The ModifiedSelector.java source code
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.tools.ant.types.selectors.modifiedselector;
// Java
import java.util.Comparator;
import java.util.Vector;
import java.util.Iterator;
import java.io.File;
// Ant
import org.apache.tools.ant.Project;
import org.apache.tools.ant.IntrospectionHelper;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.BuildListener;
import org.apache.tools.ant.BuildEvent;
import org.apache.tools.ant.types.EnumeratedAttribute;
import org.apache.tools.ant.types.Parameter;
import org.apache.tools.ant.types.Path;
import org.apache.tools.ant.types.Resource;
import org.apache.tools.ant.types.resources.FileResource;
import org.apache.tools.ant.types.resources.selectors.ResourceSelector;
import org.apache.tools.ant.types.selectors.BaseExtendSelector;
import org.apache.tools.ant.util.FileUtils;
import org.apache.tools.ant.util.ResourceUtils;
/**
* <p>Selector class that uses Algorithm, Cache and Comparator
* for its work.
* The <i>Algorithm is used for computing a hashvalue for a file.
* The <i>Comparator decides whether to select or not.
* The <i>Cache stores the other value for comparison by the Comparator
* in a persistent manner.</p>
*
* <p>The ModifiedSelector is implemented as a CoreSelector and uses default
* values for all its attributes therefore the simpliest example is <pre>
* <copy todir="dest">
* <filelist dir="src">
* <modified/>
* </filelist>
* </copy>
* </pre>
*
* <p>The same example rewritten as CoreSelector with setting the all values
* (same as defaults are) would be <pre>
* <copy todir="dest">
* <filelist dir="src">
* <modified update="true"
* cache="propertyfile"
* algorithm="digest"
* comparator="equal">
* <param name="cache.cachefile" value="cache.properties"/>
* <param name="algorithm.algorithm" value="MD5"/>
* </modified>
* </filelist>
* </copy>
* </pre>
*
* <p>And the same rewritten as CustomSelector would be * <copy todir="dest">
* <filelist dir="src">
* <custom class="org.apache.tools.ant.type.selectors.ModifiedSelector">
* <param name="update" value="true"/>
* <param name="cache" value="propertyfile"/>
* <param name="algorithm" value="digest"/>
* <param name="comparator" value="equal"/>
* <param name="cache.cachefile" value="cache.properties"/>
* <param name="algorithm.algorithm" value="MD5"/>
* </custom>
* </filelist>
* </copy>
* </pre>
*
* <p>If you want to provide your own interface implementation you can do
* that via the *classname attributes. If the classes are not on Ant's core
* classpath, you will have to provide the path via nested <classpath>
* element, so that the selector can find the classes. <pre>
* <modified cacheclassname="com.mycompany.MyCache">
* <classpath>
* <pathelement location="lib/mycompony-antutil.jar"/>
* </classpath>
* </modified>
* </pre>
*
* <p>All these three examples copy the files from src to dest
* using the ModifiedSelector. The ModifiedSelector uses the <i>PropertyfileCache
* </i>, the DigestAlgorithm and the EqualComparator for its
* work. The PropertyfileCache stores key-value-pairs in a simple java
* properties file. The filename is <i>cache.properties. The update
* flag lets the selector update the values in the cache (and on first call
* creates the cache). The <i>DigestAlgorithm computes a hashvalue using the
* java.security.MessageDigest class with its MD5-Algorithm and its standard
* provider. The new computed hashvalue and the stored one are compared by
* the <i>EqualComparator which returns 'true' (more correct a value not
* equals zero (1)) if the values are not the same using simple String
* comparison.</p>
*
* <p>A useful scenario for this selector is inside a build environment
* for homepage generation (e.g. with <a href="http://forrest.apache.org/">
* Apache Forrest</a>). * <target name="generate-and-upload-site">
* <echo> generate the site using forrest </echo>
* <antcall target="site"/>
*
* <echo> upload the changed files </echo>
* <ftp server="${ftp.server}" userid="${ftp.user}" password="${ftp.pwd}">
* <fileset dir="htdocs/manual">
* <modified/>
* </fileset>
* </ftp>
* </target>
* </pre> Here all changed files are uploaded to the server. The
* ModifiedSelector saves therefore much upload time.</p>
*
*
* <p>This selector uses reflection for setting the values of its three interfaces
* (using org.apache.tools.ant.IntrospectionHelper) therefore no special
* 'configuration interfaces' has to be implemented by new caches, algorithms or
* comparators. All present <i>setXX methods can be used. E.g. the DigestAlgorithm
* can use a specified provider for computing its value. For selecting this
* there is a <i>setProvider(String providername) method. So you can use
* a nested <i><param name="algorithm.provider" value="MyProvider"/>.
