean up resources, time out object and perform actions that are unrelated to sending/receiving data.
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hasMembers
boolean hasMembers()
Intercepts theChannel.hasMembers()
method- Returns:
- boolean - if the channel has members in its membership group
- See Also:
Channel.hasMembers()
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getMembers
Member[] getMembers()
Intercepts theChannel.getMembers()
method- Returns:
- Member[]
- See Also:
Channel.getMembers()
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getLocalMember
Member getLocalMember(boolean incAliveTime)
Intercepts theChannel.getLocalMember(boolean)
method- Parameters:
incAliveTime
- boolean- Returns:
- Member
- See Also:
Channel.getLocalMember(boolean)
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getMember
Member getMember(Member mbr)
Intercepts theChannel.getMember(Member)
method- Parameters:
mbr
- Member- Returns:
- Member - the actual member information, including stay alive
- See Also:
Channel.getMember(Member)
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start
void start(int svc) throws ChannelException
Starts up the channel. This can be called multiple times for individual services to start The svc parameter can be the logical or value of any constants- Parameters:
svc
- int value of
Channel.DEFAULT - will start all services
Channel.MBR_RX_SEQ - starts the membership receiver
Channel.MBR_TX_SEQ - starts the membership broadcaster
Channel.SND_TX_SEQ - starts the replication transmitter
Channel.SND_RX_SEQ - starts the replication receiver- Throws:
ChannelException
- if a startup error occurs or the service is already started.- See Also:
Channel
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stop
void stop(int svc) throws ChannelException
Shuts down the channel. This can be called multiple times for individual services to shutdown The svc parameter can be the logical or value of any constants- Parameters:
svc
- int value of
Channel.DEFAULT - will shutdown all services
Channel.MBR_RX_SEQ - stops the membership receiver
Channel.MBR_TX_SEQ - stops the membership broadcaster
Channel.SND_TX_SEQ - stops the replication transmitter
Channel.SND_RX_SEQ - stops the replication receiver- Throws:
ChannelException
- if a startup error occurs or the service is already started.- See Also:
Channel
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fireInterceptorEvent
void fireInterceptorEvent(ChannelInterceptor.InterceptorEvent event)
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getChannel
Channel getChannel()
Return the channel that is related to this interceptor- Returns:
- Channel
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setChannel
void setChannel(Channel channel)
Set the channel that is related to this interceptor- Parameters:
channel
- The channel
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