I think after you changed the Configuration interface some classes won't compile any more because they also implement this interface. Did you check that?
I like the idea with reloading properties, but the actual implementation seems to be a bit too specific for my taste. It is now possible to reload properties read from file. Some weeks ago the configuration classes have been extended to support loading from a URL. Here a reload can't be performed at the moment. And Tim's suggestion to specify a refresh delay in the configuration definition XML file is not supported either.
I admit that reloading file based properties will be needed most times, so this is a good beginning. But maybe we can find a more generic approach that also supports the other use cases?
Perhaps we can introduce something like a Trigger interface (or a similar concept). Such a trigger can be passed to the Reload decorator. Then the decorator won't be limited to file change events. Just an idea...
Regards Oli
Emmanuel Bourg schrieb:
He is an implementation of the reloadable decorator suggested by Eric. I have also added a set/getRefreshDelay method.
Emmanuel Bourg
Eric Galluzzo wrote:
Alternatively, it might be nice to introduce a FileConfiguration interface that just has a java.io.File getFile() method. Both DOM4JConfiguration and PropertiesConfiguration would implement this. Then one could repackage your existing ReloadablePropertiesConfiguration as a ReloadableConfiguration that implements Configuration but delegates to another FileConfiguration and checks the file every so often. Thus:
Configuration config = new ReloadableConfiguration( new DOM4JConfiguration( myXMLFile ) );
or
Configuration config = new ReloadableConfiguration( new PropertiesConfiguration( myPropFile ) );
This is a Decorator design reminiscent of FilteredOutputStream and FilteredInputStream.
- Eric
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------------------------------------------------------------------------
Index: src/java/org/apache/commons/configuration/BaseConfiguration.java
===================================================================
RCS file: /home/cvspublic/jakarta-commons-sandbox/configuration/src/java/org/apache/commons/configuration/BaseConfiguration.java,v
retrieving revision 1.16
diff -u -r1.16 BaseConfiguration.java
--- src/java/org/apache/commons/configuration/BaseConfiguration.java 17 Oct 2003 08:11:52 -0000 1.16
+++ src/java/org/apache/commons/configuration/BaseConfiguration.java 16 Dec 2003 14:33:18 -0000
@@ -55,6 +55,7 @@
*/
import java.util.Iterator;
+import java.util.Map;
import org.apache.commons.collections.SequencedHashMap;
@@ -86,7 +87,7 @@
public class BaseConfiguration extends AbstractConfiguration
{
/** stores the configuration key-value pairs */
- private SequencedHashMap store = new SequencedHashMap();
+ private Map store = new SequencedHashMap();
/**
* Empty constructor. You must add all the values to this configuration.
@@ -200,6 +201,10 @@
}
}
+ public void clear() {
+ store.clear();
+ }
+
/**
* Get the list of the keys contained in the configuration
* repository.
@@ -208,6 +213,6 @@
*/
public Iterator getKeys()
{
- return store.iterator();
+ return store.keySet().iterator();
}
}
Index: src/java/org/apache/commons/configuration/Configuration.java
===================================================================
RCS file: /home/cvspublic/jakarta-commons-sandbox/configuration/src/java/org/apache/commons/configuration/Configuration.java,v
retrieving revision 1.6
diff -u -r1.6 Configuration.java
--- src/java/org/apache/commons/configuration/Configuration.java 12 Nov 2003 08:12:33 -0000 1.6
+++ src/java/org/apache/commons/configuration/Configuration.java 16 Dec 2003 14:33:18 -0000
@@ -131,6 +131,11 @@
void clearProperty(String key);
/**
+ * Clear all properties in the configuration.
+ */
+ void clear();
+
+ /**
* Gets a property from the configuration.