*
*
* @since Ant 1.6
*/
public class ModifiedSelector extends BaseExtendSelector
implements BuildListener, ResourceSelector {
// ----- attributes -----
/** Cache name for later instantiation. */
private CacheName cacheName = null;
/** User specified classname for Cache. */
private String cacheClass;
/** Algorithm name for later instantiation. */
private AlgorithmName algoName = null;
/** User specified classname for Algorithm. */
private String algorithmClass;
/** Comparator name for later instantiation. */
private ComparatorName compName = null;
/** User specified classname for Comparator. */
private String comparatorClass;
/** Should the cache be updated? */
private boolean update = true;
/** Are directories selected? */
private boolean selectDirectories = true;
/**
* Should Resources whithout an InputStream, and
* therefore without checking, be selected?
*/
private boolean selectResourcesWithoutInputStream = true;
/** Delay the writing of the cache file */
private boolean delayUpdate = true;
// ----- internal member variables -----
/** How should the cached value and the new one compared? */
private Comparator comparator = null;
/** Algorithm for computing new values and updating the cache. */
private Algorithm algorithm = null;
/** The Cache containing the old values. */
private Cache cache = null;
/** Count of modified properties */
private int modified = 0;
/** Flag whether this object is configured. Configuration is only done once. */
private boolean isConfigured = false;
/**
* Parameter vector with parameters for later initialization.
* @see #configure
*/
private Vector configParameter = new Vector();
/**
* Parameter vector with special parameters for later initialization.
* The names have the pattern '*.*', e.g. 'cache.cachefile'.
* These parameters are used <b>after the parameters with the pattern '*'.
* @see #configure
*/
private Vector specialParameter = new Vector();
/** The classloader of this class. */
private ClassLoader myClassLoader = null;
/** provided classpath for the classloader */
private Path classpath = null;
// ----- constructors -----
/** Bean-Constructor. */
public ModifiedSelector() {
}
// ----- configuration -----
/** Overrides BaseSelector.verifySettings(). */
public void verifySettings() {
configure();
if (cache == null) {
setError("Cache must be set.");
} else if (algorithm == null) {
setError("Algorithm must be set.");
} else if (!cache.isValid()) {
setError("Cache must be proper configured.");
} else if (!algorithm.isValid()) {
setError("Algorithm must be proper configured.");
}
}
/**
* Configures this Selector.
* Does this work only once per Selector object.
* <p>Because some problems while configuring from Selector
* the configuration is done in the following order:<ol>
* <li> collect the configuration data
* <li> wait for the first isSelected() call
* <li> set the default values
* <li> set values for name pattern '*': update, cache, algorithm, comparator
* <li> set values for name pattern '*.*: cache.cachefile, ...
