CacheableCommandImpl (IBM WebSphere Application Server [dynacache])

com.ibm.websphere.command
Class CacheableCommandImpl
java.lang.Object
  |
  +--com.ibm.websphere.command.TargetableCommandImpl
        |
        +--com.ibm.websphere.command.CacheableCommandImpl
All Implemented Interfaces:
CacheableCommand, com.ibm.websphere.command.Command, CommandCaller, java.io.Serializable, com.ibm.websphere.command.TargetableCommand

public abstract class CacheableCommandImpl
extends com.ibm.websphere.command.TargetableCommandImpl
implements CacheableCommand

This CacheableCommandImpl abstract class provides an implementation for all CacheableCommand interface methods except those that the command writer must write. This class provides a runtime for command execution that interacts with the CommandCache. It also provides the contract between this command runtime and the command writer.
CacheableCommandImpl is a super class of all CacheableCommands.

See Also:
Serialized Form

Field Summary

Fields inherited from class com.ibm.websphere.command.TargetableCommandImpl

commandTarget, commandTargetName, hasOutputProperties, LOCAL, targetPolicy

Fields inherited from interface com.ibm.websphere.command.Command

serialVersionUID

Constructor Summary

CacheableCommandImpl()


Method Summary

void execute()
          This implements the method in the Command interface, overriding the implementation in TargetableCommandImpl.

boolean executeFromCache()
          executeFromCache This method will check the cache to see if the given command is present.

CommandCaller getCaller()
          Implements the CacheableCommand interface method.

EntryInfo getEntryInfo()
          The gets this command's EntryInfo object, which holds its caching metadata.

java.lang.String getId()
          This is the method in the CacheableCommand interface.

int getSharingPolicy()
          This is the method in the CacheableCommand interface.

void postExecute()
          Implements the CacheableCommand interface.

boolean preExecute()
          This implements the CacheableCommand interface.

protected void prepareMetadata()
          This method implements the default command cache policy

void reset()
          Reset the command for reuse...

void setCaller(CommandCaller caller)
          Implements the CacheableCommand interface method.

void unionDependencies(EntryInfo entryInfo)
          This is called by the CommandCache to add dependencies to this command.

void updateCache()
          This method will cause the current command to be placed into the cache.

Methods inherited from class com.ibm.websphere.command.TargetableCommandImpl

getCommandTarget, getCommandTargetName, getTargetPolicy, hasOutputProperties, isReadyToCallExecute, performExecute, setCommandTarget, setCommandTargetName, setHasOutputProperties, setOutputProperties, setTargetPolicy

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.ibm.websphere.command.TargetableCommand

getCommandTarget, getCommandTargetName, hasOutputProperties, performExecute, setCommandTarget, setCommandTargetName, setOutputProperties

Methods inherited from interface com.ibm.websphere.command.Command

isReadyToCallExecute

Constructor Detail

CacheableCommandImpl
public CacheableCommandImpl()
Method Detail

getId
public final java.lang.String getId()
This is the method in the CacheableCommand interface. This must be implemented by the command writer.

Specified by:
getId in interface CacheableCommand

Returns:
The cache id.

getSharingPolicy
public final int getSharingPolicy()
This is the method in the CacheableCommand interface. This should be implemented by the command writer only if the default of EntryInfo.SHARED_PULL is not desired.

Specified by:
getSharingPolicy in interface CacheableCommand

Returns:
The sharing policy id.

preExecute
public boolean preExecute()
This implements the CacheableCommand interface. This should be implemented by the command writer only if there is something that needs to be done prior to executing the command on the server.

Specified by:
preExecute in interface CacheableCommand

Returns:
True implies that the command's execution should be terminated, so the performExecute, postExecute and setCommand will not happen.

postExecute
public void postExecute()
Implements the CacheableCommand interface. This should be implemented by the command writer only if there is something that needs to be done after executing the command on the server.

