-TransactionRunner (Oracle - Berkeley DB Java API) -

java.lang.Object
+
- com.sleepycat.collections.TransactionRunner
+

+
+

public class TransactionRunner
+extends java.lang.Object

Starts a transaction, calls TransactionWorker.doWork(), and handles transaction retry and exceptions. To perform a transaction, the user - implements the TransactionWorker interface and passes an instance of - that class to the run method. + implements the TransactionWorker interface and passes an instance of + that class to the run method.

A single TransactionRunner instance may be used by any number of threads for any number of transactions.

@@ -151,369 +149,338 @@ Starts a transaction, calls +

- - - - - - - - - - -

-Field Summary
-`static int`	`DEFAULT_MAX_RETRIES` - - - The default maximum number of retries.

- +

+ + +
Field Summary
+ + + + + + + + + + +
Fields
Modifier and Type Field and Description
static int DEFAULT_MAX_RETRIES +
The default maximum number of retries.
+
+

Fields
Modifier and Type	Field and Description
`static int`	`DEFAULT_MAX_RETRIES` + The default maximum number of retries. +

- - - - - - - - - - - - -

-Constructor Summary
`TransactionRunner(Environment env)` - - - Creates a transaction runner for a given Berkeley DB environment.
`TransactionRunner(Environment env, - int maxRetries, - TransactionConfig config)` - - - Creates a transaction runner for a given Berkeley DB environment and - with a given number of maximum retries.

- +

+ + +

Constructor Summary

+ + + + + + + + + + + +

Constructors
Constructor and Description
`TransactionRunner(Environment env)` + Creates a transaction runner for a given Berkeley DB environment. +
`TransactionRunner(Environment env, + int maxRetries, + TransactionConfig config)` + Creates a transaction runner for a given Berkeley DB environment and + with a given number of maximum retries. +

- - - - - - - - - + + + + + + + + + +

-Method Summary

- boolean

getAllowNestedTransactions() - -
- Returns whether nested transactions will be created if +

+ + +

Method Summary

+ + + + + + + + + - - - - - - - - - - - - - - - - - - - - + + + + + + + + + + + + + + + + + + + + - - - - - - - - - -

Methods
Modifier and Type	Method and Description
`boolean`	`getAllowNestedTransactions()` + Returns whether nested transactions will be created if `run()` is called when a transaction is already active for - the current thread.
- `int`	`getMaxRetries()` - - - Returns the maximum number of retries that will be performed when - deadlocks are detected.
- `TransactionConfig`	`getTransactionConfig()` - - - Returns the transaction configuration used for calling - `Environment.beginTransaction(com.sleepycat.db.Transaction, com.sleepycat.db.TransactionConfig)`.
- `int`	`handleException(Exception exception, - int retries, - int maxRetries)` - - - Handles exceptions that occur during a transaction, and may implement - transaction retry policy.
- `void`	`run(TransactionWorker worker)` - - - Calls the `TransactionWorker.doWork()` method and, for transactional - environments, may begin and end a transaction.
- `void`	`setAllowNestedTransactions(boolean allowNestedTxn)` - - - Changes whether nested transactions will be created if + the current thread. +
`int`	`getMaxRetries()` + Returns the maximum number of retries that will be performed when + deadlocks are detected. +
`TransactionConfig`	`getTransactionConfig()` + Returns the transaction configuration used for calling + `Environment.beginTransaction(com.sleepycat.db.Transaction, com.sleepycat.db.TransactionConfig)`. +
`int`	`handleException(java.lang.Exception exception, + int retries, + int maxRetries)` + Handles exceptions that occur during a transaction, and may implement + transaction retry policy. +
`void`	`run(TransactionWorker worker)` + Calls the `TransactionWorker.doWork()` method and, for transactional + environments, may begin and end a transaction. +
`void`	`setAllowNestedTransactions(boolean allowNestedTxn)` + Changes whether nested transactions will be created if `run()` is called when a transaction is already active for - the current thread.
- `void`	`setMaxRetries(int maxRetries)` - - - Changes the maximum number of retries that will be performed when - deadlocks are detected.
- `void`	`setTransactionConfig(TransactionConfig config)` - - - Changes the transaction configuration used for calling - `Environment.beginTransaction(com.sleepycat.db.Transaction, com.sleepycat.db.TransactionConfig)`.

