ANT_17_BRANCH/src/main/org/apache/tools/ant/taskdefs/Property.java - ant - Git at Google

 /*
  *  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.taskdefs;

 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URL;
 import java.util.Enumeration;
 import java.util.Properties;
 import java.util.Stack;
 import java.util.Vector;

 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.Project;
 import org.apache.tools.ant.PropertyHelper;
 import org.apache.tools.ant.Task;
 import org.apache.tools.ant.types.Path;
 import org.apache.tools.ant.types.Reference;

 /**
  * Sets a property by name, or set of properties (from file or
  * resource) in the project.  </p>
  * Properties are immutable: whoever sets a property first freezes it for the
  * rest of the build; they are most definitely not variable.
  * <p>There are five ways to set properties:</p>
  * <ul>
  *   <li>By supplying both the <i>name</i> and <i>value</i> attribute.</li>
  *   <li>By supplying both the <i>name</i> and <i>refid</i> attribute.</li>
  *   <li>By setting the <i>file</i> attribute with the filename of the property
  *     file to load. This property file has the format as defined by the file used
  *     in the class java.util.Properties.</li>
  *   <li>By setting the <i>resource</i> attribute with the resource name of the
  *     property file to load. This property file has the format as defined by the
  *     file used in the class java.util.Properties.</li>
  *   <li>By setting the <i>environment</i> attribute with a prefix to use.
  *     Properties will be defined for every environment variable by
  *     prefixing the supplied name and a period to the name of the variable.</li>
  * </ul>
  * <p>Although combinations of these ways are possible, only one should be used
  * at a time. Problems might occur with the order in which properties are set, for
  * instance.</p>
  * <p>The value part of the properties being set, might contain references to other
  * properties. These references are resolved at the time these properties are set.
  * This also holds for properties loaded from a property file.</p>
  * Properties are case sensitive.
  *
  * @since Ant 1.1
  *
  * @ant.attribute.group name="name" description="One of these, when using the name attribute"
  * @ant.attribute.group name="noname" description="One of these, when not using the name attribute"
  * @ant.task category="property"
  */
 public class Property extends Task {

     // CheckStyle:VisibilityModifier OFF - bc
     protected String name;
     protected String value;
     protected File file;
     protected URL url;
     protected String resource;
     protected Path classpath;
     protected String env;
     protected Reference ref;
     protected String prefix;
     private Project fallback;

     protected boolean userProperty; // set read-only properties
     // CheckStyle:VisibilityModifier ON

     /**
      * Constructor for Property.
      */
     public Property() {
         this(false);
     }

     /**
      * Constructor for Property.
      * @param userProperty if true this is a user property
      * @since Ant 1.5
      */
     protected Property(boolean userProperty) {
         this(userProperty, null);
     }

     /**
      * Constructor for Property.
      * @param userProperty if true this is a user property
      * @param fallback a project to use to look for references if the reference is
      *                 not in the current project
      * @since Ant 1.5
      */
     protected Property(boolean userProperty, Project fallback) {
         this.userProperty = userProperty;
         this.fallback = fallback;
     }

     /**
      * The name of the property to set.
      * @param name property name
      */
     public void setName(String name) {
         this.name = name;
     }

     /**
      * Get the property name.
      * @return the property name
      */
     public String getName() {
         return name;
     }

     /**
      * Sets the property to the absolute filename of the
      * given file. If the value of this attribute is an absolute path, it
      * is left unchanged (with / and \ characters converted to the
      * current platforms conventions). Otherwise it is taken as a path
      * relative to the project's basedir and expanded.
      * @param location path to set
      *
      * @ant.attribute group="name"
      */
     public void setLocation(File location) {
         setValue(location.getAbsolutePath());
     }

     /**
      * The value of the property.
      * @param value value to assign
      *
      * @ant.attribute group="name"
      */
     public void setValue(String value) {
         this.value = value;
     }

