/*
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000-2002 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 acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "Ant" 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 apache@apache.org.
*
* 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 Group.
*
* 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/>.
*/
package org.apache.tools.ant;
import java.io.File;
import java.io.InputStream;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Hashtable;
import java.util.Vector;
import java.util.Enumeration;
import java.util.Locale;
import org.xml.sax.AttributeList;
import org.apache.tools.ant.helper.ProjectHelperImpl;
import org.apache.tools.ant.util.LoaderUtils;
/**
* Configures a Project (complete with Targets and Tasks) based on
* a XML build file. It'll rely on a plugin to do the actual processing
* of the xml file.
*
* This class also provide static wrappers for common introspection.
*
* All helper plugins must provide backward compatiblity with the
* original ant patterns, unless a different behavior is explicitely
* specified. For example, if namespace is used on the <project> tag
* the helper can expect the entire build file to be namespace-enabled.
* Namespaces or helper-specific tags can provide meta-information to
* the helper, allowing it to use new ( or different policies ).
*
* However, if no namespace is used the behavior should be exactly
* identical with the default helper.
*
* @author duncan@x180.com
*/
public class ProjectHelper {
/**
* Name of JVM system property which provides the name of the
* ProjectHelper class to use.
*/
public static final String HELPER_PROPERTY =
"org.apache.tools.ant.ProjectHelper";
/**
* The service identifier in jars which provide Project Helper
* implementations.
*/
public static final String SERVICE_ID =
"META-INF/services/org.apache.tools.ant.ProjectHelper";
/**
* Configures the project with the contents of the specified XML file.
*
* @param project The project to configure. Must not be <code>null</code>.
* @param buildFile An XML file giving the project's configuration.
* Must not be <code>null</code>.
*
* @exception BuildException if the configuration is invalid or cannot
* be read
*/
public static void configureProject(Project project, File buildFile)
throws BuildException {
ProjectHelper helper = ProjectHelper.getProjectHelper();
helper.parse(project, buildFile);
}
/** Default constructor */
public ProjectHelper() {
}
/**
* Parses the project file, configuring the project as it goes.
*
* @param project The project for the resulting ProjectHelper to configure.
* Must not be <code>null</code>.
* @param source The source for XML configuration. A helper must support
* at least File, for backward compatibility. Helpers may
* support URL, InputStream, etc or specialized types.
*
* @since Ant1.5
* @exception BuildException if the configuration is invalid or cannot
* be read
*/
public void parse(Project project, Object source) throws BuildException {
throw new BuildException("ProjectHelper.parse() must be implemented "
+ "in a helper plugin " + this.getClass().getName());
}
/**
* Discovers a project helper instance. Uses the same patterns
* as JAXP, commons-logging, etc: a system property, a JDK1.3
* service discovery, default.
*
* @return a ProjectHelper, either a custom implementation
* if one is available and configured, or the default implementation
* otherwise.
*
* @exception BuildException if a specified helper class cannot
* be loaded/instantiated.
*/
public static ProjectHelper getProjectHelper()
throws BuildException {
// Identify the class loader we will be using. Ant may be
// in a webapp or embeded in a different app
ProjectHelper helper = null;
// First, try the system property
String helperClass = System.getProperty(HELPER_PROPERTY);
try {
if (helperClass != null) {
helper = newHelper(helperClass);
}
} catch (SecurityException e) {
System.out.println("Unable to load ProjectHelper class \""
+ helperClass + " specified in system property "
+ HELPER_PROPERTY);
}
// A JDK1.3 'service' ( like in JAXP ). That will plug a helper
// automatically if in CLASSPATH, with the right META-INF/services.
if (helper == null) {
try {
ClassLoader classLoader = getContextClassLoader();
InputStream is = null;
if (classLoader != null) {
is = classLoader.getResourceAsStream(SERVICE_ID);
}
if (is == null) {
is = ClassLoader.getSystemResourceAsStream(SERVICE_ID);
}
if (is != null) {
// This code is needed by EBCDIC and other strange systems.