* </ol>
* <p>This configuration algorithm is needed because you don't know
* the order of arriving config-data. E.g. if you first set the
* <i>cache.cachefilename and after that the cache itself,
* the default value for cachefilename is used, because setting the
* cache implies creating a new Cache instance - with its defaults.</p>
*/
public void configure() {
//
// ----- The "Singleton" -----
//
if (isConfigured) {
return;
}
isConfigured = true;
//
// ----- Set default values -----
//
Project p = getProject();
String filename = "cache.properties";
File cachefile = null;
if (p != null) {
// normal use inside Ant
cachefile = new File(p.getBaseDir(), filename);
// set self as a BuildListener to delay cachefile saves
getProject().addBuildListener(this);
} else {
// no reference to project - e.g. during normal JUnit tests
cachefile = new File(filename);
setDelayUpdate(false);
}
Cache defaultCache = new PropertiesfileCache(cachefile);
Algorithm defaultAlgorithm = new DigestAlgorithm();
Comparator defaultComparator = new EqualComparator();
update = true;
selectDirectories = true;
//
// ----- Set the main attributes, pattern '*' -----
//
for (Iterator itConfig = configParameter.iterator(); itConfig.hasNext();) {
Parameter par = (Parameter) itConfig.next();
if (par.getName().indexOf(".") > 0) {
// this is a *.* parameter for later use
specialParameter.add(par);
} else {
useParameter(par);
}
}
configParameter = new Vector();
// specify the algorithm classname
if (algoName != null) {
// use Algorithm defined via name
if ("hashvalue".equals(algoName.getValue())) {
algorithm = new HashvalueAlgorithm();
} else if ("digest".equals(algoName.getValue())) {
algorithm = new DigestAlgorithm();
} else if ("checksum".equals(algoName.getValue())) {
algorithm = new ChecksumAlgorithm();
}
} else {
if (algorithmClass != null) {
// use Algorithm specified by classname
algorithm = (Algorithm) loadClass(
algorithmClass,
"is not an Algorithm.",
Algorithm.class);
} else {
// nothing specified - use default
algorithm = defaultAlgorithm;
}
}
// specify the cache classname
if (cacheName != null) {
// use Cache defined via name
if ("propertyfile".equals(cacheName.getValue())) {
cache = new PropertiesfileCache();
}
} else {
if (cacheClass != null) {
// use Cache specified by classname
cache = (Cache) loadClass(cacheClass, "is not a Cache.", Cache.class);
} else {
// nothing specified - use default
cache = defaultCache;
}
}
// specify the comparator classname
if (compName != null) {
// use Algorithm defined via name
if ("equal".equals(compName.getValue())) {
comparator = new EqualComparator();
} else if ("rule".equals(compName.getValue())) {
// TODO there is a problem with the constructor for the RBC.
// you have to provide the rules in the constructors - no setters
// available.
throw new BuildException("RuleBasedCollator not yet supported.");
// Have to think about lazy initialization here... JHM
// comparator = new java.text.RuleBasedCollator();
}
} else {
if (comparatorClass != null) {
// use Algorithm specified by classname
comparator = (Comparator) loadClass(
comparatorClass,
"is not a Comparator.",
Comparator.class);
} else {
// nothing specified - use default
comparator = defaultComparator;
}
}
//
// ----- Set the special attributes, pattern '*.*' -----
//
for (Iterator itSpecial = specialParameter.iterator(); itSpecial.hasNext();) {
Parameter par = (Parameter) itSpecial.next();
useParameter(par);
}
specialParameter = new Vector();
}
/**
* Loads the specified class and initializes an object of that class.
* Throws a BuildException using the given message if an error occurs during
* loading/instantiation or if the object is not from the given type.
* @param classname the classname
* @param msg the message-part for the BuildException
* @param type the type to check against
* @return a castable object
*/
protected Object loadClass(String classname, String msg, Class type) {
try {
// load the specified class
ClassLoader cl = getClassLoader();
Class clazz = null;
if (cl != null) {
clazz = cl.loadClass(classname);
} else {
clazz = Class.forName(classname);
}
Object rv = clazz.newInstance();
if (!type.isInstance(rv)) {
throw new BuildException("Specified class (" + classname + ") " + msg);
}
return rv;
} catch (ClassNotFoundException e) {
throw new BuildException("Specified class (" + classname + ") not found.");
} catch (Exception e) {
throw new BuildException(e);
}
}
// ----- the selection work -----
/**
* Implementation of ResourceSelector.isSelected().