     /**
      * Get the property value.
      * @return the property value
      */
     public String getValue() {
         return value;
     }

     /**
      * Filename of a property file to load.
      * @param file filename
      *
      * @ant.attribute group="noname"
      */
     public void setFile(File file) {
         this.file = file;
     }

     /**
      * Get the file attribute.
      * @return the file attribute
      */
     public File getFile() {
         return file;
     }

     /**
      * The url from which to load properties.
      * @param url url string
      *
      * @ant.attribute group="noname"
      */
     public void setUrl(URL url) {
         this.url = url;
     }

     /**
      * Get the url attribute.
      * @return the url attribute
      */
     public URL getUrl() {
         return url;
     }

     /**
      * Prefix to apply to properties loaded using <code>file</code>
      * or <code>resource</code>.
      * A "." is appended to the prefix if not specified.
      * @param prefix prefix string
      * @since Ant 1.5
      */
     public void setPrefix(String prefix) {
         this.prefix = prefix;
         if (!prefix.endsWith(".")) {
             this.prefix += ".";
         }
     }

     /**
      * Get the prefix attribute.
      * @return the prefix attribute
      * @since Ant 1.5
      */
     public String getPrefix() {
         return prefix;
     }

     /**
      * Sets a reference to an Ant datatype
      * declared elsewhere.
      * Only yields reasonable results for references
      * PATH like structures or properties.
      * @param ref reference
      *
      * @ant.attribute group="name"
      */
     public void setRefid(Reference ref) {
         this.ref = ref;
     }

     /**
      * Get the refid attribute.
      * @return the refid attribute
      */
     public Reference getRefid() {
         return ref;
     }

     /**
      * The resource name of a property file to load
      * @param resource resource on classpath
      *
      * @ant.attribute group="noname"
      */
     public void setResource(String resource) {
         this.resource = resource;
     }

     /**
      * Get the resource attribute.
      * @return the resource attribute
      */
     public String getResource() {
         return resource;
     }

     /**
      * Prefix to use when retrieving environment variables.
      * Thus if you specify environment=&quot;myenv&quot;
      * you will be able to access OS-specific
      * environment variables via property names &quot;myenv.PATH&quot; or
      * &quot;myenv.TERM&quot;.
      * <p>
      * Note that if you supply a property name with a final
      * &quot;.&quot; it will not be doubled. ie environment=&quot;myenv.&quot; will still
      * allow access of environment variables through &quot;myenv.PATH&quot; and
      * &quot;myenv.TERM&quot;. This functionality is currently only implemented
      * on select platforms. Feel free to send patches to increase the number of platforms
      * this functionality is supported on ;).<br>
      * Note also that properties are case sensitive, even if the
      * environment variables on your operating system are not, e.g. it
      * will be ${env.Path} not ${env.PATH} on Windows 2000.
      * @param env prefix
      *
      * @ant.attribute group="noname"
      */
     public void setEnvironment(String env) {
         this.env = env;
     }

     /**
      * Get the environment attribute.
      * @return the environment attribute
      * @since Ant 1.5
      */
     public String getEnvironment() {
         return env;
     }

     /**
      * The classpath to use when looking up a resource.
      * @param classpath to add to any existing classpath
      */
     public void setClasspath(Path classpath) {
         if (this.classpath == null) {
             this.classpath = classpath;
         } else {
             this.classpath.append(classpath);
         }
     }

     /**
      * The classpath to use when looking up a resource.
      * @return a path to be configured
      */
     public Path createClasspath() {
         if (this.classpath == null) {
             this.classpath = new Path(getProject());
         }
         return this.classpath.createPath();
     }

     /**
      * the classpath to use when looking up a resource,
      * given as reference to a &lt;path&gt; defined elsewhere
      * @param r a reference to a classpath
      */
     public void setClasspathRef(Reference r) {
         createClasspath().setRefid(r);
     }

