001: /*
002: * JBoss, Home of Professional Open Source.
003: * Copyright 2006, Red Hat Middleware LLC, and individual contributors
004: * as indicated by the @author tags. See the copyright.txt file in the
005: * distribution for a full listing of individual contributors.
006: *
007: * This is free software; you can redistribute it and/or modify it
008: * under the terms of the GNU Lesser General Public License as
009: * published by the Free Software Foundation; either version 2.1 of
010: * the License, or (at your option) any later version.
011: *
012: * This software is distributed in the hope that it will be useful,
013: * but WITHOUT ANY WARRANTY; without even the implied warranty of
014: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015: * Lesser General Public License for more details.
016: *
017: * You should have received a copy of the GNU Lesser General Public
018: * License along with this software; if not, write to the Free
019: * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
020: * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
021: */
022: package org.jboss.ejb.plugins;
023:
024: import java.io.File;
025: import java.io.InputStream;
026: import java.io.OutputStream;
027: import java.io.ObjectInputStream;
028: import java.io.ObjectOutputStream;
029: import java.io.FileOutputStream;
030: import java.io.FileInputStream;
031: import java.io.BufferedOutputStream;
032: import java.io.BufferedInputStream;
033: import java.io.IOException;
034:
035: import java.lang.reflect.Method;
036: import java.lang.reflect.Field;
037:
038: import java.util.ArrayList;
039: import java.util.Collection;
040: import java.util.Collections;
041: import java.util.Iterator;
042:
043: import javax.ejb.EJBObject;
044: import javax.ejb.Handle;
045: import javax.ejb.CreateException;
046: import javax.ejb.DuplicateKeyException;
047: import javax.ejb.EJBException;
048: import javax.ejb.FinderException;
049: import javax.ejb.RemoveException;
050:
051: import org.jboss.ejb.Container;
052: import org.jboss.ejb.EntityContainer;
053: import org.jboss.ejb.EntityPersistenceStore;
054: import org.jboss.ejb.EntityEnterpriseContext;
055: import org.jboss.ejb.GenericEntityObjectFactory;
056: import org.jboss.metadata.EntityMetaData;
057:
058: import org.jboss.system.server.ServerConfigLocator;
059: import org.jboss.system.ServiceMBeanSupport;
060:
061: import org.jboss.util.file.FilenameSuffixFilter;
062:
063: /**
064: * A file-based CMP entity bean persistence manager.
065: *
066: * <p>
067: * Reads and writes entity bean objects to files by using the
068: * standard Java serialization mechanism.
069: *
070: * <p>
071: * Enitiy state files are stored under:
072: * <tt><em>jboss-server-data-dir</em>/<em>storeDirectoryName</em>/<em>ejb-name</em></tt>.
073: *
074: * <p>
075: * Note, currently the name of the entity must be unique across the server, or
076: * unless the store directory is changed, to avoid data collisions.
077: *
078: * <p>
079: * jason: disabled because XDoclet can not handle \u0000 right now
080: * _@_jmx:mbean extends="org.jboss.system.ServiceMBean"
081: *
082: * @version <tt>$Revision: 57209 $</tt>
083: * @author <a href="mailto:rickard.oberg@telkel.com">Rickard Öberg</a>
084: * @author <a href="mailto:marc.fleury@telkel.com">Marc Fleury</a>
085: * @author <a href="mailto:jason@planet57.com">Jason Dillon</a>
086: * <p><b>20010801 marc fleury:</b>
087: * <ul>
088: * <li>- insertion in cache upon create in now done in the instance interceptor
089: * </ul>
090: * <p><b>20011201 Dain Sundstrom:</b>
091: * <ul>
092: * <li>- added createBeanInstance and initEntity methods
093: * </ul>
094: * <p><b>20020525 Dain Sundstrom:</b>
095: * <ul>
096: * <li>- Replaced FinderResults with Collection
097: * <li>- Removed unused method loadEntities
098: * </ul>
099: */
100: public class CMPFilePersistenceManager extends ServiceMBeanSupport
101: implements EntityPersistenceStore /*, CMPFilePersistenceManagerMBean */
102: {
103: /** The default store directory name ("<tt>entities</tt>"). */
104: public static final String DEFAULT_STORE_DIRECTORY_NAME = "entities";
105:
106: /** Our container. */
107: private EntityContainer con;
108:
109: /**
110: * The sub-directory name under the server data directory where
111: * entity data is stored.
