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// Copyright (c) 2003-present, Jodd Team (http://jodd.org)
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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package jodd.db;
import jodd.db.connection.ConnectionProvider;
import jodd.log.Logger;
import jodd.log.LoggerFactory;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.HashSet;
import java.util.Set;
/**
* Encapsulates db connection. Initially works in auto-commit mode.
* May start and work with transactions, after committing/rolling back
* DbSession goes back to auto-commit mode.
*
* All invoked queries are stored within one session and closed implicitly
* on session closing.
*
* For managed transaction see DbJtxTransactionManager from jodd-tx.
*/
public class DbSession implements AutoCloseable {
private static final Logger log = LoggerFactory.getLogger(DbSession.class);
// ---------------------------------------------------------------- init & close
protected final ConnectionProvider connectionProvider;
protected Connection connection;
/**
* Creates new database session with default transaction mode and in autocommit mode.
*/
public DbSession(ConnectionProvider connectionProvider) {
log.debug("Creating new db session");
if (connectionProvider == null) {
connectionProvider = DbOom.get().connectionProvider();
if (connectionProvider == null) {
throw new DbSqlException("Connection provider is not available");
}
}
this.connectionProvider = connectionProvider;
this.txActive = false;
this.txMode = DbTransactionMode.READ_ONLY_TX;
this.queries = new HashSet<>();
}
/**
* Closes current session and all allocated resources.
* All attached queries are closed. If a transaction is still active, exception occurs.
* Database connection is returned to the {@link ConnectionProvider}.
* Closed session is no longer available for usage.
*/
public void closeSession() {
log.debug("Closing db session");
SQLException sqlException = null;
if (queries != null) {
for (DbQueryBase query : queries) {
SQLException sex = query.closeQuery();
if (sex != null) {
if (sqlException == null) {
sqlException = sex;
} else {
sqlException.setNextException(sex);
}
}
}
}
if (connection != null) {
if (txActive) {
throw new DbSqlException("TX was not closed before closing the session");
}
connectionProvider.closeConnection(connection);
connection = null;
}
queries = null;
if (sqlException != null) {
throw new DbSqlException("Closing DbSession failed", sqlException);
}
}
@Override
public void close() {
closeSession();
}
/**
* Indicates whether a session is closed.
*/
public boolean isSessionClosed() {
return queries == null;
}
/**
* Returns true if session is open.
*/
public boolean isSessionOpen() {
return queries != null;
}
// ---------------------------------------------------------------- query
/**
* Bag of all queries attached to this session. Explicitly closed queries
* remains in the set. If null, session is closed.
* If not null, but empty, session is still considered as open.
*/
protected Set queries;
/**
* Returns total number of queries assigned to this session.
*/
public int getTotalQueries() {
if (queries == null) {
return 0;
}
return queries.size();
}
/**
* Returns current connection.
*/
public Connection getConnection() {
return connection;
}
/**
* Attaches a new {@link DbQuery}. May be invoked both inside and outside of transaction.
*/
protected void attachQuery(final DbQueryBase query) {
assertSessionIsOpen();
openConnectionForQuery();
queries.add(query);
}
/**
* Detach used {@link DbQuery}. Usually invoked by {@link jodd.db.DbQuery#close()}.
*/
protected void detachQuery(final DbQueryBase query) {
queries.remove(query);
}
/**
* Opens connection in auto-commit mode, if already not opened.
*/
protected void openConnectionForQuery() {
if (connection == null) {
connection = connectionProvider.getConnection();
txActive = false; // txAction should already be false
try {
connection.setAutoCommit(true);
} catch (SQLException sex) {
throw new DbSqlException("Failed to open non-TX connection", sex);
}
}
}
// ---------------------------------------------------------------- transaction
protected boolean txActive;
protected DbTransactionMode txMode;
/**
* Indicate whether a transaction is in progress.
*/
public boolean isTransactionActive() {
return txActive;
}
/**
* Opens a transaction.
*/
protected void openTx() {
if (connection == null) {
connection = connectionProvider.getConnection();
}
txActive = true;
try {
connection.setAutoCommit(false);
if (txMode.getIsolation() != DbTransactionMode.ISOLATION_DEFAULT) {
connection.setTransactionIsolation(txMode.getIsolation());
}
connection.setReadOnly(txMode.isReadOnly());
} catch (SQLException sex) {
throw new DbSqlException("Open TX failed", sex);
}
}
/**
* Closes current transaction.
*/
protected void closeTx() {
txActive = false;
try {
connection.setAutoCommit(true);
} catch (SQLException sex) {
throw new DbSqlException("Close TX failed", sex);
}
}
/**
* Starts a transaction.
*/
public void beginTransaction(final DbTransactionMode mode) {
log.debug("Beginning transaction");
assertTxIsClosed();
this.txMode = mode;
openTx();
}
/**
* Commit the current transaction, writing any unflushed changes to the database.
* Transaction mode is closed.
*/
public void commitTransaction() {
log.debug("Committing transaction");
assertTxIsActive();
try {
connection.commit();
} catch (SQLException sex) {
throw new DbSqlException("Commit TX failed", sex);
} finally {
closeTx();
}
}
/**
* Roll back the current transaction. Transaction mode is closed.
*/
public void rollbackTransaction() {
log.debug("Rolling-back transaction");
assertTxIsActive();
try {
connection.rollback();
} catch (SQLException sex) {
throw new DbSqlException("Rollback TX failed", sex);
} finally {
closeTx();
}
}
// ---------------------------------------------------------------- checking
protected void assertSessionIsOpen() {
if (queries == null) {
throw new DbSqlException("Session is closed");
}
}
protected void assertTxIsClosed() {
assertSessionIsOpen();
if (txActive) {
throw new DbSqlException("TX already started for this session");
}
}
protected void assertTxIsActive() {
assertSessionIsOpen();
if (!txActive) {
throw new DbSqlException("TX not available for this session");
}
}
}