*
* @param resource The resource to check
* @return whether the resource is selected
* @see ResourceSelector#isSelected(Resource)
*/
public boolean isSelected(Resource resource) {
if (resource.isFilesystemOnly()) {
// We have a 'resourced' file, so reconvert it and use
// the 'old' implementation.
FileResource fileResource = (FileResource) resource;
File file = fileResource.getFile();
String filename = fileResource.getName();
File basedir = fileResource.getBaseDir();
return isSelected(basedir, filename, file);
} else {
try {
// How to handle non-file-Resources? I copy temporarily the
// resource to a file and use the file-implementation.
FileUtils fu = FileUtils.getFileUtils();
File tmpFile = fu.createTempFile("modified-", ".tmp", null);
Resource tmpResource = new FileResource(tmpFile);
ResourceUtils.copyResource(resource, tmpResource);
boolean isSelected = isSelected(tmpFile.getParentFile(),
tmpFile.getName(),
resource.toLongString());
tmpFile.delete();
return isSelected;
} catch (UnsupportedOperationException uoe) {
log("The resource '"
+ resource.getName()
+ "' does not provide an InputStream, so it is not checked. "
+ "Akkording to 'selres' attribute value it is "
+ ((selectResourcesWithoutInputStream) ? "" : " not")
+ "selected.", Project.MSG_INFO);
return selectResourcesWithoutInputStream;
} catch (Exception e) {
throw new BuildException(e);
}
}
}
/**
* Implementation of BaseExtendSelector.isSelected().
*
* @param basedir as described in BaseExtendSelector
* @param filename as described in BaseExtendSelector
* @param file as described in BaseExtendSelector
* @return as described in BaseExtendSelector
*/
public boolean isSelected(File basedir, String filename, File file) {
return isSelected(basedir, filename, file.getAbsolutePath());
}
/**
* The business logic of this selector for use as ResourceSelector of
* FileSelector.
*
* @param basedir as described in BaseExtendSelector
* @param filename as described in BaseExtendSelector
* @param cacheKey the name for the key for storing the hashvalue
* @return
*/
private boolean isSelected(File basedir, String filename, String cacheKey) {
validate();
File f = new File(basedir, filename);
// You can not compute a value for a directory
if (f.isDirectory()) {
return selectDirectories;
}
// Get the values and do the comparison
String cachedValue = String.valueOf(cache.get(f.getAbsolutePath()));
String newValue = algorithm.getValue(f);
boolean rv = (comparator.compare(cachedValue, newValue) != 0);
// Maybe update the cache
if (update && rv) {
cache.put(f.getAbsolutePath(), newValue);
setModified(getModified() + 1);
if (!getDelayUpdate()) {
saveCache();
}
}
return rv;
}
/**
* save the cache file
*/
protected void saveCache() {
if (getModified() > 1) {
cache.save();
setModified(0);
}
}
// ----- attribute and nested element support -----
/**
* Setter for algorithmClass.
* @param classname new value
*/
public void setAlgorithmClass(String classname) {
algorithmClass = classname;
}
/**
* Setter for comparatorClass.
* @param classname new value
*/
public void setComparatorClass(String classname) {
comparatorClass = classname;
}
/**
* Setter for cacheClass.
* @param classname new value
*/
public void setCacheClass(String classname) {
cacheClass = classname;
}
/**
* Support for <i>update attribute.
* @param update new value
*/
public void setUpdate(boolean update) {
this.update = update;
}
/**
* Support for <i>seldirs attribute.
* @param seldirs new value
*/
public void setSeldirs(boolean seldirs) {
selectDirectories = seldirs;
}
/**
* Support for <i>selres attribute.