112: *
113: * @see #DEFAULT_STORE_DIRECTORY_NAME
114: */
115: private String storeDirName = DEFAULT_STORE_DIRECTORY_NAME;
116:
117: /** The base directory where bean state will be stored. */
118: private File storeDir;
119:
120: /** A reference to the ID field for the entiy bean. */
121: private Field idField;
122:
123: /** Optional isModified method used by storeEntity. */
124: private Method isModified;
125:
126: /**
127: * Saves a reference to the {@link EntityContainer} for
128: * its bean type.
129: *
130: * @throws ClassCastException Container is not a EntityContainer.
131: */
132: public void setContainer(final Container c) {
133: con = (EntityContainer) c;
134: }
135:
136: //
137: // jason: these properties are intended to be used when plugins/interceptors
138: // can take configuration values (need to update xml schema and processors).
139: //
140:
141: /**
142: * Set the sub-directory name under the server data directory
143: * where entity data will be stored.
144: *
145: * <p>
146: * This value will be appened to the value of
147: * <tt><em>jboss-server-data-dir</em></tt>.
148: *
149: * <p>
150: * This value is only used during creation and will not dynamically
151: * change the store directory when set after the create step has finished.
152: *
153: * @jmx:managed-attribute
154: *
155: * @param dirName A sub-directory name.
156: */
157: public void setStoreDirectoryName(final String dirName) {
158: this .storeDirName = dirName;
159: }
160:
161: /**
162: * Get the sub-directory name under the server data directory
163: * where entity data is stored.
164: *
165: * @jmx:managed-attibute
166: *
167: * @see #setStoreDirectoryName
168: *
169: * @return A sub-directory name.
170: */
171: public String getStoreDirectoryName() {
172: return storeDirName;
173: }
174:
175: /**
176: * Returns the directory used to store entity state files.
177: *
178: * @jmx:managed-attibute
179: *
180: * @return The directory used to store entity state files.
181: */
182: public File getStoreDirectory() {
183: return storeDir;
184: }
185:
186: protected void createService() throws Exception {
187: boolean debug = log.isDebugEnabled();
188:
189: // Initialize the dataStore
190:
191: String ejbName = con.getBeanMetaData().getEjbName();
192:
193: // Get the system data directory
194: File dir = ServerConfigLocator.locate().getServerDataDir();
195:
196: //
197: // jason: may have to use a generated token from container config
198: // to determine a unique name for this config for the given
199: // entity name. it must persist through restarts though...
200: //
201:
202: // Setup the reference to the entity data store directory
203: dir = new File(dir, storeDirName);
204: dir = new File(dir, ejbName);
205: storeDir = dir;
206:
207: if (debug) {
208: log.debug("Storing entity state for '" + ejbName + "' in: "
209: + storeDir);
210: }
211:
212: // if the directory does not exist then try to create it
213: if (!storeDir.exists()) {
214: if (!storeDir.mkdirs()) {
215: throw new IOException("Failed to create directory: "
216: + storeDir);
217: }
218: }
219:
220: // make sure we have a directory
221: if (!storeDir.isDirectory()) {
222: throw new IOException(
223: "File exists where directory expected: " + storeDir);
224: }
225:
226: // make sure we can read and write to it
227: if (!storeDir.canWrite() || !storeDir.canRead()) {
228: throw new IOException(
229: "Directory must be readable and writable: "
230: + storeDir);
231: }
232:
233: // Get the ID field
234: idField = con.getBeanClass().getField("id");
235: if (debug)
236: log.debug("Using id field: " + idField);
237:
238: // Lookup the isModified method if it exists
239: try {
240: isModified = con.getBeanClass().getMethod("isModified",
241: new Class[0]);
242: if (!isModified.getReturnType().equals(Boolean.TYPE)) {
243: isModified = null; // Has to have "boolean" as return type!