*
* @param key property to retrieve
Index: src/java/org/apache/commons/configuration/DOM4JConfiguration.java
===================================================================
RCS file: /home/cvspublic/jakarta-commons-sandbox/configuration/src/java/org/apache/commons/configuration/DOM4JConfiguration.java,v
retrieving revision 1.7
diff -u -r1.7 DOM4JConfiguration.java
--- src/java/org/apache/commons/configuration/DOM4JConfiguration.java 11 Nov 2003 15:02:07 -0000 1.7
+++ src/java/org/apache/commons/configuration/DOM4JConfiguration.java 16 Dec 2003 14:33:20 -0000
@@ -87,7 +87,7 @@
* @author <a href="mailto:[EMAIL PROTECTED]">Daniel Rall</a>
* @since 0.8.1
*/
-public class DOM4JConfiguration extends XMLConfiguration
+public class DOM4JConfiguration extends XMLConfiguration implements FileConfiguration
{
// For conformance with xpath
private static final char ATTRIB_MARKER = '@';
Index: src/java/org/apache/commons/configuration/PropertiesConfiguration.java
===================================================================
RCS file: /home/cvspublic/jakarta-commons-sandbox/configuration/src/java/org/apache/commons/configuration/PropertiesConfiguration.java,v
retrieving revision 1.12
diff -u -r1.12 PropertiesConfiguration.java
--- src/java/org/apache/commons/configuration/PropertiesConfiguration.java 11 Nov 2003 15:02:07 -0000 1.12
+++ src/java/org/apache/commons/configuration/PropertiesConfiguration.java 16 Dec 2003 14:33:20 -0000
@@ -95,7 +95,7 @@
*/
public class PropertiesConfiguration
extends BasePropertiesConfiguration
- implements Configuration
+ implements FileConfiguration
{
/** Static logger */
Log log = LogFactory.getLog(PropertiesConfiguration.class);
@@ -166,6 +166,16 @@
public void load(String fileName) throws IOException
{
load(getPropertyStream(fileName));
+ }
+
+ /**
+ * Save the properties to the fileName set by setFileName
+ *
+ * @throws IOException
+ */
+ public void save() throws IOException
+ {
+ save(getFileName());
}
/**
------------------------------------------------------------------------
package org.apache.commons.configuration;
/* ==================================================================== * The Apache Software License, Version 1.1 * * Copyright (c) 1999-2003 The Apache Software Foundation. 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. * * 3. The end-user documentation included with the redistribution, if * any, must include the following acknowledgement: * "This product includes software developed by the * Apache Software Foundation (http://www.apache.org/)." * Alternately, this acknowledgement may appear in the software itself, * if and wherever such third-party acknowledgements normally appear. * * 4. The names "The Jakarta Project", "Commons", and "Apache Software * Foundation" must not be used to endorse or promote products derived * from this software without prior written permission. For written * permission, please contact [EMAIL PROTECTED] * * 5. Products derived from this software may not be called "Apache" * nor may "Apache" appear in their names without prior written * permission of the Apache Software Foundation. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 APACHE SOFTWARE FOUNDATION OR * ITS 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 INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. */
import java.io.IOException;
/** * A file based configuration. * * @author Emmanuel Bourg * @author Eric Galluzo * @version $Revision$, $Date$ */ public interface FileConfiguration extends Configuration {
/** * Save the properties to the fileName set by setFileName. * * @throws IOException */ void save() throws IOException;
/**
* Load the properties from the fileName set by setFileName
*
* @throws IOException
*/ void load() throws Exception;
/** * Return the name of the file. */ String getFileName();
}
------------------------------------------------------------------------
package org.apache.commons.configuration;
/* ==================================================================== * The Apache Software License, Version 1.1 * * Copyright (c) 1999-2003 The Apache Software Foundation. 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. * * 3. The end-user documentation included with the redistribution, if * any, must include the following acknowledgement: * "This product includes software developed by the * Apache Software Foundation (http://www.apache.org/)." * Alternately, this acknowledgement may appear in the software itself, * if and wherever such third-party acknowledgements normally appear. * * 4. The names "The Jakarta Project", "Commons", and "Apache Software * Foundation" must not be used to endorse or promote products derived * from this software without prior written permission. For written * permission, please contact [EMAIL PROTECTED] * * 5. Products derived from this software may not be called "Apache" * nor may "Apache" appear in their names without prior written * permission of the Apache Software Foundation. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 APACHE SOFTWARE FOUNDATION OR * ITS 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 INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. */