     /**
      * Get the classpath used when looking up a resource.
      * @return the classpath
      * @since Ant 1.5
      */
     public Path getClasspath() {
         return classpath;
     }

     /**
      * @param userProperty ignored
      * @deprecated since 1.5.x.
      *             This was never a supported feature and has been
      *             deprecated without replacement.
      * @ant.attribute ignore="true"
      */
     public void setUserProperty(boolean userProperty) {
         log("DEPRECATED: Ignoring request to set user property in Property"
             + " task.", Project.MSG_WARN);
     }

     /**
      * get the value of this property
      * @return the current value or the empty string
      */
     public String toString() {
         return value == null ? "" : value;
     }

     /**
      * set the property in the project to the value.
      * if the task was give a file, resource or env attribute
      * here is where it is loaded
      * @throws BuildException on error
      */
     public void execute() throws BuildException {
         if (getProject() == null) {
             throw new IllegalStateException("project has not been set");
         }

         if (name != null) {
             if (value == null && ref == null) {
                 throw new BuildException("You must specify value, location or "
                                          + "refid with the name attribute",
                                          getLocation());
             }
         } else {
             if (url == null && file == null && resource == null && env == null) {
                 throw new BuildException("You must specify url, file, resource or "
                                          + "environment when not using the "
                                          + "name attribute", getLocation());
             }
         }

         if (url == null && file == null && resource == null && prefix != null) {
             throw new BuildException("Prefix is only valid when loading from "
                                      + "a url, file or resource", getLocation());
         }

         if ((name != null) && (value != null)) {
             addProperty(name, value);
         }

         if (file != null) {
             loadFile(file);
         }

         if (url != null) {
             loadUrl(url);
         }

         if (resource != null) {
             loadResource(resource);
         }

         if (env != null) {
             loadEnvironment(env);
         }

         if ((name != null) && (ref != null)) {
             try {
                 addProperty(name,
                             ref.getReferencedObject(getProject()).toString());
             } catch (BuildException be) {
                 if (fallback != null) {
                     addProperty(name,
                                 ref.getReferencedObject(fallback).toString());
                 } else {
                     throw be;
                 }
             }
         }
     }

     /**
      * load properties from a url
      * @param url url to load from
      * @throws BuildException on error
      */
     protected void loadUrl(URL url) throws BuildException {
         Properties props = new Properties();
         log("Loading " + url, Project.MSG_VERBOSE);
         try {
             InputStream is = url.openStream();
             try {
                 props.load(is);
             } finally {
                 if (is != null) {
                     is.close();
                 }
             }
             addProperties(props);
         } catch (IOException ex) {
             throw new BuildException(ex, getLocation());
         }
     }


     /**
      * load properties from a file
      * @param file file to load
      * @throws BuildException on error
      */
     protected void loadFile(File file) throws BuildException {
         Properties props = new Properties();
         log("Loading " + file.getAbsolutePath(), Project.MSG_VERBOSE);
         try {
             if (file.exists()) {
                 FileInputStream  fis = null;
                 try {
                     fis = new FileInputStream(file);
                     props.load(fis);
                 } finally {
                     if (fis != null) {
                         fis.close();
                     }
                 }
                 addProperties(props);
             } else {
                 log("Unable to find property file: " + file.getAbsolutePath(),
                     Project.MSG_VERBOSE);
             }
         } catch (IOException ex) {
             throw new BuildException(ex, getLocation());
         }
     }