244: log
245: .warn("Found isModified method, but return type is not boolean; ignoring");
246: } else {
247: if (debug)
248: log.debug("Using isModified method: " + isModified);
249: }
250: } catch (NoSuchMethodException ignored) {
251: }
252: }
253:
254: /**
255: * Try to remove the store directory, if we can't then ignore.
256: */
257: protected void destroyService() throws Exception {
258: storeDir.delete();
259: }
260:
261: public Object createBeanClassInstance() throws Exception {
262: return con.getBeanClass().newInstance();
263: }
264:
265: /**
266: * Reset all attributes to default value
267: *
268: * <p>
269: * The EJB 1.1 specification is not entirely clear about this,
270: * the EJB 2.0 spec is, see page 169.
271: * Robustness is more important than raw speed for most server
272: * applications, and not resetting atrribute values result in
273: * *very* weird errors (old states re-appear in different instances and the
274: * developer thinks he's on drugs).
275: */
276: public void initEntity(final EntityEnterpriseContext ctx) {
277: // first get cmp metadata of this entity
278: Object instance = ctx.getInstance();
279: Class ejbClass = instance.getClass();
280: Field cmpField;
281: Class cmpFieldType;
282:
283: EntityMetaData metaData = (EntityMetaData) con
284: .getBeanMetaData();
285: Iterator i = metaData.getCMPFields();
286:
287: while (i.hasNext()) {
288: // get the field declaration
289: try {
290: cmpField = ejbClass.getField((String) i.next());
291: cmpFieldType = cmpField.getType();
292: // find the type of the field and reset it
293: // to the default value
294: if (cmpFieldType.equals(boolean.class)) {
295: cmpField.setBoolean(instance, false);
296: } else if (cmpFieldType.equals(byte.class)) {
297: cmpField.setByte(instance, (byte) 0);
298: } else if (cmpFieldType.equals(int.class)) {
299: cmpField.setInt(instance, 0);
300: } else if (cmpFieldType.equals(long.class)) {
301: cmpField.setLong(instance, 0L);
302: } else if (cmpFieldType.equals(short.class)) {
303: cmpField.setShort(instance, (short) 0);
304: } else if (cmpFieldType.equals(char.class)) {
305: cmpField.setChar(instance, '\u0000');
306: } else if (cmpFieldType.equals(double.class)) {
307: cmpField.setDouble(instance, 0d);
308: } else if (cmpFieldType.equals(float.class)) {
309: cmpField.setFloat(instance, 0f);
310: } else {
311: cmpField.set(instance, null);
312: }
313: } catch (NoSuchFieldException e) {
314: // will be here with dependant value object's private attributes
315: // should not be a problem
316: } catch (Exception e) {
317: throw new EJBException(e);
318: }
319: }
320: }
321:
322: public Object createEntity(final Method m, final Object[] args,
323: final EntityEnterpriseContext ctx) throws Exception {
324: try {
325: Object id = idField.get(ctx.getInstance());
326:
327: // Check exist
328: if (getFile(id).exists())
329: throw new DuplicateKeyException("Already exists: " + id);
330:
331: // Store to file
332: storeEntity(id, ctx.getInstance());
333:
334: return id;
335: } catch (IllegalAccessException e) {
336: throw new CreateException("Could not create entity: " + e);
337: }
338: }
339:
340: public Object postCreateEntity(final Method m, final Object[] args,
341: final EntityEnterpriseContext ctx) throws Exception {
342: return null;
343: }
344:
345: public Object findEntity(final Method finderMethod,
346: final Object[] args, final EntityEnterpriseContext ctx,
347: GenericEntityObjectFactory factory) throws FinderException {
348: if (finderMethod.getName().equals("findByPrimaryKey")) {
349: if (!getFile(args[0]).exists())
350: throw new FinderException(args[0] + " does not exist");
351:
352: return factory.getEntityEJBObject(args[0]);
353: }
354:
355: return null;
356: }
357:
358: public Collection findEntities(final Method finderMethod,
359: final Object[] args, final EntityEnterpriseContext ctx,
360: GenericEntityObjectFactory factory) {
361: if (finderMethod.getName().equals("findAll")) {
362: String[] files = storeDir.list(new FilenameSuffixFilter(
363: ".ser"));
364: ArrayList result = new ArrayList(files.length);
365: for (int i = 0; i < files.length; i++) {
366: final String key = files[i].substring(0, files[i]
367: .length() - 4);
368: result.add(factory.getEntityEJBObject(key));
369: }
370:
371: return result;
372: } else {
373: // we only support find all
374: return Collections.EMPTY_LIST;
375: }
376: }
377:
378: /**
379: * Non-operation.