// It's a fix for bugs reported in xerces
InputStreamReader isr;
try {
isr = new InputStreamReader(is, "UTF-8");
} catch (java.io.UnsupportedEncodingException e) {
isr = new InputStreamReader(is);
}
BufferedReader rd = new BufferedReader(isr);
String helperClassName = rd.readLine();
rd.close();
if (helperClassName != null &&
!"".equals(helperClassName)) {
helper = newHelper(helperClassName);
}
}
} catch (Exception ex) {
System.out.println("Unable to load ProjectHelper "
+ "from service \"" + SERVICE_ID);
}
}
if (helper != null) {
return helper;
} else {
try {
// Default
return new ProjectHelperImpl();
} catch (Throwable e) {
String message = "Unable to load default ProjectHelper due to "
+ e.getClass().getName() + ": " + e.getMessage();
throw new BuildException(message, e);
}
}
}
/**
* Creates a new helper instance from the name of the class.
* It'll first try the thread class loader, then Class.forName()
* will load from the same loader that loaded this class.
*
* @param helperClass The name of the class to create an instance
* of. Must not be <code>null</code>.
*
* @return a new instance of the specified class.
*
* @exception BuildException if the class cannot be found or
* cannot be appropriate instantiated.
*/
private static ProjectHelper newHelper(String helperClass)
throws BuildException {
ClassLoader classLoader = getContextClassLoader();
try {
Class clazz = null;
if (classLoader != null) {
try {
clazz = classLoader.loadClass(helperClass);
} catch (ClassNotFoundException ex) {
// try next method
}
}
if (clazz == null) {
clazz = Class.forName(helperClass);
}
return ((ProjectHelper) clazz.newInstance());
} catch (Exception e) {
throw new BuildException(e);
}
}
/**
* JDK1.1 compatible access to the context class loader.
* Cut&paste from JAXP.
*
* @return the current context class loader, or <code>null</code>
* if the context class loader is unavailable.
*/
public static ClassLoader getContextClassLoader() {
if (!LoaderUtils.isContextLoaderAvailable()) {
return null;
}
return LoaderUtils.getContextClassLoader();
}
// -------------------- Static utils, used by most helpers ----------------
/**
* Configures an object using an introspection handler.
*
* @param target The target object to be configured.
* Must not be <code>null</code>.
* @param attrs A list of attributes to configure within the target.
* Must not be <code>null</code>.
* @param project The project containing the target.
* Must not be <code>null</code>.
*
* @exception BuildException if any of the attributes can't be handled by
* the target
*/
public static void configure(Object target, AttributeList attrs,
Project project) throws BuildException {
if (target instanceof TaskAdapter) {
target = ((TaskAdapter) target).getProxy();
}
IntrospectionHelper ih =
IntrospectionHelper.getHelper(target.getClass());
project.addBuildListener(ih);
for (int i = 0; i < attrs.getLength(); i++) {
// reflect these into the target
String value = replaceProperties(project, attrs.getValue(i),
project.getProperties());
try {
ih.setAttribute(project, target,
attrs.getName(i).toLowerCase(Locale.US), value);
} catch (BuildException be) {
// id attribute must be set externally
if (!attrs.getName(i).equals("id")) {
throw be;
}
}
}
}
/**
* Adds the content of #PCDATA sections to an element.
*
* @param project The project containing the target.
* Must not be <code>null</code>.
* @param target The target object to be configured.
* Must not be <code>null</code>.
* @param buf A character array of the text within the element.
* Will not be <code>null</code>.
* @param start The start element in the array.
* @param count The number of characters to read from the array.
*
* @exception BuildException if the target object doesn't accept text
*/
public static void addText(Project project, Object target, char[] buf,
int start, int count) throws BuildException {
addText(project, target, new String(buf, start, count));
}
/**
* Adds the content of #PCDATA sections to an element.
*
* @param project The project containing the target.
* Must not be <code>null</code>.
* @param target The target object to be configured.
* Must not be <code>null</code>.
* @param text Text to add to the target.
* May be <code>null</code>, in which case this
* method call is a no-op.
*
* @exception BuildException if the target object doesn't accept text
*/
public static void addText(Project project, Object target, String text)
throws BuildException {
if (text == null) {
return;
}
if (target instanceof TaskAdapter) {
target = ((TaskAdapter) target).getProxy();
}
IntrospectionHelper.getHelper(target.getClass()).addText(project,
target, text);
}
/**
* Stores a configured child element within its parent object.
*
* @param project Project containing the objects.
* May be <code>null</code>.
* @param parent Parent object to add child to.
* Must not be <code>null</code>.
* @param child Child object to store in parent.
* Should not be <code>null</code>.
* @param tag Name of element which generated the child.
* May be <code>null</code>, in which case
* the child is not stored.