     /**
      * load properties from a resource in the current classpath
      * @param name name of resource to load
      */
     protected void loadResource(String name) {
         Properties props = new Properties();
         log("Resource Loading " + name, Project.MSG_VERBOSE);
         InputStream is = null;
         try {
             ClassLoader cL = null;

             if (classpath != null) {
                 cL = getProject().createClassLoader(classpath);
             } else {
                 cL = this.getClass().getClassLoader();
             }

             if (cL == null) {
                 is = ClassLoader.getSystemResourceAsStream(name);
             } else {
                 is = cL.getResourceAsStream(name);
             }

             if (is != null) {
                 props.load(is);
                 addProperties(props);
             } else {
                 log("Unable to find resource " + name, Project.MSG_WARN);
             }
         } catch (IOException ex) {
             throw new BuildException(ex, getLocation());
         } finally {
             if (is != null) {
                 try {
                     is.close();
                 } catch (IOException e) {
                     // ignore
                 }
             }
         }

     }

     /**
      * load the environment values
      * @param prefix prefix to place before them
      */
     protected void loadEnvironment(String prefix) {
         Properties props = new Properties();
         if (!prefix.endsWith(".")) {
             prefix += ".";
         }
         log("Loading Environment " + prefix, Project.MSG_VERBOSE);
         Vector osEnv = Execute.getProcEnvironment();
         for (Enumeration e = osEnv.elements(); e.hasMoreElements();) {
             String entry = (String) e.nextElement();
             int pos = entry.indexOf('=');
             if (pos == -1) {
                 log("Ignoring: " + entry, Project.MSG_WARN);
             } else {
                 props.put(prefix + entry.substring(0, pos),
                 entry.substring(pos + 1));
             }
         }
         addProperties(props);
     }

     /**
      * iterate through a set of properties,
      * resolve them then assign them
      * @param props the properties to iterate over
      */
     protected void addProperties(Properties props) {
         resolveAllProperties(props);
         Enumeration e = props.keys();
         while (e.hasMoreElements()) {
             String propertyName = (String) e.nextElement();
             String propertyValue = props.getProperty(propertyName);

             String v = getProject().replaceProperties(propertyValue);

             if (prefix != null) {
                 propertyName = prefix + propertyName;
             }

             addProperty(propertyName, v);
         }
     }

     /**
      * add a name value pair to the project property set
      * @param n name of property
      * @param v value to set
      */
     protected void addProperty(String n, String v) {
         if (userProperty) {
             if (getProject().getUserProperty(n) == null) {
                 getProject().setInheritedProperty(n, v);
             } else {
                 log("Override ignored for " + n, Project.MSG_VERBOSE);
             }
         } else {
             getProject().setNewProperty(n, v);
         }
     }

     /**
      * resolve properties inside a properties hashtable
      * @param props properties object to resolve
      */
     private void resolveAllProperties(Properties props) throws BuildException {
         for (Enumeration e = props.keys(); e.hasMoreElements();) {
             String propertyName = (String) e.nextElement();
             Stack referencesSeen = new Stack();
             resolve(props, propertyName, referencesSeen);
         }
     }

     /**
      * Recursively expand the named property using the project's
      * reference table and the given set of properties - fail if a
      * circular definition is detected.
      *
      * @param props properties object to resolve
      * @param name of the property to resolve
      * @param referencesSeen stack of all property names that have
      * been tried to expand before coming here.
      */
     private void resolve(Properties props, String name, Stack referencesSeen)
         throws BuildException {
         if (referencesSeen.contains(name)) {
             throw new BuildException("Property " + name + " was circularly "
                                      + "defined.");
         }

         String propertyValue = props.getProperty(name);
         Vector fragments = new Vector();
         Vector propertyRefs = new Vector();
         PropertyHelper.getPropertyHelper(
             this.getProject()).parsePropertyString(
                 propertyValue, fragments, propertyRefs);

         if (propertyRefs.size() != 0) {
             referencesSeen.push(name);
             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();
                     fragment = getProject().getProperty(propertyName);
                     if (fragment == null) {
                         if (props.containsKey(propertyName)) {
                             resolve(props, propertyName, referencesSeen);
                             fragment = props.getProperty(propertyName);
                         } else {
                             fragment = "${" + propertyName + "}";
                         }
                     }
                 }
                 sb.append(fragment);
             }
             propertyValue = sb.toString();
             props.put(name, propertyValue);
             referencesSeen.pop();
         }
     }
 }
	/*
	* 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.taskdefs;