import java.io.IOException; import java.io.File; import java.util.Iterator; import java.util.Properties; import java.util.Vector;
import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory;
/** * A decorator around a [EMAIL PROTECTED] FileConfiguration} that will reload the * properties everytime the configuration file is changed. The file is checked * every time a property is accessed. The file is not reloaded more than once * every 5 seconds by default, this time can be changed by setting the refresh * delay. The automatic reloading can be disabled by calling * <code>setAutoReload(false)</code>, it's enabled by default. When the file * is reloaded the configuration is cleared * * @author Emmanuel Bourg * @author Eric Galluzo * @version $Revision$, $Date$ */ public class ReloadableConfiguration implements Configuration {
/** Logger */ private Log log = LogFactory.getLog(this.getClass());
private FileConfiguration configuration;
/** Should the configuration be reloaded on file changes ? */ protected boolean autoReload = true;
/** The last time the configuration file was modified. */ protected long lastModified;
/** The last time the file was checked for changes. */ protected long lastChecked;
/** The minimum delay in milliseconds between checks. */ protected long refreshDelay = 5000;
/** The lock to block read access while reloading */ private Object reloadLock = new Object();
/** * Creates a reloadable configuration. * * @param configuration */ public ReloadableConfiguration(FileConfiguration configuration) { this.configuration = configuration;
File file = new File(configuration.getFileName()); lastModified = file.lastModified(); }
/** * Tell if the auto reload mode is enabled or disabled. */ public boolean isAutoReload() { return autoReload; }
/** * Enable or disable the automatic reloading of the configuration * when the file is changed. */ public void setAutoReload(boolean autoReload) { this.autoReload = autoReload; }
public long getRefreshDelay() { return refreshDelay; }
/** * Set the minimal time between two reloadings. * * @param refreshDelay refresh delay in milliseconds */ public void setRefreshDelay(long refreshDelay) { this.refreshDelay = refreshDelay; }
/** * Check if the configuration has changed since the last * time it was loaded. */ protected boolean hasChanged() { if (configuration.getFileName() == null) { return false; }
File file = new File(configuration.getFileName()); return (file.lastModified() > lastModified); }
/** * Reload the configuration if the file has been modified. The * configuration will not be reloaded more than once every 5 seconds. */ protected void reload() { long now = System.currentTimeMillis(); if (autoReload) { synchronized (reloadLock) { if ((now > lastChecked + refreshDelay) && hasChanged()) {
lastChecked = now;
log.debug("Reloading configuration " + configuration.getFileName());
try { configuration.clear(); configuration.load(); } catch (Exception e) { log.warn("Unable to reload configuration", e); } } } } }
public void save(String filename) throws IOException { configuration.save(); lastModified = System.currentTimeMillis(); }
public Properties getProperties(String key) { reload(); return configuration.getProperties(key); }
public Object getProperty(String key) { reload(); return configuration.getProperty(key); }
public boolean getBoolean(String key) { reload(); return configuration.getBoolean(key); }
public boolean getBoolean(String key, boolean defaultValue) { reload(); return configuration.getBoolean(key, defaultValue); }
public Boolean getBoolean(String key, Boolean defaultValue) { reload(); return configuration.getBoolean(key, defaultValue); }
public byte getByte(String key) { reload(); return configuration.getByte(key); }
public byte getByte(String key, byte defaultValue) { reload(); return configuration.getByte(key, defaultValue); }
public Byte getByte(String key, Byte defaultValue) { reload(); return configuration.getByte(key, defaultValue); }
public double getDouble(String key) { reload(); return configuration.getDouble(key); }
public double getDouble(String key, double defaultValue) { reload(); return configuration.getDouble(key, defaultValue); }
public Double getDouble(String key, Double defaultValue) { reload(); return configuration.getDouble(key, defaultValue); }
public float getFloat(String key) { reload(); return configuration.getFloat(key); }
public float getFloat(String key, float defaultValue) { reload(); return configuration.getFloat(key, defaultValue); }
