com.holonplatform.jdbc.transaction

Enum TransactionIsolation

java.lang.Object

java.lang.Enum<TransactionIsolation>

com.holonplatform.jdbc.transaction.TransactionIsolation

All Implemented Interfaces:

Serializable, Comparable<TransactionIsolation>

public enum TransactionIsolation
extends Enum<TransactionIsolation>

Transaction isolation levels.

Since:

5.2.0

Enum Constant Summary

Enum Constants

Enum Constant and Description
NONE For engines that support it, none isolation means that each statement would essentially be its own transaction.
READ_COMMITTED Specifies that shared locks are held while the data is being read to avoid dirty reads, but the data can be changed before the end of the transaction, resulting in nonrepeatable reads or phantom data.
READ_UNCOMMITTED Implements dirty read, or isolation level 0 locking, which means that no shared locks are issued and no exclusive locks are honored.
REPEATABLE_READ Locks are placed on all data that is used in a query, preventing other users from updating the data, but new phantom rows can be inserted into the data set by another user and are included in later reads in the current transaction.
SERIALIZABLE Places a range lock on the data set, preventing other users from updating or inserting rows into the data set until the transaction is complete.

Method Summary

Modifier and Type	Method and Description
int	getLevel() Get transaction isolation level.
static TransactionIsolation	valueOf(String name) Returns the enum constant of this type with the specified name.
static TransactionIsolation[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

compareTo, equals, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

READ_UNCOMMITTED

public static final TransactionIsolation READ_UNCOMMITTED

Implements dirty read, or isolation level 0 locking, which means that no shared locks are issued and no exclusive locks are honored. When this option is set, it is possible to read uncommitted or dirty data; values in the data can be changed and rows can appear or disappear in the data set before the end of the transaction. This is the least restrictive of the four isolation levels.

READ_COMMITTED

public static final TransactionIsolation READ_COMMITTED

Specifies that shared locks are held while the data is being read to avoid dirty reads, but the data can be changed before the end of the transaction, resulting in nonrepeatable reads or phantom data.

REPEATABLE_READ

public static final TransactionIsolation REPEATABLE_READ

Locks are placed on all data that is used in a query, preventing other users from updating the data, but new phantom rows can be inserted into the data set by another user and are included in later reads in the current transaction. Because concurrency is lower than the default isolation level, use this option only when necessary.

SERIALIZABLE

public static final TransactionIsolation SERIALIZABLE

Places a range lock on the data set, preventing other users from updating or inserting rows into the data set until the transaction is complete. This is the most restrictive of the four isolation levels. Because concurrency is lower, use this option only when necessary.

NONE

public static final TransactionIsolation NONE

For engines that support it, none isolation means that each statement would essentially be its own transaction.

Method Detail

values

public static TransactionIsolation[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (TransactionIsolation c : TransactionIsolation.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static TransactionIsolation valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

getLevel

public int getLevel()

Get transaction isolation level.

Returns:

the transaction isolation level