br.shob
Interface SharedReference

All Known Implementing Classes:

DefaultSharedReference

public interface SharedReference

This class represents a reference to shared object. References are retrieved from a global space through the Shared Space instance.

  SharedReference ref = shob.get("myObject_global_name");
  if (ref instanceof List) {
      List l = (List) ref;
      readList(l);
  }

SharedReferences should not be shared among different threads for correctness. Synchronization and mutual exclusion should be left to the shared space. In fact, if you use shared references in multi-thread contexts, you should consider using ThreadLocal variables, each one initialized with it's own reference.

When creating shared references to your own-developed classes, you should use the configurator tool included in the SharedObjects package.

Version:

$Revision: 1.8 $

Author:

crolmos, dukejeffrie

Created:

August 30, 2002

Field Summary

static long

defaultLeaseTime This is the default lease time, set to 20 (twenty) seconds.

Method Summary

void	srBeginTrans() Initiates a transaction for this object.
Object	srCallMethod(String name, Class[] argTypes, Object[] args) This method calls a method from the shared object.
void	srCommit() Commits a transaction.
String	srGetGlobalName() Acessor for the global name.
boolean	srIsUpdated() Checks if the corresponding object is updated (i.e., if his lease is expired)
void	srRollback() Rolls back a transaction.
void	srUnshare() Unshares this object from the global space.
void	srValidate() Validates this object.

Field Detail

defaultLeaseTime

public static final long defaultLeaseTime

This is the default lease time, set to 20 (twenty) seconds.

See Also:

Constant Field Values

Method Detail

srBeginTrans

public void srBeginTrans()
                  throws ShobException,
                         AlreadyLockedException

Initiates a transaction for this object.

Throws:

ShobException - If a low-level error occurs

AlreadyLockedException - If the object is already locked by this reference.

srCallMethod

public Object srCallMethod(String name,
                           Class[] argTypes,
                           Object[] args)
                    throws InvocationException,
                           InvocationTargetException,
                           ShobException

This method calls a method from the shared object.
If the lease has expired it validates the object before the call is made.

Parameters:

name - the name of the method.

argTypes - the types of the arguments.

args - the arguments.

Returns:

the value returned by the method

Throws:

InvocationException - if the method does not exist, is not public or the argument is invalid (thrown with real cause chained)

InvocationTargetException - if the underlying method throws an exception.

ShobException - If a low-level error occurs

srCommit

public void srCommit()
              throws ShobException,
                     NotLockedException

Commits a transaction.

Throws:

ShobException - If a low-level error occurs

NotLockedException - if the object is not inside a transaction

srGetGlobalName

public String srGetGlobalName()

Acessor for the global name.

Returns:

the global name of the shared object.

srIsUpdated

public boolean srIsUpdated()

Checks if the corresponding object is updated (i.e., if his lease is expired)

Returns:

true if the local cache is up to date

srRollback

public void srRollback()
                throws ShobException,
                       NotLockedException

Rolls back a transaction.

Throws:

ShobException - If a low-level error occurs

NotLockedException - if the object is not inside a transaction

srUnshare

public void srUnshare()
               throws ShobException

Unshares this object from the global space.

Throws:

ShobException - If a low-level error occurs

srValidate

public void srValidate()
                throws ShobException

Validates this object.

Throws:

ShobException - If a low-level error occurs