weka.core.ResourceUtils Maven / Gradle / Ivy
Show all versions of weka-dev Show documentation
/*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see
*
*
* String classifierName = Utils.getOption('W', options);
* Classifier c = (Classifier)Utils.forName(Classifier.class,
* classifierName,
* options);
* setClassifier(c);
*
*
* @param classType the class that the instantiated object should be
* assignable to -- an exception is thrown if this is not the case
* @param className the fully qualified class name of the object
* @param options an array of options suitable for passing to setOptions. May
* be null. Any options accepted by the object will be removed from
* the array.
* @return the newly created object, ready for use (if it is an array, it will
* have size zero).
* @exception Exception if the class name is invalid, or if the class is not
* assignable to the desired class type, or the options supplied
* are not acceptable to the object
*/
public static Object forName(Class classType, String className,
String[] options) throws Exception {
if (System.getProperty("weka.test.maventest", "").equalsIgnoreCase("true")) {
return forNameNoSchemeMatch(classType, className, options);
}
List matches =
Run.findSchemeMatch(classType, className, false, true);
if (matches.size() == 0) {
// Could be an array class type, which is not covered by findSchemeMatch()
Class c = WekaPackageClassLoaderManager.forName(className);
if (c.isArray() && (classType == null || classType.isAssignableFrom(c))) {
return Array.newInstance(c.getComponentType(), 0);
}
throw new Exception("Can't find a permissible class called: " + className);
}
if (matches.size() > 1) {
StringBuffer sb =
new StringBuffer("More than one possibility matched '" + className
+ "':\n");
for (String s : matches) {
sb.append(" " + s + '\n');
}
throw new Exception(sb.toString());
}
className = matches.get(0);
Class c = null;
try {
// c = Class.forName(className);
c = WekaPackageClassLoaderManager.forName(className);
} catch (Exception ex) {
throw new Exception("Can't find a permissible class called: " + className);
}
Object o = c.newInstance();
if ((o instanceof OptionHandler) && (options != null)) {
((OptionHandler) o).setOptions(options);
Utils.checkForRemainingOptions(options);
}
return o;
}
/**
* Creates a new instance of an object given it's class name and (optional)
* arguments to pass to it's setOptions method. If the object implements
* OptionHandler and the options parameter is non-null, the object will have
* it's options set. Example use:
*
*
*
* String classifierName = Utils.getOption('W', options);
* Classifier c = (Classifier)Utils.forName(Classifier.class,
* classifierName,
* options);
* setClassifier(c);
*
*
* @param classType the class that the instantiated object should be
* assignable to -- an exception is thrown if this is not the case
* @param className the fully qualified class name of the object
* @param options an array of options suitable for passing to setOptions. May
* be null. Any options accepted by the object will be removed from
* the array.
* @return the newly created object, ready for use.
* @exception Exception if the class name is invalid, or if the class is not
* assignable to the desired class type, or the options supplied
* are not acceptable to the object
*/
@SuppressWarnings("unchecked")
protected static Object forNameNoSchemeMatch(Class classType,
String className, String[] options) throws Exception {
Class c = null;
try {
// c = Class.forName(className);
c = WekaPackageClassLoaderManager.forName(className);
} catch (Exception ex) {
throw new Exception("Can't find class called: " + className);
}
if (classType != null && !classType.isAssignableFrom(c)) {
throw new Exception(classType.getName() + " is not assignable from "
+ className);
}
Object o = c.newInstance();
if ((o instanceof OptionHandler) && (options != null)) {
((OptionHandler) o).setOptions(options);
Utils.checkForRemainingOptions(options);
}
return o;
}
/**
* Reads properties that inherit from three locations. Properties are first
* defined in the system resource location (i.e. in the CLASSPATH). These
* default properties must exist. Properties optionally defined in the user
* properties location (WekaPackageManager.PROPERTIES_DIR) override default
* settings. Properties defined in the current directory (optional) override
* all these settings.
*
* @param resourceName the location of the resource that should be loaded.
* e.g.: "weka/core/Utils.props". (The use of hardcoded forward
* slashes here is OK - see jdk1.1/docs/guide/misc/resources.html)
* This routine will also look for the file (in this case)
* "Utils.props" in the users home directory and the current
* directory.
* @return the Properties
* @exception Exception if no default properties are defined, or if an error
* occurs reading the properties files.
*/
public static Properties readProperties(String resourceName) throws Exception {
Utils utils = new Utils();
return readProperties(resourceName, utils.getClass().getClassLoader());
}
/**
* Reads properties that inherit from three locations. Properties are first
* defined in the system resource location (i.e. in the CLASSPATH). These
* default properties must exist. Properties optionally defined in the user
* properties location (WekaPackageManager.PROPERTIES_DIR) override default
* settings. Properties defined in the current directory (optional) override
* all these settings.
*
* @param resourceName the location of the resource that should be loaded.
* e.g.: "weka/core/Utils.props". (The use of hardcoded forward
* slashes here is OK - see jdk1.1/docs/guide/misc/resources.html)
* This routine will also look for the file (in this case)
* "Utils.props" in the users home directory and the current
* directory.
* @param loader the class loader to use when loading properties
* @return the Properties
* @exception Exception if no default properties are defined, or if an error
* occurs reading the properties files.
*/
public static Properties readProperties(String resourceName,
ClassLoader loader) throws Exception {
Properties defaultProps = new Properties();
try {
// Apparently hardcoded slashes are OK here
// jdk1.1/docs/guide/misc/resources.html
Enumeration urls = loader.getResources(resourceName);
boolean first = true;
while (urls.hasMoreElements()) {
URL url = urls.nextElement();
if (first) {
defaultProps.load(url.openStream());
first = false;
} else {
Properties props = new Properties(defaultProps);
props.load(url.openStream());
defaultProps = props;
}
}
} catch (Exception ex) {
System.err.println("Warning, unable to load properties file(s) from "
+ "system resource (Utils.java): " + resourceName);
}
// Hardcoded slash is OK here
// eg: see jdk1.1/docs/guide/misc/resources.html
int slInd = resourceName.lastIndexOf('/');
if (slInd != -1) {
resourceName = resourceName.substring(slInd + 1);
}
// Allow a properties file in the WekaPackageManager.PROPERTIES_DIR to
// override
Properties userProps = new Properties(defaultProps);
if (!WekaPackageManager.PROPERTIES_DIR.exists()) {
WekaPackageManager.PROPERTIES_DIR.mkdir();
}
File propFile =
new File(WekaPackageManager.PROPERTIES_DIR.toString() + File.separator
+ resourceName);
if (propFile.exists()) {
try {
userProps.load(new FileInputStream(propFile));
} catch (Exception ex) {
throw new Exception("Problem reading user properties: " + propFile);
}
}
// Allow a properties file in the current directory to override
Properties localProps = new Properties(userProps);
propFile = new File(resourceName);
if (propFile.exists()) {
try {
localProps.load(new FileInputStream(propFile));
} catch (Exception ex) {
throw new Exception("Problem reading local properties: " + propFile);
}
}
return new EnvironmentProperties(localProps);
}
/**
* Returns the Weka home directory.
*
* @return the home directory
*/
public static File getWekaHome() {
return WekaPackageManager.WEKA_HOME;
}
}