* @param newValue the new value
*/
public void setSelres(boolean newValue) {
this.selectResourcesWithoutInputStream = newValue;
}
/**
* Getter for the modified count
* @return modified count
*/
public int getModified() {
return modified;
}
/**
* Setter for the modified count
* @param modified count
*/
public void setModified(int modified) {
this.modified = modified;
}
/**
* Getter for the delay update
* @return true if we should delay for performance
*/
public boolean getDelayUpdate() {
return delayUpdate;
}
/**
* Setter for the delay update
* @param delayUpdate true if we should delay for performance
*/
public void setDelayUpdate(boolean delayUpdate) {
this.delayUpdate = delayUpdate;
}
/**
* Add the classpath.
* @param path the classpath
*/
public void addClasspath(Path path) {
if (classpath != null) {
throw new BuildException("<classpath> can be set only once.");
}
classpath = path;
}
/**
* Returns and initializes the classloader for this class.
* @return the classloader
*/
public ClassLoader getClassLoader() {
if (myClassLoader == null) {
myClassLoader = (classpath == null)
// the usual classloader
? getClass().getClassLoader()
// additional use the provided classpath
: getProject().createClassLoader(classpath);
}
return myClassLoader;
}
/**
* Set the used ClassLoader.
* If you invoke this selector by API (e.g. inside some testcases) the selector
* will use a different classloader for loading the interface implementations than
* the caller. Therefore you will get a ClassCastException if you get the
* implementations from the selector and cast them.
* @param loader the ClassLoader to use
*/
public void setClassLoader(ClassLoader loader) {
myClassLoader = loader;
}
/**
* Support for nested <param> tags.
* @param key the key of the parameter
* @param value the value of the parameter
*/
public void addParam(String key, Object value) {
Parameter par = new Parameter();
par.setName(key);
par.setValue(String.valueOf(value));
configParameter.add(par);
}
/**
* Support for nested <param> tags.
* @param parameter the parameter object
*/
public void addParam(Parameter parameter) {
configParameter.add(parameter);
}
/**
* Defined in org.apache.tools.ant.types.Parameterizable.
* Overwrite implementation in superclass because only special
* parameters are valid.
* @see #addParam(String,Object).
* @param parameters the parameters to set.
*/
public void setParameters(Parameter[] parameters) {
if (parameters != null) {
for (int i = 0; i < parameters.length; i++) {
configParameter.add(parameters[i]);
}
}
}
/**
* Support for nested <param name="" value=""/> tags.
* Parameter named <i>cache, algorithm,
* <i>comparator or update are mapped to
* the respective set-Method.
* Parameter which names starts with <i>cache. or
* <i>algorithm. or comparator. are tried
* to set on the appropriate object via its set-methods.
* Other parameters are invalid and an BuildException will
* be thrown.
*
* @param parameter Key and value as parameter object
*/
public void useParameter(Parameter parameter) {
String key = parameter.getName();
String value = parameter.getValue();
if ("cache".equals(key)) {
CacheName cn = new CacheName();
cn.setValue(value);
setCache(cn);
} else if ("algorithm".equals(key)) {
AlgorithmName an = new AlgorithmName();
an.setValue(value);
setAlgorithm(an);
} else if ("comparator".equals(key)) {
ComparatorName cn = new ComparatorName();
cn.setValue(value);
setComparator(cn);
} else if ("update".equals(key)) {
boolean updateValue =
("true".equalsIgnoreCase(value))
? true
: false;
setUpdate(updateValue);
} else if ("delayupdate".equals(key)) {
boolean updateValue =
("true".equalsIgnoreCase(value))
? true
: false;
setDelayUpdate(updateValue);
} else if ("seldirs".equals(key)) {
boolean sdValue =
("true".equalsIgnoreCase(value))
? true
: false;
setSeldirs(sdValue);
} else if (key.startsWith("cache.")) {
String name = key.substring(6);
tryToSetAParameter(cache, name, value);
} else if (key.startsWith("algorithm.")) {
String name = key.substring(10);
tryToSetAParameter(algorithm, name, value);
} else if (key.startsWith("comparator.")) {
String name = key.substring(11);
tryToSetAParameter(comparator, name, value);
} else {
setError("Invalid parameter " + key);
}
}
/**
* Try to set a value on an object using reflection.
* Helper method for easier access to IntrospectionHelper.setAttribute().
