PessimisticMapWrapper (Commons Transaction 1.3-SNAPSHOT API)

java.lang.Object
- org.apache.commons.transaction.memory.TransactionalMapWrapper
- - org.apache.commons.transaction.memory.PessimisticMapWrapper

All Implemented Interfaces:

Map, Status
```
public class PessimisticMapWrapper
extends TransactionalMapWrapper
```
Wrapper that adds transactional control to all kinds of maps that implement the Map interface. By using pessimistic transaction control (blocking locks) this wrapper has better isolation than TransactionalMapWrapper, but also has less possible concurrency and may even deadlock. A commit, however, will never fail.
Start a transaction by calling startTransaction(). Then perform the normal actions on the map and finally either call TransactionalMapWrapper.commitTransaction() to make your changes permanent or TransactionalMapWrapper.rollbackTransaction() to undo them.
Caution: Do not modify values retrieved by TransactionalMapWrapper.get(Object) as this will circumvent the transactional mechanism. Rather clone the value or copy it in a way you see fit and store it back using put(Object, Object).
Note: This wrapper guarantees isolation level SERIALIZABLE.

Version:

$Id: PessimisticMapWrapper.java 493628 2007-01-07 01:42:48Z joerg $

See Also:
TransactionalMapWrapper, OptimisticMapWrapper

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

class PessimisticMapWrapper.LockingTxContext
- Nested classes/interfaces inherited from class org.apache.commons.transaction.memory.TransactionalMapWrapper
  TransactionalMapWrapper.HashEntry, TransactionalMapWrapper.TxContext
- Nested classes/interfaces inherited from interface java.util.Map
  Map.Entry

Nested Classes
Modifier and Type	Class and Description
`class`	`PessimisticMapWrapper.LockingTxContext`

Field Summary

Fields
Modifier and Type	Field and Description
`protected static Object`	`GLOBAL_LOCK`
`protected ReadWriteLockManager`	`lockManager`
`protected static int`	`READ`
`protected long`	`readTimeOut`
`protected static int`	`WRITE`

Fields inherited from class org.apache.commons.transaction.memory.TransactionalMapWrapper
mapFactory, setFactory, wrapped

Fields inherited from interface javax.transaction.Status
STATUS_ACTIVE, STATUS_COMMITTED, STATUS_COMMITTING, STATUS_MARKED_ROLLBACK, STATUS_NO_TRANSACTION, STATUS_PREPARED, STATUS_PREPARING, STATUS_ROLLEDBACK, STATUS_ROLLING_BACK, STATUS_UNKNOWN

Constructor Summary

Constructors
Constructor and Description
`PessimisticMapWrapper(Map wrapped, LoggerFacade logger)` Creates a new pessimistic transactional map wrapper.
`PessimisticMapWrapper(Map wrapped, MapFactory mapFactory, SetFactory setFactory, LoggerFacade logger)` Creates a new pessimistic transactional map wrapper.

Method Summary

Methods
Modifier and Type	Method and Description
`protected void`	`assureGlobalReadLock()`
`protected void`	`assureWriteLock(Object key)`
`Set`	`entrySet()`
`Set`	`keySet()`
`Object`	`put(Object key, Object value)`
`Object`	`remove(Object key)`
`void`	`startTransaction()` Starts a new transaction and associates it with the current thread.
`Collection`	`values()`

Methods inherited from class org.apache.commons.transaction.memory.TransactionalMapWrapper
clear, commitTransaction, containsKey, containsValue, get, getActiveTx, getTransactionState, isEmpty, isReadOnly, isTransactionMarkedForRollback, markTransactionForRollback, putAll, resumeTransaction, rollbackTransaction, setActiveTx, size, suspendTransaction

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Map
equals, hashCode

- Field Detail
  - READ
```
protected static final int READ
```
    See Also:
    Constant Field Values
  - WRITE
```
protected static final int WRITE
```
    See Also:
    Constant Field Values
  - GLOBAL_LOCK
```
protected static final Object GLOBAL_LOCK
```
  - lockManager
```
protected ReadWriteLockManager lockManager
```
  - readTimeOut
```
protected long readTimeOut
```
- Constructor Detail
  - PessimisticMapWrapper
```
public PessimisticMapWrapper(Map wrapped,
                     LoggerFacade logger)
```
    Creates a new pessimistic transactional map wrapper. Temporary maps and sets to store transactional data will be instances of HashMap and HashSet.
    
