https://github.com/spring-projects/spring-framework: Spring Transaction (Spring IO)
  • Juergen Hoeller 
/*
 * 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
 *
 *      https://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.
 */

package org.springframework.transaction.jta;

import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import javax.transaction.InvalidTransactionException;
import javax.transaction.NotSupportedException;
import javax.transaction.SystemException;
import javax.transaction.Transaction;
import javax.transaction.TransactionManager;
import javax.transaction.UserTransaction;

import org.springframework.lang.Nullable;
import org.springframework.transaction.TransactionDefinition;
import org.springframework.transaction.TransactionSystemException;
import org.springframework.util.Assert;


Special JtaTransactionManager variant for BEA WebLogic (9.0 and higher). Supports the full power of Spring's transaction definitions on WebLogic's transaction coordinator, beyond standard JTA: transaction names,
per-transaction isolation levels, and proper resuming of transactions in all cases.

Uses WebLogic's special begin(name) method to start a JTA transaction, in order to make Spring-driven transactions visible in WebLogic's transaction
monitor. In case of Spring's declarative transactions, the exposed name will
(by default) be the fully-qualified class name + "." + method name.

Supports a per-transaction isolation level through WebLogic's corresponding
JTA transaction property "ISOLATION LEVEL". This will apply the specified isolation
level (e.g. ISOLATION_SERIALIZABLE) to all JDBC Connections that participate in the
given transaction.

Invokes WebLogic's special forceResume method if standard JTA resume failed, to also resume if the target transaction was marked rollback-only.
If you're not relying on this feature of transaction suspension in the first
place, Spring's standard JtaTransactionManager will behave properly too.

By default, the JTA UserTransaction and TransactionManager handles are fetched directly from WebLogic's TransactionHelper. This can be overridden by specifying "userTransaction"/"userTransactionName" and "transactionManager"/"transactionManagerName", passing in existing handles or specifying corresponding JNDI locations to look up. 
NOTE: This JtaTransactionManager is intended to refine specific transaction
demarcation behavior on Spring's side. It will happily co-exist with independently
configured WebLogic transaction strategies in your persistence provider, with no
need to specifically connect those setups in any way.

Author:Juergen Hoeller
See Also:
Since:1.1
/**
 * Special {@link JtaTransactionManager} variant for BEA WebLogic (9.0 and higher).
 * Supports the full power of Spring's transaction definitions on WebLogic's
 * transaction coordinator, <i>beyond standard JTA</i>: transaction names,
 * per-transaction isolation levels, and proper resuming of transactions in all cases.
 *
 * <p>Uses WebLogic's special {@code begin(name)} method to start a JTA transaction,
 * in order to make <b>Spring-driven transactions visible in WebLogic's transaction
 * monitor</b>. In case of Spring's declarative transactions, the exposed name will
 * (by default) be the fully-qualified class name + "." + method name.
 *
 * <p>Supports a <b>per-transaction isolation level</b> through WebLogic's corresponding
 * JTA transaction property "ISOLATION LEVEL". This will apply the specified isolation
 * level (e.g. ISOLATION_SERIALIZABLE) to all JDBC Connections that participate in the
 * given transaction.
 *
 * <p>Invokes WebLogic's special {@code forceResume} method if standard JTA resume
 * failed, to <b>also resume if the target transaction was marked rollback-only</b>.
 * If you're not relying on this feature of transaction suspension in the first
 * place, Spring's standard JtaTransactionManager will behave properly too.
 *
 * <p>By default, the JTA UserTransaction and TransactionManager handles are
 * fetched directly from WebLogic's {@code TransactionHelper}. This can be
 * overridden by specifying "userTransaction"/"userTransactionName" and
 * "transactionManager"/"transactionManagerName", passing in existing handles
 * or specifying corresponding JNDI locations to look up.
 *
 * <p><b>NOTE: This JtaTransactionManager is intended to refine specific transaction
 * demarcation behavior on Spring's side. It will happily co-exist with independently
 * configured WebLogic transaction strategies in your persistence provider, with no
 * need to specifically connect those setups in any way.</b>
 *
 * @author Juergen Hoeller
 * @since 1.1
 * @see org.springframework.transaction.TransactionDefinition#getName
 * @see org.springframework.transaction.TransactionDefinition#getIsolationLevel
 * @see weblogic.transaction.UserTransaction#begin(String)
 * @see weblogic.transaction.Transaction#setProperty
 * @see weblogic.transaction.TransactionManager#forceResume
 * @see weblogic.transaction.TransactionHelper
 */
@SuppressWarnings("serial")
public class WebLogicJtaTransactionManager extends JtaTransactionManager {