- - - - - - - - -

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

- -

- + the current thread. +

void

setMaxRetries(int maxRetries) +

Changes the maximum number of retries that will be performed when + deadlocks are detected.

void

setTransactionConfig(TransactionConfig config) +

Changes the transaction configuration used for calling + Environment.beginTransaction(com.sleepycat.db.Transaction, com.sleepycat.db.TransactionConfig).

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

- - - - - - -
-Field Detail
- -
-DEFAULT_MAX_RETRIES
-
```
-public static final int DEFAULT_MAX_RETRIES
```
-
-
The default maximum number of retries. -
-
-
See Also:
Constant Field Values
-
- +
- + + +
  Field Detail
  + + + +
  - +
    DEFAULT_MAX_RETRIES
    +
```
public static final int DEFAULT_MAX_RETRIES
```
    +
    The default maximum number of retries.
    +
    See Also:
    Constant Field Values
    +
  +
- - - - - - -
-Constructor Detail
- -
-TransactionRunner
-
```
-public TransactionRunner(Environment env)
```
-
-
Creates a transaction runner for a given Berkeley DB environment. - The default maximum number of retries (DEFAULT_MAX_RETRIES) and - a null (default) TransactionConfig will be used. -
-
-
Parameters:
env - is the environment for running transactions.
-
-
- -
-TransactionRunner
-
```
-public TransactionRunner(Environment env,
-                         int maxRetries,
-                         TransactionConfig config)
```
-
-
Creates a transaction runner for a given Berkeley DB environment and - with a given number of maximum retries. -
-
-
Parameters:
env - is the environment for running transactions.
maxRetries - is the maximum number of retries that will be - performed when deadlocks are detected.
config - the transaction configuration used for calling - Environment.beginTransaction(com.sleepycat.db.Transaction, com.sleepycat.db.TransactionConfig), or null to use the default +
+
+ + +
Constructor Detail
+ + + +
+
+
TransactionRunner
+
public TransactionRunner(Environment env)
+
Creates a transaction runner for a given Berkeley DB environment. + The default maximum number of retries (DEFAULT_MAX_RETRIES) and + a null (default) TransactionConfig will be used.
+
Parameters:
env - is the environment for running transactions.
+
+
+ + + +
+
+
TransactionRunner
+
public TransactionRunner(Environment env, + int maxRetries, + TransactionConfig config)
+
Creates a transaction runner for a given Berkeley DB environment and + with a given number of maximum retries.
+
Parameters:
env - is the environment for running transactions.
maxRetries - is the maximum number of retries that will be + performed when deadlocks are detected.
config - the transaction configuration used for calling + Environment.beginTransaction(com.sleepycat.db.Transaction, com.sleepycat.db.TransactionConfig), or null to use the default configuration. The configuration object is not cloned, and - any modifications to it will impact subsequent transactions.
-
- + any modifications to it will impact subsequent transactions.
+

+ + - - - - - - -

-Method Detail

- -

-getMaxRetries

-public int getMaxRetries()

Returns the maximum number of retries that will be performed when - deadlocks are detected. -

- -

-setMaxRetries

-public void setMaxRetries(int maxRetries)

Changes the maximum number of retries that will be performed when +

+ + +
Method Detail
+ + + +
- +
  getMaxRetries
  +
```
public int getMaxRetries()
```
  +
  Returns the maximum number of retries that will be performed when + deadlocks are detected.
  +
+ + + +
- +
  setMaxRetries
  +
```
public void setMaxRetries(int maxRetries)
```
  +
  Changes the maximum number of retries that will be performed when deadlocks are detected. - Calling this method does not impact transactions already running. -
  -
  -
  -
  -

- -

-getAllowNestedTransactions

-public boolean getAllowNestedTransactions()

Returns whether nested transactions will be created if + Calling this method does not impact transactions already running.