    Parameters:
    wrapped - map to be wrapped
    logger - generic logger used for all kinds of logging
  - PessimisticMapWrapper
```
public PessimisticMapWrapper(Map wrapped,
                     MapFactory mapFactory,
                     SetFactory setFactory,
                     LoggerFacade logger)
```
    Creates a new pessimistic transactional map wrapper. Temporary maps and sets to store transactional data will be created and disposed using MapFactory and SetFactory.
    
    Parameters:
    wrapped - map to be wrapped
    mapFactory - factory for temporary maps
    setFactory - factory for temporary sets
    logger - generic logger used for all kinds of logging
- Method Detail
  - startTransaction
```
public void startTransaction()
```
    Description copied from class: TransactionalMapWrapper
    
    Starts a new transaction and associates it with the current thread. All subsequent changes in the same thread made to the map are invisible from other threads until TransactionalMapWrapper.commitTransaction() is called. Use TransactionalMapWrapper.rollbackTransaction() to discard your changes. After calling either method there will be no transaction associated to the current thread any longer.
    
    Caution: Be careful to finally call one of those methods, as otherwise the transaction will lurk around for ever.
    
    Overrides:
    
    startTransaction in class TransactionalMapWrapper
    
    See Also:
    TransactionalMapWrapper.commitTransaction(), TransactionalMapWrapper.rollbackTransaction()
  - values
```
public Collection values()
```
    Specified by:
    
    values in interface Map
    
    Overrides:
    
    values in class TransactionalMapWrapper
    
    See Also:
    Map.values()
  - entrySet
```
public Set entrySet()
```
    Specified by:
    
    entrySet in interface Map
    
    Overrides:
    
    entrySet in class TransactionalMapWrapper
    
    See Also:
    Map.entrySet()
  - keySet
```
public Set keySet()
```
    Specified by:
    
    keySet in interface Map
    
    Overrides:
    
    keySet in class TransactionalMapWrapper
    
    See Also:
    Map.keySet()
  - remove
```
public Object remove(Object key)
```
    Specified by:
    
    remove in interface Map
    
    Overrides:
    
    remove in class TransactionalMapWrapper
    
    See Also:
    Map.remove(java.lang.Object)
  - put
```
public Object put(Object key,
         Object value)
```
    Specified by:
    
    put in interface Map
    
    Overrides:
    
    put in class TransactionalMapWrapper
    
    See Also:
    Map.put(java.lang.Object, java.lang.Object)
  - assureWriteLock
```
protected void assureWriteLock(Object key)
```
  - assureGlobalReadLock
```
protected void assureGlobalReadLock()
```

Class PessimisticMapWrapper

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.commons.transaction.memory.TransactionalMapWrapper

Nested classes/interfaces inherited from interface java.util.Map

Field Summary

Fields inherited from class org.apache.commons.transaction.memory.TransactionalMapWrapper

Fields inherited from interface javax.transaction.Status

Constructor Summary

Method Summary

Methods inherited from class org.apache.commons.transaction.memory.TransactionalMapWrapper

Methods inherited from class java.lang.Object

Methods inherited from interface java.util.Map

Field Detail

READ

WRITE

GLOBAL_LOCK

lockManager

readTimeOut

Constructor Detail

PessimisticMapWrapper

PessimisticMapWrapper

Method Detail

startTransaction

values

entrySet

keySet

remove

put

assureWriteLock

assureGlobalReadLock