| /* |
| * Copyright 1999-2004 The Apache Software Foundation. |
| * |
| * 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.apache.cocoon.components.modules.output; |
| |
| import org.apache.avalon.framework.configuration.Configuration; |
| import org.apache.avalon.framework.thread.ThreadSafe; |
| |
| import org.apache.cocoon.environment.ObjectModelHelper; |
| import org.apache.cocoon.environment.Request; |
| |
| import java.util.Iterator; |
| import java.util.Map; |
| |
| /** |
| * Abstraction layer to encapsulate different output |
| * destinations. Configuration option <key-prefix> defaults to |
| * <code>"org.apache.cocoon.components.modules.output.OutputModule" + ":"</code> |
| * |
| * <p>Can be used with different isolation-level: default is "0" being |
| * no isolation at all, values are immediately visible but are removed |
| * on a rollback; "1" keeps the values at a safe place until either |
| * rollback or commit is called. Then values are either discarded or |
| * copied to the final destination.</p> |
| * |
| * @version $Id$ |
| */ |
| public class RequestAttributeOutputModule extends AbstractOutputModule implements OutputModule, ThreadSafe { |
| |
| public static final String PREFIX = OutputModule.ROLE; |
| public static final String TRANS_PREFIX = PREFIX + ".RequestAttributeOutputModule.transient"; |
| public static final String ROLLBACK_LIST = PREFIX + ".RequestAttributeOutputModule.rollback"; |
| |
| /** |
| * communicate an attribute value to further processing logic. |
| * @param modeConf column's mode configuration from resource |
| * description. This argument is optional. |
| * @param objectModel The objectModel |
| * @param name The attribute's label, consisting of "table.column" |
| * or "table.column[index]" in case of multiple attributes |
| * of the same spec. |
| * @param value The attriute's value. |
| */ |
| public void setAttribute(Configuration modeConf, Map objectModel, String name, Object value) { |
| if (this.settings.get("isolation-level", "0").equals("1")) { |
| // Read committed isolation level |
| if (getLogger().isDebugEnabled()) { |
| getLogger().debug("Setting transient ['" + name + "'] to ['" + value + "']"); |
| } |
| transientSetAttribute(objectModel, TRANS_PREFIX, name, value); |
| } else { |
| // Read uncommitted isolation level |
| final Request request = ObjectModelHelper.getRequest(objectModel); |
| |
| name = getName(name); |
| |
| if (!attributeExists(objectModel, ROLLBACK_LIST, name)) { |
| Object tmp = request.getAttribute(name); |
| transientSetAttribute(objectModel, ROLLBACK_LIST, name, tmp); |
| } |
| |
| if (getLogger().isDebugEnabled()) { |
| getLogger().debug("Setting ['" + name + "'] to ['" + value + "']"); |
| } |
| request.setAttribute(name, value); |
| } |
| } |
| |
| /** |
| * If a database transaction needs to rollback, this is called to |
| * inform the further processing logic about this fact. All |
| * already set attribute values are invalidated. |
| * |
| * <em>This is difficult |
| * because only the request object can be used to synchronize this |
| * and build some kind of transaction object. Beware that sending |
| * your data straight to some beans or other entities could result |
| * in data corruption!</em> |
| */ |
| public void rollback(Configuration modeConf, Map objectModel, Exception e) { |
| getLogger().debug("Rollback"); |
| final Request request = ObjectModelHelper.getRequest(objectModel); |
| |
| if (this.settings.get("isolation-level", "0").equals("1")) { |
| rollback(objectModel, TRANS_PREFIX); |
| } else { |
| Map rollbackList = prepareCommit(objectModel, ROLLBACK_LIST); |
| if (rollbackList != null) { |
| for (Iterator i = rollbackList.entrySet().iterator(); i.hasNext();) { |
| final Map.Entry me = (Map.Entry) i.next(); |
| String key = (String) me.getKey(); |
| Object val = me.getValue(); |
| if (val != null) { |
| if (getLogger().isDebugEnabled()) { |
| getLogger().debug("Rolling back ['" + key + "'] to ['" + val + "']"); |
| } |
| request.setAttribute(key, val); |
| } else { |
| if (getLogger().isDebugEnabled()) { |
| getLogger().debug("Rolling back ['" + key + "']"); |
| } |
| request.removeAttribute(key); |
| } |
| } |
| } |
| } |
| |
| String prefix = (String) this.settings.get("key-prefix", PREFIX); |
| if (prefix.equals("")) { |
| request.setAttribute("errorMessage", e.getMessage()); |
| } else { |
| request.setAttribute(prefix + ':' + "errorMessage", e.getMessage()); |
| } |
| } |
| |
| /** |
| * Signal that the database transaction completed |
| * successfully. See notes on @link{rollback}. |
| */ |
| public void commit(Configuration modeConf, Map objectModel) { |
| getLogger().debug("Commit"); |
| if (this.settings.get("isolation-level", "0").equals("1")) { |
| Map data = prepareCommit(objectModel, TRANS_PREFIX); |
| if (data == null || data.isEmpty()) { |
| return; |
| } |
| |
| String prefix = (String) this.settings.get("key-prefix", PREFIX); |
| if (prefix.length() == 0) { |
| prefix = null; |
| } |
| |
| Request request = ObjectModelHelper.getRequest(objectModel); |
| for (Iterator i = data.entrySet().iterator(); i.hasNext();) { |
| final Map.Entry me = (Map.Entry) i.next(); |
| String key = (String) me.getKey(); |
| Object value = me.getValue(); |
| if (prefix != null) { |
| key = prefix + ':' + key; |
| } |
| if (getLogger().isDebugEnabled()) { |
| getLogger().debug("Committing ['" + key + "'] to ['" + value + "']"); |
| } |
| request.setAttribute(key, value); |
| } |
| } else { |
| prepareCommit(objectModel, ROLLBACK_LIST); |
| } |
| |
| |
| } |
| |
| protected String getName(String name) { |
| String prefix = (String) this.settings.get("key-prefix", PREFIX); |
| return prefix.equals("") ? name : prefix + ':' + name; |
| } |
| } |