*/
public static void storeChild(Project project, Object parent,
Object child, String tag) {
IntrospectionHelper ih
= IntrospectionHelper.getHelper(parent.getClass());
ih.storeElement(project, parent, child, tag);
}
/**
* Replaces <code>${xxx}</code> style constructions in the given value with
* the string value of the corresponding properties.
*
* @param project The project containing the properties to replace.
* Must not be <code>null</code>.
*
* @param value The string to be scanned for property references.
* May be <code>null</code>.
*
* @exception BuildException if the string contains an opening
* <code>${</code> without a closing
* <code>}</code>
* @return the original string with the properties replaced, or
* <code>null</code> if the original string is <code>null</code>.
*
* @since 1.5
*/
public static String replaceProperties(Project project, String value)
throws BuildException {
return project.replaceProperties(value);
}
/**
* Replaces <code>${xxx}</code> style constructions in the given value
* with the string value of the corresponding data types.
*
* @param project The container project. This is used solely for
* logging purposes. Must not be <code>null</code>.
* @param value The string to be scanned for property references.
* May be <code>null</code>, in which case this
* method returns immediately with no effect.
* @param keys Mapping (String to String) of property names to their
* values. Must not be <code>null</code>.
*
* @exception BuildException if the string contains an opening
* <code>${</code> without a closing
* <code>}</code>
* @return the original string with the properties replaced, or
* <code>null</code> if the original string is <code>null</code>.
*/
public static String replaceProperties(Project project, String value,
Hashtable keys) throws BuildException {
if (value == null) {
return null;
}
Vector fragments = new Vector();
Vector propertyRefs = new Vector();
parsePropertyString(value, fragments, propertyRefs);
StringBuffer sb = new StringBuffer();
Enumeration i = fragments.elements();
Enumeration j = propertyRefs.elements();
while (i.hasMoreElements()) {
String fragment = (String) i.nextElement();
if (fragment == null) {
String propertyName = (String) j.nextElement();
if (!keys.containsKey(propertyName)) {
project.log("Property ${" + propertyName
+ "} has not been set", Project.MSG_VERBOSE);
}
fragment = (keys.containsKey(propertyName))
? (String) keys.get(propertyName)
: "${" + propertyName + "}";
}
sb.append(fragment);
}
return sb.toString();
}
/**
* Parses a string containing <code>${xxx}</code> style property
* references into two lists. The first list is a collection
* of text fragments, while the other is a set of string property names.
* <code>null</code> entries in the first list indicate a property
* reference from the second list.
*
* @param value Text to parse. Must not be <code>null</code>.
* @param fragments List to add text fragments to.
* Must not be <code>null</code>.
* @param propertyRefs List to add property names to.
* Must not be <code>null</code>.
*
* @exception BuildException if the string contains an opening
* <code>${</code> without a closing
* <code>}</code>
*/
public static void parsePropertyString(String value, Vector fragments,
Vector propertyRefs)
throws BuildException {
int prev = 0;
int pos;
//search for the next instance of $ from the 'prev' position
while ((pos = value.indexOf("$", prev)) >= 0) {
//if there was any text before this, add it as a fragment
//TODO, this check could be modified to go if pos>prev;
//seems like this current version could stick empty strings
//into the list
if (pos > 0) {
fragments.addElement(value.substring(prev, pos));
}
//if we are at the end of the string, we tack on a $
//then move past it
if (pos == (value.length() - 1)) {
fragments.addElement("$");
prev = pos + 1;
} else if (value.charAt(pos + 1) != '{') {
//peek ahead to see if the next char is a property or not
//not a property: insert the char as a literal
/*
fragments.addElement(value.substring(pos + 1, pos + 2));
prev = pos + 2;
*/
if (value.charAt(pos + 1) == '$') {
//backwards compatibility two $ map to one mode
fragments.addElement("$");
prev = pos + 2;
} else {
//new behaviour: $X maps to $X for all values of X!='$'
fragments.addElement(value.substring(pos, pos + 2));
prev = pos + 2;
}
} else {
//property found, extract its name or bail on a typo
int endName = value.indexOf('}', pos);
if (endName < 0) {
throw new BuildException("Syntax error in property: "
+ value);
}
String propertyName = value.substring(pos + 2, endName);
fragments.addElement(null);
propertyRefs.addElement(propertyName);
prev = endName + 1;
}
}
//no more $ signs found
//if there is any tail to the file, append it
if (prev < value.length()) {
fragments.addElement(value.substring(prev));
}
}
//end class
}