namematchtransactionattributesource.java

一个关于Spring框架的示例应用程序,简单使用,可以参考.

/*
 * Copyright 2002-2004 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.
 */

package org.springframework.transaction.interceptor;

import java.io.Serializable;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Properties;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * Simple implementation of TransactionAttributeSource that
 * allows attributes to be matched by registered name.
 * @author Juergen Hoeller
 * @since 21.08.2003
 * @see #isMatch
 * @see MethodMapTransactionAttributeSource
 */
public class NameMatchTransactionAttributeSource implements TransactionAttributeSource, Serializable {

	/** Static for optimal serialization */
	protected static final Log logger = LogFactory.getLog(NameMatchTransactionAttributeSource.class);

	/** Keys are method names; values are TransactionAttributes */
	private Map nameMap = new HashMap();


	/**
	 * Set a name/attribute map, consisting of method names
	 * (e.g. "myMethod") and TransactionAttribute instances
	 * (or Strings to be converted to TransactionAttribute instances).
	 * @see TransactionAttribute
	 * @see TransactionAttributeEditor
	 */
	public void setNameMap(Map nameMap) {
		Iterator it = nameMap.entrySet().iterator();
		while (it.hasNext()) {
			Map.Entry entry = (Map.Entry) it.next();
			String name = (String) entry.getKey();

			// Check whether we need to convert from String to TransactionAttribute.
			TransactionAttribute attr = null;
			if (entry.getValue() instanceof TransactionAttribute) {
				attr = (TransactionAttribute) entry.getValue();
			}
			else {
				TransactionAttributeEditor editor = new TransactionAttributeEditor();
				editor.setAsText(entry.getValue().toString());
				attr = (TransactionAttribute) editor.getValue();
			}

			addTransactionalMethod(name, attr);
		}
	}

	/**
	 * Parses the given properties into a name/attribute map.
	 * Expects method names as keys and String attributes definitions as values,
	 * parsable into TransactionAttribute instances via TransactionAttributeEditor.
	 * @see #setNameMap
	 * @see TransactionAttributeEditor
	 */
	public void setProperties(Properties transactionAttributes) {
		TransactionAttributeEditor tae = new TransactionAttributeEditor();
		for (Iterator it = transactionAttributes.keySet().iterator(); it.hasNext(); ) {
			String methodName = (String) it.next();
			String value = transactionAttributes.getProperty(methodName);
			tae.setAsText(value);
			TransactionAttribute attr = (TransactionAttribute) tae.getValue();
			addTransactionalMethod(methodName, attr);
		}
	}

	/**
	 * Add an attribute for a transactional method.
	 * Method names can end with "*" for matching multiple methods.
	 * @param methodName the name of the method
	 * @param attr attribute associated with the method
	 */
	public void addTransactionalMethod(String methodName, TransactionAttribute attr) {
		if (logger.isDebugEnabled()) {
			logger.debug("Adding transactional method [" + methodName + "] with attribute [" + attr + "]");
		}
		this.nameMap.put(methodName, attr);
	}


	public TransactionAttribute getTransactionAttribute(Method method, Class targetClass) {
		// look for direct name match
		String methodName = method.getName();
		TransactionAttribute attr = (TransactionAttribute) this.nameMap.get(methodName);

		if (attr == null) {
			// look for most specific name match
			String bestNameMatch = null;
			for (Iterator it = this.nameMap.keySet().iterator(); it.hasNext();) {
				String mappedName = (String) it.next();
				if (isMatch(methodName, mappedName) &&
						(bestNameMatch == null || bestNameMatch.length() <= mappedName.length())) {
					attr = (TransactionAttribute) this.nameMap.get(mappedName);
					bestNameMatch = mappedName;
				}
			}
		}

		return attr;
	}

	/**
	 * Return if the given method name matches the mapped name.
	 * The default implementation checks for "xxx*" and "*xxx" matches.
	 * Can be overridden in subclasses.
	 * @param methodName the method name of the class
	 * @param mappedName the name in the descriptor
	 * @return if the names match
	 */
	protected boolean isMatch(String methodName, String mappedName) {
		return (mappedName.endsWith("*") && methodName.startsWith(mappedName.substring(0, mappedName.length() - 1))) ||
				(mappedName.startsWith("*") && methodName.endsWith(mappedName.substring(1, mappedName.length())));
	}

}