Specified by:
postExecute in interface CacheableCommand

execute
public void execute()
             throws com.ibm.websphere.command.CommandException
This implements the method in the Command interface, overriding the implementation in TargetableCommandImpl.
It does the following:

Throws an UnsetInputPropertiesException if this command's isReadyToCallExecute method returns false.
Get the CommandTarget for this command from the targetPolicy.
If it is cached, return the cached command. The command may be cached locally or in the coordinator for the command.
If it is not cached, call the CommandTargetProxy.executeCommand method to execute the command, which calls the TargetableCommand.performExecute method, and cache it. The command may be run locally or in the coordinator for the command. The command may be cached after execution, depending on the sharing policy.
If the hasOutputProperties method returns true and the returned command is not the same instance as this command, it calls the setOutputProperties method so that the results will be copied into this command.
Set the time of execution of the command.

Specified by:
execute in interface com.ibm.websphere.command.Command
Overrides:
execute in class com.ibm.websphere.command.TargetableCommandImpl

Throws:
CommandException - The superclass for all command exceptions.

setCaller
public void setCaller(CommandCaller caller)
Implements the CacheableCommand interface method.

Specified by:
setCaller in interface CacheableCommand

Parameters:
caller - The command that called this command.

getCaller
public CommandCaller getCaller()
Implements the CacheableCommand interface method.

Specified by:
getCaller in interface CacheableCommand

Returns:
The caller of the command.

unionDependencies
public void unionDependencies(EntryInfo entryInfo)
This is called by the CommandCache to add dependencies to this command.

Specified by:
unionDependencies in interface CommandCaller

Parameters:
entryInfo - This command's entryInfo.

getEntryInfo
public EntryInfo getEntryInfo()
The gets this command's EntryInfo object, which holds its caching metadata.

Specified by:
getEntryInfo in interface CacheableCommand

Returns:
The EntryInfo object.

reset
public void reset()
Reset the command for reuse...

Specified by:
reset in interface com.ibm.websphere.command.Command
Specified by:
reset in class com.ibm.websphere.command.TargetableCommandImpl

executeFromCache
public boolean executeFromCache()
                         throws com.ibm.websphere.command.CommandException
executeFromCache This method will check the cache to see if the given command is present. If so then the command is populated with the cached results and true is returned. If the command is not cached, then false is returned and no change is made to the state of the command.

Specified by:
executeFromCache in interface CacheableCommand

Returns:
true if the command was retrieved from cache
com.ibm.websphere.command.CommandException

updateCache
public void updateCache()
This method will cause the current command to be placed into the cache. Any existing entry with the same cache id will be replaced.

Specified by:
updateCache in interface CacheableCommand

prepareMetadata
protected void prepareMetadata()
This method implements the default command cache policy

WebSphere is a trademark of the IBM Corporation in the United States, other countries, or both.

IBM is a trademark of the IBM Corporation in the United States, other countries, or both.

Method Summary
void	execute() This implements the method in the Command interface, overriding the implementation in TargetableCommandImpl.
boolean	executeFromCache() executeFromCache This method will check the cache to see if the given command is present.
CommandCaller	getCaller() Implements the CacheableCommand interface method.
EntryInfo	getEntryInfo() The gets this command's EntryInfo object, which holds its caching metadata.
java.lang.String	getId() This is the method in the CacheableCommand interface.
int	getSharingPolicy() This is the method in the CacheableCommand interface.
void	postExecute() Implements the CacheableCommand interface.
boolean	preExecute() This implements the CacheableCommand interface.
protected void	prepareMetadata() This method implements the default command cache policy
void	reset() Reset the command for reuse...
void	setCaller(CommandCaller caller) Implements the CacheableCommand interface method.
void	unionDependencies(EntryInfo entryInfo) This is called by the CommandCache to add dependencies to this command.
void	updateCache() This method will cause the current command to be placed into the cache.

com.ibm.websphere.command Class CacheableCommandImpl

CacheableCommandImpl

getId

getSharingPolicy

preExecute

postExecute

execute

setCaller

getCaller

unionDependencies

getEntryInfo

reset

executeFromCache

updateCache

prepareMetadata

com.ibm.websphere.command
Class CacheableCommandImpl