	import java.io.File;
	import java.io.FileInputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.net.URL;
	import java.util.Enumeration;
	import java.util.Properties;
	import java.util.Stack;
	import java.util.Vector;

	import org.apache.tools.ant.BuildException;
	import org.apache.tools.ant.Project;
	import org.apache.tools.ant.PropertyHelper;
	import org.apache.tools.ant.Task;
	import org.apache.tools.ant.types.Path;
	import org.apache.tools.ant.types.Reference;

	/**
	* Sets a property by name, or set of properties (from file or
	* resource) in the project. </p>
	* Properties are immutable: whoever sets a property first freezes it for the
	* rest of the build; they are most definitely not variable.
	* <p>There are five ways to set properties:</p>
	* <ul>
	* <li>By supplying both the <i>name</i> and <i>value</i> attribute.</li>
	* <li>By supplying both the <i>name</i> and <i>refid</i> attribute.</li>
	* <li>By setting the <i>file</i> attribute with the filename of the property
	* file to load. This property file has the format as defined by the file used
	* in the class java.util.Properties.</li>
	* <li>By setting the <i>resource</i> attribute with the resource name of the
	* property file to load. This property file has the format as defined by the
	* file used in the class java.util.Properties.</li>
	* <li>By setting the <i>environment</i> attribute with a prefix to use.
	* Properties will be defined for every environment variable by
	* prefixing the supplied name and a period to the name of the variable.</li>
	* </ul>
	* <p>Although combinations of these ways are possible, only one should be used
	* at a time. Problems might occur with the order in which properties are set, for
	* instance.</p>
	* <p>The value part of the properties being set, might contain references to other
	* properties. These references are resolved at the time these properties are set.
	* This also holds for properties loaded from a property file.</p>
	* Properties are case sensitive.
	*
	* @since Ant 1.1
	*
	* @ant.attribute.group name="name" description="One of these, when using the name attribute"
	* @ant.attribute.group name="noname" description="One of these, when not using the name attribute"
	* @ant.task category="property"
	*/
	public class Property extends Task {

	// CheckStyle:VisibilityModifier OFF - bc
	protected String name;
	protected String value;
	protected File file;
	protected URL url;
	protected String resource;
	protected Path classpath;
	protected String env;
	protected Reference ref;
	protected String prefix;
	private Project fallback;

	protected boolean userProperty; // set read-only properties
	// CheckStyle:VisibilityModifier ON

	/**
	* Constructor for Property.
	*/
	public Property() {
	this(false);
	}

	/**
	* Constructor for Property.
	* @param userProperty if true this is a user property
	* @since Ant 1.5
	*/
	protected Property(boolean userProperty) {
	this(userProperty, null);
	}

	/**
	* Constructor for Property.
	* @param userProperty if true this is a user property
	* @param fallback a project to use to look for references if the reference is
	* not in the current project
	* @since Ant 1.5
	*/
	protected Property(boolean userProperty, Project fallback) {
	this.userProperty = userProperty;
	this.fallback = fallback;
	}

	/**
	* The name of the property to set.
	* @param name property name
	*/
	public void setName(String name) {
	this.name = name;
	}

	/**
	* Get the property name.
	* @return the property name
	*/
	public String getName() {
	return name;
	}

	/**
	* Sets the property to the absolute filename of the
	* given file. If the value of this attribute is an absolute path, it
	* is left unchanged (with / and \ characters converted to the
	* current platforms conventions). Otherwise it is taken as a path
	* relative to the project's basedir and expanded.
	* @param location path to set
	*
	* @ant.attribute group="name"
	*/
	public void setLocation(File location) {
	setValue(location.getAbsolutePath());
	}