380: */
381: public void activateEntity(final EntityEnterpriseContext ctx) {
382: // Nothing to do
383: }
384:
385: public void loadEntity(final EntityEnterpriseContext ctx) {
386: try {
387: Object obj = ctx.getInstance();
388:
389: // Read fields
390: ObjectInputStream in = new CMPObjectInputStream(
391: new BufferedInputStream(new FileInputStream(
392: getFile(ctx.getId()))));
393:
394: try {
395: Field[] f = obj.getClass().getFields();
396: for (int i = 0; i < f.length; i++) {
397: f[i].set(obj, in.readObject());
398: }
399: } finally {
400: in.close();
401: }
402: } catch (Exception e) {
403: throw new EJBException("Load failed", e);
404: }
405: }
406:
407: private void storeEntity(Object id, Object obj) {
408: try {
409: // Store fields
410: ObjectOutputStream out = new CMPObjectOutputStream(
411: new BufferedOutputStream(new FileOutputStream(
412: getFile(id))));
413:
414: try {
415: Field[] f = obj.getClass().getFields();
416: for (int i = 0; i < f.length; i++) {
417: out.writeObject(f[i].get(obj));
418: }
419: } finally {
420: out.close();
421: }
422: } catch (Exception e) {
423: throw new EJBException("Store failed", e);
424: }
425: }
426:
427: public boolean isStoreRequired(final EntityEnterpriseContext ctx)
428: throws Exception {
429: if (isModified == null) {
430: return true;
431: }
432:
433: Boolean modified = (Boolean) isModified.invoke(ctx
434: .getInstance(), new Object[0]);
435: return modified.booleanValue();
436: }
437:
438: public boolean isModified(EntityEnterpriseContext ctx)
439: throws Exception {
440: return isStoreRequired(ctx);
441: }
442:
443: public void storeEntity(final EntityEnterpriseContext ctx) {
444: storeEntity(ctx.getId(), ctx.getInstance());
445: }
446:
447: /**
448: * Non-operation.
449: */
450: public void passivateEntity(final EntityEnterpriseContext ctx) {
451: // This plugin doesn't do anything specific
452: }
453:
454: public void removeEntity(final EntityEnterpriseContext ctx)
455: throws RemoveException {
456: // Remove file
457: File file = getFile(ctx.getId());
458:
459: if (!file.delete()) {
460: throw new RemoveException("Could not remove file: " + file);
461: }
462: }
463:
464: protected File getFile(final Object id) {
465: return new File(storeDir, String.valueOf(id) + ".ser");
466: }
467:
468: // Inner classes -------------------------------------------------
469:
470: static class CMPObjectOutputStream extends ObjectOutputStream {
471: public CMPObjectOutputStream(final OutputStream out)
472: throws IOException {
473: super (out);
474: enableReplaceObject(true);
475: }
476:
477: protected Object replaceObject(final Object obj)
478: throws IOException {
479: if (obj instanceof EJBObject)
480: return ((EJBObject) obj).getHandle();
481:
482: return obj;
483: }
484: }
485:
486: static class CMPObjectInputStream extends ObjectInputStream {
487: public CMPObjectInputStream(final InputStream in)
488: throws IOException {
489: super (in);
490: enableResolveObject(true);
491: }
492:
493: protected Object resolveObject(final Object obj)
494: throws IOException {
495: if (obj instanceof Handle)
496: return ((Handle) obj).getEJBObject();
497:
498: return obj;
499: }
500: }
501: }
|