* @param obj the object on which the attribute should be set
* @param name the attributename
* @param value the new value
*/
protected void tryToSetAParameter(Object obj, String name, String value) {
Project prj = (getProject() != null) ? getProject() : new Project();
IntrospectionHelper iHelper
= IntrospectionHelper.getHelper(prj, obj.getClass());
try {
iHelper.setAttribute(prj, obj, name, value);
} catch (org.apache.tools.ant.BuildException e) {
// no-op
}
}
// ----- 'beautiful' output -----
/**
* Override Object.toString().
* @return information about this selector
*/
public String toString() {
StringBuffer buf = new StringBuffer("{modifiedselector");
buf.append(" update=").append(update);
buf.append(" seldirs=").append(selectDirectories);
buf.append(" cache=").append(cache);
buf.append(" algorithm=").append(algorithm);
buf.append(" comparator=").append(comparator);
buf.append("}");
return buf.toString();
}
// ----- BuildListener interface methods -----
/**
* Signals that the last target has finished.
* @param event recieved BuildEvent
*/
public void buildFinished(BuildEvent event) {
if (getDelayUpdate()) {
saveCache();
}
}
/**
* Signals that a target has finished.
* @param event recieved BuildEvent
*/
public void targetFinished(BuildEvent event) {
if (getDelayUpdate()) {
saveCache();
}
}
/**
* Signals that a task has finished.
* @param event recieved BuildEvent
*/
public void taskFinished(BuildEvent event) {
if (getDelayUpdate()) {
saveCache();
}
}
/**
* Signals that a build has started.
* @param event recieved BuildEvent
*/
public void buildStarted(BuildEvent event) {
// no-op
}
/**
* Signals that a target is starting.
* @param event received BuildEvent
*/
public void targetStarted(BuildEvent event) {
// no-op
}
/**
* Signals that a task is starting.
* @param event recieved BuildEvent
*/
public void taskStarted(BuildEvent event) {
// no-op
}
/**
* Signals a message logging event.
* @param event recieved BuildEvent
*/
public void messageLogged(BuildEvent event) {
// no-op
}
// The EnumeratedAttributes for the three interface implementations.
// Name-Classname mapping is done in the configure() method.
/**
* Get the cache type to use.
* @return the enumerated cache type
*/
public Cache getCache() { return cache; }
/**
* Set the cache type to use.
* @param name an enumerated cache type.
*/
public void setCache(CacheName name) {
cacheName = name;
}
/**
* The enumerated type for cache.
* The values are "propertyfile".
*/
public static class CacheName extends EnumeratedAttribute {
/** @see EnumeratedAttribute#getValues() */
/** {@inheritDoc} */
public String[] getValues() {
return new String[] {"propertyfile" };
}
}
/**
* Get the algorithm type to use.
* @return the enumerated algorithm type
*/
public Algorithm getAlgorithm() { return algorithm; }
/**
* Set the algorithm type to use.
* @param name an enumerated algorithm type.
*/
public void setAlgorithm(AlgorithmName name) {
algoName = name;
}
/**
* The enumerated type for algorithm.
* The values are "hashValue", "digest" and "checksum".
*/
public static class AlgorithmName extends EnumeratedAttribute {
/** @see EnumeratedAttribute#getValues() */
/** {@inheritDoc} */
public String[] getValues() {
return new String[] {"hashvalue", "digest", "checksum" };
}
}
/**
* Get the comparator type to use.
* @return the enumerated comparator type
*/
public Comparator getComparator() { return comparator; }
/**
* Set the comparator type to use.
* @param name an enumerated comparator type.
*/
public void setComparator(ComparatorName name) {
compName = name;
}
/**
* The enumerated type for algorithm.
* The values are "equal" and "rule".
*/
public static class ComparatorName extends EnumeratedAttribute {
/** @see EnumeratedAttribute#getValues() */
/** {@inheritDoc} */
public String[] getValues() {
return new String[] {"equal", "rule" };
}
}
}
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