	private static final String USER_TRANSACTION_CLASS_NAME = "weblogic.transaction.UserTransaction";

	private static final String CLIENT_TRANSACTION_MANAGER_CLASS_NAME = "weblogic.transaction.ClientTransactionManager";

	private static final String TRANSACTION_CLASS_NAME = "weblogic.transaction.Transaction";

	private static final String TRANSACTION_HELPER_CLASS_NAME = "weblogic.transaction.TransactionHelper";

	private static final String ISOLATION_LEVEL_KEY = "ISOLATION LEVEL";


	private boolean weblogicUserTransactionAvailable;

	@Nullable
	private Method beginWithNameMethod;

	@Nullable
	private Method beginWithNameAndTimeoutMethod;

	private boolean weblogicTransactionManagerAvailable;

	@Nullable
	private Method forceResumeMethod;

	@Nullable
	private Method setPropertyMethod;

	@Nullable
	private Object transactionHelper;


	@Override
	public void afterPropertiesSet() throws TransactionSystemException {
		super.afterPropertiesSet();
		loadWebLogicTransactionClasses();
	}

	@Override
	@Nullable
	protected UserTransaction retrieveUserTransaction() throws TransactionSystemException {
		Object helper = loadWebLogicTransactionHelper();
		try {
			logger.trace("Retrieving JTA UserTransaction from WebLogic TransactionHelper");
			Method getUserTransactionMethod = helper.getClass().getMethod("getUserTransaction");
			return (UserTransaction) getUserTransactionMethod.invoke(this.transactionHelper);
		}
		catch (InvocationTargetException ex) {
			throw new TransactionSystemException(
					"WebLogic's TransactionHelper.getUserTransaction() method failed", ex.getTargetException());
		}
		catch (Exception ex) {
			throw new TransactionSystemException(
					"Could not invoke WebLogic's TransactionHelper.getUserTransaction() method", ex);
		}
	}

	@Override
	@Nullable
	protected TransactionManager retrieveTransactionManager() throws TransactionSystemException {
		Object helper = loadWebLogicTransactionHelper();
		try {
			logger.trace("Retrieving JTA TransactionManager from WebLogic TransactionHelper");
			Method getTransactionManagerMethod = helper.getClass().getMethod("getTransactionManager");
			return (TransactionManager) getTransactionManagerMethod.invoke(this.transactionHelper);
		}
		catch (InvocationTargetException ex) {
			throw new TransactionSystemException(
					"WebLogic's TransactionHelper.getTransactionManager() method failed", ex.getTargetException());
		}
		catch (Exception ex) {
			throw new TransactionSystemException(
					"Could not invoke WebLogic's TransactionHelper.getTransactionManager() method", ex);
		}
	}

	private Object loadWebLogicTransactionHelper() throws TransactionSystemException {
		Object helper = this.transactionHelper;
		if (helper == null) {
			try {
				Class<?> transactionHelperClass = getClass().getClassLoader().loadClass(TRANSACTION_HELPER_CLASS_NAME);
				Method getTransactionHelperMethod = transactionHelperClass.getMethod("getTransactionHelper");
				helper = getTransactionHelperMethod.invoke(null);
				this.transactionHelper = helper;
				logger.trace("WebLogic TransactionHelper found");
			}
			catch (InvocationTargetException ex) {
				throw new TransactionSystemException(
						"WebLogic's TransactionHelper.getTransactionHelper() method failed", ex.getTargetException());
			}
			catch (Exception ex) {
				throw new TransactionSystemException(
						"Could not initialize WebLogicJtaTransactionManager because WebLogic API classes are not available",
						ex);
			}
		}
		return helper;
	}