	/**
	* The value of the property.
	* @param value value to assign
	*
	* @ant.attribute group="name"
	*/
	public void setValue(String value) {
	this.value = value;
	}

	/**
	* Get the property value.
	* @return the property value
	*/
	public String getValue() {
	return value;
	}

	/**
	* Filename of a property file to load.
	* @param file filename
	*
	* @ant.attribute group="noname"
	*/
	public void setFile(File file) {
	this.file = file;
	}

	/**
	* Get the file attribute.
	* @return the file attribute
	*/
	public File getFile() {
	return file;
	}

	/**
	* The url from which to load properties.
	* @param url url string
	*
	* @ant.attribute group="noname"
	*/
	public void setUrl(URL url) {
	this.url = url;
	}

	/**
	* Get the url attribute.
	* @return the url attribute
	*/
	public URL getUrl() {
	return url;
	}

	/**
	* Prefix to apply to properties loaded using <code>file</code>
	* or <code>resource</code>.
	* A "." is appended to the prefix if not specified.
	* @param prefix prefix string
	* @since Ant 1.5
	*/
	public void setPrefix(String prefix) {
	this.prefix = prefix;
	if (!prefix.endsWith(".")) {
	this.prefix += ".";
	}
	}

	/**
	* Get the prefix attribute.
	* @return the prefix attribute
	* @since Ant 1.5
	*/
	public String getPrefix() {
	return prefix;
	}

	/**
	* Sets a reference to an Ant datatype
	* declared elsewhere.
	* Only yields reasonable results for references
	* PATH like structures or properties.
	* @param ref reference
	*
	* @ant.attribute group="name"
	*/
	public void setRefid(Reference ref) {
	this.ref = ref;
	}

	/**
	* Get the refid attribute.
	* @return the refid attribute
	*/
	public Reference getRefid() {
	return ref;
	}

	/**
	* The resource name of a property file to load
	* @param resource resource on classpath
	*
	* @ant.attribute group="noname"
	*/
	public void setResource(String resource) {
	this.resource = resource;
	}

	/**
	* Get the resource attribute.
	* @return the resource attribute
	*/
	public String getResource() {
	return resource;
	}

	/**
	* Prefix to use when retrieving environment variables.
	* Thus if you specify environment="myenv"
	* you will be able to access OS-specific
	* environment variables via property names "myenv.PATH" or
	* "myenv.TERM".
	* <p>
	* Note that if you supply a property name with a final
	* "." it will not be doubled. ie environment="myenv." will still
	* allow access of environment variables through "myenv.PATH" and
	* "myenv.TERM". This functionality is currently only implemented
	* on select platforms. Feel free to send patches to increase the number of platforms
	* this functionality is supported on ;).<br>
	* Note also that properties are case sensitive, even if the
	* environment variables on your operating system are not, e.g. it
	* will be ${env.Path} not ${env.PATH} on Windows 2000.
	* @param env prefix
	*
	* @ant.attribute group="noname"
	*/
	public void setEnvironment(String env) {
	this.env = env;
	}

	/**
	* Get the environment attribute.
	* @return the environment attribute
	* @since Ant 1.5
	*/
	public String getEnvironment() {
	return env;
	}

	/**
	* The classpath to use when looking up a resource.
	* @param classpath to add to any existing classpath
	*/
	public void setClasspath(Path classpath) {
	if (this.classpath == null) {
	this.classpath = classpath;
	} else {
	this.classpath.append(classpath);
	}
	}

	/**
	* The classpath to use when looking up a resource.
	* @return a path to be configured
	*/
	public Path createClasspath() {
	if (this.classpath == null) {
	this.classpath = new Path(getProject());
	}
	return this.classpath.createPath();
	}

	/**
	* the classpath to use when looking up a resource,
	* given as reference to a <path> defined elsewhere
	* @param r a reference to a classpath
	*/
	public void setClasspathRef(Reference r) {
	createClasspath().setRefid(r);
	}