+ + + + + +

+
getAllowNestedTransactions
+
```
public boolean getAllowNestedTransactions()
```
+
Returns whether nested transactions will be created if run() is called when a transaction is already active for the current thread. By default this property is false.
Note that this method always returns false in the JE product, since - nested transactions are not supported by JE.
-
-
-
-
- -
- -
-setAllowNestedTransactions
-
```
-public void setAllowNestedTransactions(boolean allowNestedTxn)
```
-
-
Changes whether nested transactions will be created if + nested transactions are not supported by JE.
+

+ + + +

+
setAllowNestedTransactions
+
```
public void setAllowNestedTransactions(boolean allowNestedTxn)
```
+
Changes whether nested transactions will be created if run() is called when a transaction is already active for the current thread. Calling this method does not impact transactions already running.
Note that true may not be passed to this method in the JE product, - since nested transactions are not supported by JE.
-
-
-
-
- -
- -
-getTransactionConfig
-
```
-public TransactionConfig getTransactionConfig()
```
-
-
Returns the transaction configuration used for calling - Environment.beginTransaction(com.sleepycat.db.Transaction, com.sleepycat.db.TransactionConfig). + since nested transactions are not supported by JE.
+

+ + + +

+
getTransactionConfig
+
```
public TransactionConfig getTransactionConfig()
```
+
Returns the transaction configuration used for calling + Environment.beginTransaction(com.sleepycat.db.Transaction, com.sleepycat.db.TransactionConfig).
If this property is null, the default configuration is used. The configuration object is not cloned, and any modifications to it will - impact subsequent transactions.
-
-
- -
Returns:
the transaction configuration.
-
- -
- -
-setTransactionConfig
-
```
-public void setTransactionConfig(TransactionConfig config)
```
-
-
Changes the transaction configuration used for calling - Environment.beginTransaction(com.sleepycat.db.Transaction, com.sleepycat.db.TransactionConfig). + impact subsequent transactions.
+
Returns:
the transaction configuration.
+

+ + + +

+
setTransactionConfig
+
```
public void setTransactionConfig(TransactionConfig config)
```
+
Changes the transaction configuration used for calling + Environment.beginTransaction(com.sleepycat.db.Transaction, com.sleepycat.db.TransactionConfig).
If this property is null, the default configuration is used. The configuration object is not cloned, and any modifications to it will - impact subsequent transactions.
-
-
-
Parameters:
config - the transaction configuration.
-
- -
- -
-run
-
```
-public void run(TransactionWorker worker)
-         throws DatabaseException,
-                Exception
```
-
-
Calls the TransactionWorker.doWork() method and, for transactional + impact subsequent transactions.
+
Parameters:
config - the transaction configuration.
+

+ + + +

+
run
+
```
public void run(TransactionWorker worker)
+         throws DatabaseException,
+                java.lang.Exception
```
+
Calls the TransactionWorker.doWork() method and, for transactional environments, may begin and end a transaction. If the environment given is non-transactional, a transaction will not be used but the doWork() method will still be called. See the class description for more - information. -
-
- -
Throws: -
DeadlockException - when it is thrown by doWork() and the + information.
+
Throws:
+
DeadlockException - when it is thrown by doWork() and the maximum number of retries has occurred. The transaction will have been - aborted by this method. -
Exception - when any other exception is thrown by doWork(). The - exception will first be unwrapped by calling ExceptionUnwrapper.unwrap(java.lang.Exception). The transaction will have been aborted by - this method. -
DatabaseException
- - -
- -
-handleException
-
```
-public int handleException(Exception exception,
-                           int retries,
-                           int maxRetries)
-                    throws Exception
```
-
-
Handles exceptions that occur during a transaction, and may implement - transaction retry policy. The transaction is aborted by the run method before calling this method. - -
The default implementation of this method throws the exception parameter if it is not an instance of DeadlockException and otherwise returns the maxRetries + aborted by this method.
+
java.lang.Exception - when any other exception is thrown by doWork(). The + exception will first be unwrapped by calling ExceptionUnwrapper.unwrap(java.lang.Exception). The transaction will have been aborted by + this method.
+
DatabaseException
+

+ + + +

+
handleException
+
```
public int handleException(java.lang.Exception exception,
+                  int retries,
+                  int maxRetries)
+                    throws java.lang.Exception
```
+
Handles exceptions that occur during a transaction, and may implement + transaction retry policy. The transaction is aborted by the run method before calling this method. + +
The default implementation of this method throws the exception parameter if it is not an instance of DeadlockException and otherwise returns the maxRetries parameter value. This method can be overridden to throw a different exception or return a different number of retries. For example:
-
-
-
Parameters:
exception - an exception that was thrown by the TransactionWorker.doWork() method or thrown when beginning or committing + a DeadlockException occurs, to override the default behavior + which is to throw the DeadlockException.

- -com.sleepycat.collections -
-Class TransactionRunner

Class TransactionRunner

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

-DEFAULT_MAX_RETRIES

Field Detail

DEFAULT_MAX_RETRIES