public Float getFloat(String key, Float defaultValue) { reload(); return configuration.getFloat(key, defaultValue); }
public int getInt(String key) { reload(); return configuration.getInt(key); }
public int getInt(String key, int defaultValue) { reload(); return configuration.getInt(key, defaultValue); }
public Integer getInteger(String key, Integer defaultValue) { reload(); return configuration.getInteger(key, defaultValue); }
public long getLong(String key) { reload(); return configuration.getLong(key); }
public long getLong(String key, long defaultValue) { reload(); return configuration.getLong(key, defaultValue); }
public Long getLong(String key, Long defaultValue) { reload(); return configuration.getLong(key, defaultValue); }
public short getShort(String key) { reload(); return configuration.getShort(key); }
public short getShort(String key, short defaultValue) { reload(); return configuration.getShort(key, defaultValue); }
public Short getShort(String key, Short defaultValue) { reload(); return configuration.getShort(key, defaultValue); }
public String getString(String key) { reload(); return configuration.getString(key); }
public String getString(String key, String defaultValue) { reload(); return configuration.getString(key, defaultValue); }
public String[] getStringArray(String key) { reload(); return configuration.getStringArray(key); }
public Vector getVector(String key) { reload(); return configuration.getVector(key); }
public Vector getVector(String key, Vector defaultValue) { reload(); return configuration.getVector(key, defaultValue); }
public Configuration subset(String prefix) { reload(); return configuration.subset(prefix); }
public Iterator getKeys() { reload(); return configuration.getKeys(); }
public Iterator getKeys(String prefix) { reload(); return configuration.getKeys(prefix); }
public boolean isEmpty() { return configuration.isEmpty(); }
public boolean containsKey(String key) { return configuration.containsKey(key); }
public void addProperty(String key, Object value) { configuration.addProperty(key, value); }
public void setProperty(String key, Object value) { configuration.setProperty(key, value); }
public void clearProperty(String key) { configuration.clearProperty(key); }
public void clear() { configuration.clear(); }
}
------------------------------------------------------------------------
package org.apache.commons.configuration;
/* ==================================================================== * The Apache Software License, Version 1.1 * * Copyright (c) 1999-2003 The Apache Software Foundation. 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. * * 3. The end-user documentation included with the redistribution, if * any, must include the following acknowledgement: * "This product includes software developed by the * Apache Software Foundation (http://www.apache.org/)." * Alternately, this acknowledgement may appear in the software itself, * if and wherever such third-party acknowledgements normally appear. * * 4. The names "The Jakarta Project", "Commons", and "Apache Software * Foundation" must not be used to endorse or promote products derived * from this software without prior written permission. For written * permission, please contact [EMAIL PROTECTED] * * 5. Products derived from this software may not be called "Apache" * nor may "Apache" appear in their names without prior written * permission of the Apache Software Foundation. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 APACHE SOFTWARE FOUNDATION OR * ITS 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 INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * <http://www.apache.org/>. */
import java.io.File; import java.io.FileWriter;
import junit.framework.TestCase;
/** * Test case for the ReloadableConfiguration class. * * @author Emmanuel Bourg * @version $Revision$, $Date$ */ public class TestReloadableConfiguration extends TestCase {
public void testAutomaticReloading() throws Exception {
// create a new configuration File file = new File("testReload.properties");
try { FileWriter out = new FileWriter(file); out.write("string=value1"); out.flush(); out.close();
// load the configuration PropertiesConfiguration pc = new PropertiesConfiguration("testReload.properties"); pc.setFileName("testReload.properties");
ReloadableConfiguration rc = new ReloadableConfiguration(pc); rc.setAutoReload(false); assertEquals("Initial value", "value1", rc.getString("string"));
Thread.sleep(500);
// change the file out = new FileWriter(file); out.write("string=value2"); out.flush(); out.close();
// test the automatic reloading assertEquals("Modified value with disabled reloading", "value1", rc.getString("string")); rc.setAutoReload(true); assertEquals("Modified value with enabled reloading", "value2", rc.getString("string")); } finally { // delete the test file file.delete(); } }
}
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