	/**
	* Get the classpath used when looking up a resource.
	* @return the classpath
	* @since Ant 1.5
	*/
	public Path getClasspath() {
	return classpath;
	}

	/**
	* @param userProperty ignored
	* @deprecated since 1.5.x.
	* This was never a supported feature and has been
	* deprecated without replacement.
	* @ant.attribute ignore="true"
	*/
	public void setUserProperty(boolean userProperty) {
	log("DEPRECATED: Ignoring request to set user property in Property"
	+ " task.", Project.MSG_WARN);
	}

	/**
	* get the value of this property
	* @return the current value or the empty string
	*/
	public String toString() {
	return value == null ? "" : value;
	}

	/**
	* set the property in the project to the value.
	* if the task was give a file, resource or env attribute
	* here is where it is loaded
	* @throws BuildException on error
	*/
	public void execute() throws BuildException {
	if (getProject() == null) {
	throw new IllegalStateException("project has not been set");
	}

	if (name != null) {
	if (value == null && ref == null) {
	throw new BuildException("You must specify value, location or "
	+ "refid with the name attribute",
	getLocation());
	}
	} else {
	if (url == null && file == null && resource == null && env == null) {
	throw new BuildException("You must specify url, file, resource or "
	+ "environment when not using the "
	+ "name attribute", getLocation());
	}
	}

	if (url == null && file == null && resource == null && prefix != null) {
	throw new BuildException("Prefix is only valid when loading from "
	+ "a url, file or resource", getLocation());
	}

	if ((name != null) && (value != null)) {
	addProperty(name, value);
	}

	if (file != null) {
	loadFile(file);
	}

	if (url != null) {
	loadUrl(url);
	}

	if (resource != null) {
	loadResource(resource);
	}

	if (env != null) {
	loadEnvironment(env);
	}

	if ((name != null) && (ref != null)) {
	try {
	addProperty(name,
	ref.getReferencedObject(getProject()).toString());
	} catch (BuildException be) {
	if (fallback != null) {
	addProperty(name,
	ref.getReferencedObject(fallback).toString());
	} else {
	throw be;
	}
	}
	}
	}

	/**
	* load properties from a url
	* @param url url to load from
	* @throws BuildException on error
	*/
	protected void loadUrl(URL url) throws BuildException {
	Properties props = new Properties();
	log("Loading " + url, Project.MSG_VERBOSE);
	try {
	InputStream is = url.openStream();
	try {
	props.load(is);
	} finally {
	if (is != null) {
	is.close();
	}
	}
	addProperties(props);
	} catch (IOException ex) {
	throw new BuildException(ex, getLocation());
	}
	}


	/**
	* load properties from a file
	* @param file file to load
	* @throws BuildException on error
	*/
	protected void loadFile(File file) throws BuildException {
	Properties props = new Properties();
	log("Loading " + file.getAbsolutePath(), Project.MSG_VERBOSE);
	try {
	if (file.exists()) {
	FileInputStream fis = null;
	try {
	fis = new FileInputStream(file);
	props.load(fis);
	} finally {
	if (fis != null) {
	fis.close();
	}
	}
	addProperties(props);
	} else {
	log("Unable to find property file: " + file.getAbsolutePath(),
	Project.MSG_VERBOSE);
	}
	} catch (IOException ex) {
	throw new BuildException(ex, getLocation());
	}
	}

	/**
	* load properties from a resource in the current classpath
	* @param name name of resource to load
	*/
	protected void loadResource(String name) {
	Properties props = new Properties();
	log("Resource Loading " + name, Project.MSG_VERBOSE);
	InputStream is = null;
	try {
	ClassLoader cL = null;

	if (classpath != null) {
	cL = getProject().createClassLoader(classpath);
	} else {
	cL = this.getClass().getClassLoader();
	}

	if (cL == null) {
	is = ClassLoader.getSystemResourceAsStream(name);
	} else {
	is = cL.getResourceAsStream(name);
	}

	if (is != null) {
	props.load(is);
	addProperties(props);
	} else {
	log("Unable to find resource " + name, Project.MSG_WARN);
	}
	} catch (IOException ex) {
	throw new BuildException(ex, getLocation());
	} finally {
	if (is != null) {
	try {
	is.close();
	} catch (IOException e) {
	// ignore
	}
	}
	}