	private void loadWebLogicTransactionClasses() throws TransactionSystemException {
		try {
			Class<?> userTransactionClass = getClass().getClassLoader().loadClass(USER_TRANSACTION_CLASS_NAME);
			this.weblogicUserTransactionAvailable = userTransactionClass.isInstance(getUserTransaction());
			if (this.weblogicUserTransactionAvailable) {
				this.beginWithNameMethod = userTransactionClass.getMethod("begin", String.class);
				this.beginWithNameAndTimeoutMethod = userTransactionClass.getMethod("begin", String.class, int.class);
				logger.debug("Support for WebLogic transaction names available");
			}
			else {
				logger.debug("Support for WebLogic transaction names not available");
			}

			// Obtain WebLogic ClientTransactionManager interface.
			Class<?> transactionManagerClass =
					getClass().getClassLoader().loadClass(CLIENT_TRANSACTION_MANAGER_CLASS_NAME);
			logger.trace("WebLogic ClientTransactionManager found");

			this.weblogicTransactionManagerAvailable = transactionManagerClass.isInstance(getTransactionManager());
			if (this.weblogicTransactionManagerAvailable) {
				Class<?> transactionClass = getClass().getClassLoader().loadClass(TRANSACTION_CLASS_NAME);
				this.forceResumeMethod = transactionManagerClass.getMethod("forceResume", Transaction.class);
				this.setPropertyMethod = transactionClass.getMethod("setProperty", String.class, Serializable.class);
				logger.debug("Support for WebLogic forceResume available");
			}
			else {
				logger.debug("Support for WebLogic forceResume not available");
			}
		}
		catch (Exception ex) {
			throw new TransactionSystemException(
					"Could not initialize WebLogicJtaTransactionManager because WebLogic API classes are not available",
					ex);
		}
	}

	private TransactionManager obtainTransactionManager() {
		TransactionManager tm = getTransactionManager();
		Assert.state(tm != null, "No TransactionManager set");
		return tm;
	}


	@Override
	protected void doJtaBegin(JtaTransactionObject txObject, TransactionDefinition definition)
			throws NotSupportedException, SystemException {

		int timeout = determineTimeout(definition);

		// Apply transaction name (if any) to WebLogic transaction.
		if (this.weblogicUserTransactionAvailable && definition.getName() != null) {
			try {
				if (timeout > TransactionDefinition.TIMEOUT_DEFAULT) {
					/*
					weblogic.transaction.UserTransaction wut = (weblogic.transaction.UserTransaction) ut;
					wut.begin(definition.getName(), timeout);
					*/
					Assert.state(this.beginWithNameAndTimeoutMethod != null, "WebLogic JTA API not initialized");
					this.beginWithNameAndTimeoutMethod.invoke(txObject.getUserTransaction(), definition.getName(), timeout);
				}
				else {
					/*
					weblogic.transaction.UserTransaction wut = (weblogic.transaction.UserTransaction) ut;
					wut.begin(definition.getName());
					*/
					Assert.state(this.beginWithNameMethod != null, "WebLogic JTA API not initialized");
					this.beginWithNameMethod.invoke(txObject.getUserTransaction(), definition.getName());
				}
			}
			catch (InvocationTargetException ex) {
				throw new TransactionSystemException(
						"WebLogic's UserTransaction.begin() method failed", ex.getTargetException());
			}
			catch (Exception ex) {
				throw new TransactionSystemException(
						"Could not invoke WebLogic's UserTransaction.begin() method", ex);
			}
		}
		else {
			// No WebLogic UserTransaction available or no transaction name specified
			// -> standard JTA begin call.
			applyTimeout(txObject, timeout);
			txObject.getUserTransaction().begin();
		}

