/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
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package org.springframework.transaction.annotation;

import org.springframework.transaction.TransactionDefinition;

Enumeration that represents transaction isolation levels for use with the Transactional annotation, corresponding to the TransactionDefinition interface. 
Author:
Colin Sampaleanu, Juergen Hoeller
Since:
1.2/**
 * Enumeration that represents transaction isolation levels for use
 * with the {@link Transactional} annotation, corresponding to the
 * {@link TransactionDefinition} interface.
 *
 * @author Colin Sampaleanu
 * @author Juergen Hoeller
 * @since 1.2
 */
public enum Isolation {

	
Use the default isolation level of the underlying datastore.
All other levels correspond to the JDBC isolation levels.
See Also:
Connection/**
	 * Use the default isolation level of the underlying datastore.
	 * All other levels correspond to the JDBC isolation levels.
	 * @see java.sql.Connection
	 */
	DEFAULT(TransactionDefinition.ISOLATION_DEFAULT),

	
A constant indicating that dirty reads, non-repeatable reads and phantom reads
can occur. This level allows a row changed by one transaction to be read by
another transaction before any changes in that row have been committed
(a "dirty read"). If any of the changes are rolled back, the second
transaction will have retrieved an invalid row.
See Also:
TRANSACTION_READ_UNCOMMITTED.TRANSACTION_READ_UNCOMMITTED/**
	 * A constant indicating that dirty reads, non-repeatable reads and phantom reads
	 * can occur. This level allows a row changed by one transaction to be read by
	 * another transaction before any changes in that row have been committed
	 * (a "dirty read"). If any of the changes are rolled back, the second
	 * transaction will have retrieved an invalid row.
	 * @see java.sql.Connection#TRANSACTION_READ_UNCOMMITTED
	 */
	READ_UNCOMMITTED(TransactionDefinition.ISOLATION_READ_UNCOMMITTED),

	
A constant indicating that dirty reads are prevented; non-repeatable reads
and phantom reads can occur. This level only prohibits a transaction
from reading a row with uncommitted changes in it.
See Also:
TRANSACTION_READ_COMMITTED.TRANSACTION_READ_COMMITTED/**
	 * A constant indicating that dirty reads are prevented; non-repeatable reads
	 * and phantom reads can occur. This level only prohibits a transaction
	 * from reading a row with uncommitted changes in it.
	 * @see java.sql.Connection#TRANSACTION_READ_COMMITTED
	 */
	READ_COMMITTED(TransactionDefinition.ISOLATION_READ_COMMITTED),

	
A constant indicating that dirty reads and non-repeatable reads are
prevented; phantom reads can occur. This level prohibits a transaction
from reading a row with uncommitted changes in it, and it also prohibits
the situation where one transaction reads a row, a second transaction
alters the row, and the first transaction rereads the row, getting
different values the second time (a "non-repeatable read").
See Also:
TRANSACTION_REPEATABLE_READ.TRANSACTION_REPEATABLE_READ/**
	 * A constant indicating that dirty reads and non-repeatable reads are
	 * prevented; phantom reads can occur. This level prohibits a transaction
	 * from reading a row with uncommitted changes in it, and it also prohibits
	 * the situation where one transaction reads a row, a second transaction
	 * alters the row, and the first transaction rereads the row, getting
	 * different values the second time (a "non-repeatable read").
	 * @see java.sql.Connection#TRANSACTION_REPEATABLE_READ
	 */
	REPEATABLE_READ(TransactionDefinition.ISOLATION_REPEATABLE_READ),

	
A constant indicating that dirty reads, non-repeatable reads and phantom reads are prevented. This level includes the prohibitions in ISOLATION_REPEATABLE_READ and further prohibits the situation where one transaction reads all rows that satisfy a WHERE condition, a second transaction inserts a row that satisfies that WHERE condition, and the first transaction rereads for the same condition, retrieving the additional "phantom" row in the second read. 
See Also:
Connection.TRANSACTION_SERIALIZABLE/**
	 * A constant indicating that dirty reads, non-repeatable reads and phantom
	 * reads are prevented. This level includes the prohibitions in
	 * {@code ISOLATION_REPEATABLE_READ} and further prohibits the situation
	 * where one transaction reads all rows that satisfy a {@code WHERE}
	 * condition, a second transaction inserts a row that satisfies that
	 * {@code WHERE} condition, and the first transaction rereads for the
	 * same condition, retrieving the additional "phantom" row in the second read.
	 * @see java.sql.Connection#TRANSACTION_SERIALIZABLE
	 */
	SERIALIZABLE(TransactionDefinition.ISOLATION_SERIALIZABLE);


	private final int value;


	Isolation(int value) {
		this.value = value;
	}

	public int value() {
		return this.value;
	}

}