	}

	/**
	* load the environment values
	* @param prefix prefix to place before them
	*/
	protected void loadEnvironment(String prefix) {
	Properties props = new Properties();
	if (!prefix.endsWith(".")) {
	prefix += ".";
	}
	log("Loading Environment " + prefix, Project.MSG_VERBOSE);
	Vector osEnv = Execute.getProcEnvironment();
	for (Enumeration e = osEnv.elements(); e.hasMoreElements();) {
	String entry = (String) e.nextElement();
	int pos = entry.indexOf('=');
	if (pos == -1) {
	log("Ignoring: " + entry, Project.MSG_WARN);
	} else {
	props.put(prefix + entry.substring(0, pos),
	entry.substring(pos + 1));
	}
	}
	addProperties(props);
	}

	/**
	* iterate through a set of properties,
	* resolve them then assign them
	* @param props the properties to iterate over
	*/
	protected void addProperties(Properties props) {
	resolveAllProperties(props);
	Enumeration e = props.keys();
	while (e.hasMoreElements()) {
	String propertyName = (String) e.nextElement();
	String propertyValue = props.getProperty(propertyName);

	String v = getProject().replaceProperties(propertyValue);

	if (prefix != null) {
	propertyName = prefix + propertyName;
	}

	addProperty(propertyName, v);
	}
	}

	/**
	* add a name value pair to the project property set
	* @param n name of property
	* @param v value to set
	*/
	protected void addProperty(String n, String v) {
	if (userProperty) {
	if (getProject().getUserProperty(n) == null) {
	getProject().setInheritedProperty(n, v);
	} else {
	log("Override ignored for " + n, Project.MSG_VERBOSE);
	}
	} else {
	getProject().setNewProperty(n, v);
	}
	}

	/**
	* resolve properties inside a properties hashtable
	* @param props properties object to resolve
	*/
	private void resolveAllProperties(Properties props) throws BuildException {
	for (Enumeration e = props.keys(); e.hasMoreElements();) {
	String propertyName = (String) e.nextElement();
	Stack referencesSeen = new Stack();
	resolve(props, propertyName, referencesSeen);
	}
	}

	/**
	* Recursively expand the named property using the project's
	* reference table and the given set of properties - fail if a
	* circular definition is detected.
	*
	* @param props properties object to resolve
	* @param name of the property to resolve
	* @param referencesSeen stack of all property names that have
	* been tried to expand before coming here.
	*/
	private void resolve(Properties props, String name, Stack referencesSeen)
	throws BuildException {
	if (referencesSeen.contains(name)) {
	throw new BuildException("Property " + name + " was circularly "
	+ "defined.");
	}

	String propertyValue = props.getProperty(name);
	Vector fragments = new Vector();
	Vector propertyRefs = new Vector();
	PropertyHelper.getPropertyHelper(
	this.getProject()).parsePropertyString(
	propertyValue, fragments, propertyRefs);

	if (propertyRefs.size() != 0) {
	referencesSeen.push(name);
	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();
	fragment = getProject().getProperty(propertyName);
	if (fragment == null) {
	if (props.containsKey(propertyName)) {
	resolve(props, propertyName, referencesSeen);
	fragment = props.getProperty(propertyName);
	} else {
	fragment = "${" + propertyName + "}";
	}
	}
	}
	sb.append(fragment);
	}
	propertyValue = sb.toString();
	props.put(name, propertyValue);
	referencesSeen.pop();
	}
	}
	}