| /* |
| * The Apache Software License, Version 1.1 |
| * |
| * Copyright (c) 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 "The Jakarta Project", "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.types; |
| import java.util.Stack; |
| import org.apache.tools.ant.BuildException; |
| import org.apache.tools.ant.Project; |
| |
| import org.apache.tools.ant.ProjectComponent; |
| |
| /** |
| * Ant1 DataType facade |
| * |
| * @author <a href="mailto:conor@apache.org">Conor MacNeill</a> |
| * @created 31 January 2002 |
| */ |
| public abstract class DataType extends ProjectComponent |
| implements org.apache.ant.common.antlib.DataType { |
| |
| /** The description the user has set. */ |
| protected String description = null; |
| /** Value to the refid attribute. */ |
| protected Reference ref = null; |
| /** |
| * Are we sure we don't hold circular references? <p> |
| * |
| * Subclasses are responsible for setting this value to false if we'd |
| * need to investigate this condition (usually because a child element |
| * has been added that is a subclass of DataType).</p> |
| */ |
| protected boolean checked = true; |
| |
| /** |
| * Sets a description of the current data type. It will be useful in |
| * commenting what we are doing. |
| * |
| * @param desc the new description value |
| */ |
| public void setDescription(String desc) { |
| description = desc; |
| } |
| |
| /** |
| * Set the value of the refid attribute. <p> |
| * |
| * Subclasses may need to check whether any other attributes have been |
| * set as well or child elements have been created and thus override |
| * this method. if they do the must call <code>super.setRefid</code>. |
| * </p> |
| * |
| * @param ref the new refid value |
| */ |
| public void setRefid(Reference ref) { |
| this.ref = ref; |
| checked = false; |
| } |
| |
| /** |
| * Sets the id of the DataType |
| * |
| * @param id the name under which the data type is to be referenced |
| */ |
| public void setId(String id) { |
| project.addReference(id, this); |
| } |
| |
| /** |
| * Return the description for the current data type. |
| * |
| * @return the data type's description |
| */ |
| public String getDescription() { |
| return description; |
| } |
| |
| /** |
| * Has the refid attribute of this element been set? |
| * |
| * @return true if this data type is a refeence to another instance |
| */ |
| public boolean isReference() { |
| return ref != null; |
| } |
| |
| /** Validate this component */ |
| public void validateComponent() { |
| // no default validation for Ant1 types |
| } |
| |
| |
| /** |
| * Performs the check for circular references and returns the referenced |
| * object. |
| * |
| * @param requiredClass the class which the object being referenced must |
| * support |
| * @param dataTypeName the name of the data type |
| * @return the refenced object |
| */ |
| protected Object getCheckedRef(Class requiredClass, String dataTypeName) { |
| if (!checked) { |
| Stack stk = new Stack(); |
| stk.push(this); |
| dieOnCircularReference(stk, getProject()); |
| } |
| |
| Object o = ref.getReferencedObject(getProject()); |
| if (!(requiredClass.isAssignableFrom(o.getClass()))) { |
| String msg = ref.getRefId() + " doesn\'t denote a " + dataTypeName; |
| throw new BuildException(msg); |
| } else { |
| return o; |
| } |
| } |
| |
| /** |
| * Check to see whether any DataType we hold references to is included |
| * in the Stack (which holds all DataType instances that directly or |
| * indirectly reference this instance, including this instance itself). |
| * <p> |
| * |
| * If one is included, throw a BuildException created by {@link |
| * #circularReference circularReference}.</p> <p> |
| * |
| * This implementation is appropriate only for a DataType that cannot |
| * hold other DataTypes as children.</p> <p> |
| * |
| * The general contract of this method is that it shouldn't do anything |
| * if {@link #checked <code>checked</code>} is true and set it to true |
| * on exit.</p> |
| * |
| * @param stk stack used to check for a circular reference |
| * @param p the project |
| * @exception BuildException if this data type is a reference to an |
| * instance which depends on this data type |
| */ |
| protected void dieOnCircularReference(Stack stk, Project p) |
| throws BuildException { |
| |
| if (checked || !isReference()) { |
| return; |
| } |
| Object o = ref.getReferencedObject(p); |
| |
| if (o instanceof DataType) { |
| if (stk.contains(o)) { |
| throw circularReference(); |
| } else { |
| stk.push(o); |
| ((DataType)o).dieOnCircularReference(stk, p); |
| stk.pop(); |
| } |
| } |
| checked = true; |
| } |
| |
| /** |
| * Creates an exception that indicates that refid has to be the only |
| * attribute if it is set. |
| * |
| * @return an appropriate excpetion instance |
| */ |
| protected BuildException tooManyAttributes() { |
| return new BuildException("You must not specify more than " |
| + "one attribute when using refid"); |
| } |
| |
| /** |
| * Creates an exception that indicates that this XML element must not |
| * have child elements if the refid attribute is set. |
| * |
| * @return an appropriate excpetion instance |
| */ |
| protected BuildException noChildrenAllowed() { |
| return new BuildException("You must not specify nested " |
| + "elements when using refid"); |
| } |
| |
| /** |
| * Creates an exception that indicates the user has generated a loop of |
| * data types referencing each other. |
| * |
| * @return an appropriate excpetion instance |
| */ |
| protected BuildException circularReference() { |
| return new BuildException("This data type contains a " |
| + "circular reference."); |
| } |
| } |
| |