		// Specify isolation level, if any, through corresponding WebLogic transaction property.
		if (this.weblogicTransactionManagerAvailable) {
			if (definition.getIsolationLevel() != TransactionDefinition.ISOLATION_DEFAULT) {
				try {
					Transaction tx = obtainTransactionManager().getTransaction();
					Integer isolationLevel = definition.getIsolationLevel();
					/*
					weblogic.transaction.Transaction wtx = (weblogic.transaction.Transaction) tx;
					wtx.setProperty(ISOLATION_LEVEL_KEY, isolationLevel);
					*/
					Assert.state(this.setPropertyMethod != null, "WebLogic JTA API not initialized");
					this.setPropertyMethod.invoke(tx, ISOLATION_LEVEL_KEY, isolationLevel);
				}
				catch (InvocationTargetException ex) {
					throw new TransactionSystemException(
							"WebLogic's Transaction.setProperty(String, Serializable) method failed", ex.getTargetException());
				}
				catch (Exception ex) {
					throw new TransactionSystemException(
							"Could not invoke WebLogic's Transaction.setProperty(String, Serializable) method", ex);
				}
			}
		}
		else {
			applyIsolationLevel(txObject, definition.getIsolationLevel());
		}
	}

	@Override
	protected void doJtaResume(@Nullable JtaTransactionObject txObject, Object suspendedTransaction)
			throws InvalidTransactionException, SystemException {

		try {
			obtainTransactionManager().resume((Transaction) suspendedTransaction);
		}
		catch (InvalidTransactionException ex) {
			if (!this.weblogicTransactionManagerAvailable) {
				throw ex;
			}

			if (logger.isDebugEnabled()) {
				logger.debug("Standard JTA resume threw InvalidTransactionException: " + ex.getMessage() +
					" - trying WebLogic JTA forceResume");
			}
			/*
			weblogic.transaction.TransactionManager wtm =
					(weblogic.transaction.TransactionManager) getTransactionManager();
			wtm.forceResume(suspendedTransaction);
			*/
			try {
				Assert.state(this.forceResumeMethod != null, "WebLogic JTA API not initialized");
				this.forceResumeMethod.invoke(getTransactionManager(), suspendedTransaction);
			}
			catch (InvocationTargetException ex2) {
				throw new TransactionSystemException(
						"WebLogic's TransactionManager.forceResume(Transaction) method failed", ex2.getTargetException());
			}
			catch (Exception ex2) {
				throw new TransactionSystemException(
						"Could not access WebLogic's TransactionManager.forceResume(Transaction) method", ex2);
			}
		}
	}

	@Override
	public Transaction createTransaction(@Nullable String name, int timeout) throws NotSupportedException, SystemException {
		if (this.weblogicUserTransactionAvailable && name != null) {
			try {
				if (timeout >= 0) {
					Assert.state(this.beginWithNameAndTimeoutMethod != null, "WebLogic JTA API not initialized");
					this.beginWithNameAndTimeoutMethod.invoke(getUserTransaction(), name, timeout);
				}
				else {
					Assert.state(this.beginWithNameMethod != null, "WebLogic JTA API not initialized");
					this.beginWithNameMethod.invoke(getUserTransaction(), name);
				}
			}
			catch (InvocationTargetException ex) {
				if (ex.getTargetException() instanceof NotSupportedException) {
					throw (NotSupportedException) ex.getTargetException();
				}
				else if (ex.getTargetException() instanceof SystemException) {
					throw (SystemException) ex.getTargetException();
				}
				else if (ex.getTargetException() instanceof RuntimeException) {
					throw (RuntimeException) ex.getTargetException();
				}
				else {
					throw new SystemException(
							"WebLogic's begin() method failed with an unexpected error: " + ex.getTargetException());
				}
			}
			catch (Exception ex) {
				throw new SystemException("Could not invoke WebLogic's UserTransaction.begin() method: " + ex);
			}
			return new ManagedTransactionAdapter(obtainTransactionManager());
		}

		else {
			// No name specified - standard JTA is sufficient.
			return super.createTransaction(name, timeout);
		}
	}

}