Ant example source code file (PropertySet.java)

This example Ant source code file (PropertySet.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Ant tags/keywords

buildexception, commandline, enumeration, enumeration, hashtable, iterator, mapper, propertyref, propertyref, propertyset, propertyset, string, string, util, vector

The PropertySet.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;

import java.util.Enumeration;
import java.util.Iterator;
import java.util.Map;
import java.util.HashSet;
import java.util.Set;
import java.util.TreeMap;
import java.util.Hashtable;
import java.util.Properties;
import java.util.Vector;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.types.resources.PropertyResource;
import org.apache.tools.ant.util.FileNameMapper;
import org.apache.tools.ant.util.regexp.RegexpMatcher;
import org.apache.tools.ant.util.regexp.RegexpMatcherFactory;

/**
 * A set of properties.
 *
 * @since Ant 1.6
 */
public class PropertySet extends DataType implements ResourceCollection {

    private boolean dynamic = true;
    private boolean negate = false;
    private Set cachedNames;
    private Vector ptyRefs = new Vector();
    private Vector setRefs = new Vector();
    private Mapper mapper;

    /**
     * This is a nested class containing a reference to some properties
     * and optionally a source of properties.
     */
    public static class PropertyRef {

        private int count;
        private String name;
        private String regex;
        private String prefix;
        private String builtin;

        /**
         * Set the name.
         * @param name a <code>String value.
         */
        public void setName(String name) {
            assertValid("name", name);
            this.name = name;
        }

        /**
         * Set the regular expression to use to filter the properties.
         * @param regex a regular expression.
         */
        public void setRegex(String regex) {
            assertValid("regex", regex);
            this.regex = regex;
        }

        /**
         * Set the prefix to use.
         * @param prefix a <code>String value.
         */
        public void setPrefix(String prefix) {
            assertValid("prefix", prefix);
            this.prefix = prefix;
        }

        /**
         * Builtin property names - all, system or commandline.
         * @param b an enumerated <code>BuildinPropertySetName value.
         */
        public void setBuiltin(BuiltinPropertySetName b) {
            String pBuiltIn = b.getValue();
            assertValid("builtin", pBuiltIn);
            this.builtin = pBuiltIn;
        }

        private void assertValid(String attr, String value) {
            if (value == null || value.length() < 1) {
                throw new BuildException("Invalid attribute: " + attr);
            }

            if (++count != 1) {
                throw new BuildException("Attributes name, regex, and "
                    + "prefix are mutually exclusive");
            }
        }

        /**
         * A debug toString().
         * @return a string version of this object.
         */
        public String toString() {
            return "name=" + name + ", regex=" + regex + ", prefix=" + prefix
                + ", builtin=" + builtin;
        }

    } //end nested class

    /**
     * Allow properties of a particular name in the set.
     * @param name the property name to allow.
     */
    public void appendName(String name) {
        PropertyRef r = new PropertyRef();
        r.setName(name);
        addPropertyref(r);
    }

    /**
     * Allow properties whose names match a regex in the set.
     * @param regex the regular expression to use.
     */
    public void appendRegex(String regex) {
        PropertyRef r = new PropertyRef();
        r.setRegex(regex);
        addPropertyref(r);
    }

    /**
     * Allow properties whose names start with a prefix in the set.
     * @param prefix the prefix to use.
     */
    public void appendPrefix(String prefix) {
        PropertyRef r = new PropertyRef();
        r.setPrefix(prefix);
        addPropertyref(r);
    }

    /**
     * Allow builtin (all, system or commandline) properties in the set.
     * @param b the type of builtin properties.
     */
    public void appendBuiltin(BuiltinPropertySetName b) {
        PropertyRef r = new PropertyRef();
        r.setBuiltin(b);
        addPropertyref(r);
    }

    /**
     * Set a mapper to change property names.
     * @param type mapper type.
     * @param from source pattern.
     * @param to output pattern.
     */
    public void setMapper(String type, String from, String to) {
        Mapper m = createMapper();
        Mapper.MapperType mapperType = new Mapper.MapperType();
        mapperType.setValue(type);
        m.setType(mapperType);
        m.setFrom(from);
        m.setTo(to);
    }

    /**
     * Add a property reference (nested element) to the references to be used.
     * @param ref a property reference.
     */
    public void addPropertyref(PropertyRef ref) {
        assertNotReference();
        ptyRefs.addElement(ref);
    }

    /**
     * Add another property set to this set.
     * @param ref another property set.
     */
    public void addPropertyset(PropertySet ref) {
        assertNotReference();
        setRefs.addElement(ref);
    }

    /**
     * Create a mapper to map the property names.
     * @return a mapper to be configured.
     */
    public Mapper createMapper() {
        assertNotReference();
        if (mapper != null) {
            throw new BuildException("Too many <mapper>s!");
        }
        mapper = new Mapper(getProject());
        return mapper;
    }

    /**
     * Add a nested FileNameMapper.
     * @param fileNameMapper the mapper to add.
     * @since Ant 1.6.3
     */
    public void add(FileNameMapper fileNameMapper) {
        createMapper().add(fileNameMapper);
    }

    /**
     * Set whether to reevaluate the set everytime the set is used.
     * Default is true.
     *
     * @param dynamic if true, reevaluate the property set each time
     *                the set is used. if false cache the property set
     *                the first time and use the cached set on subsequent
     *                occasions.
     */
    public void setDynamic(boolean dynamic) {
        assertNotReference();
        this.dynamic = dynamic;
    }

    /**
     * Set whether to negate results.
     * If "true", all properties not selected by nested elements will be returned.
     *  Default is "false".
     * @param negate if true, negate the selection criteria.
     */
    public void setNegate(boolean negate) {
        assertNotReference();
        this.negate = negate;
    }

    /**
     * Get the dynamic attribute.
     * @return true if the property set is to be evalulated each time it is used.
     */
    public boolean getDynamic() {
        return isReference() ? getRef().dynamic : dynamic;
    }

    /**
     * Get the mapper attribute.
     * @return the mapper attribute.
     */
    public Mapper getMapper() {
        return isReference() ? getRef().mapper : mapper;
    }

    /**
     * Convert the system properties to a hashtable.
     * Use propertynames to get the list of properties (including
     * default ones).
     */
    private Hashtable getAllSystemProperties() {
        Hashtable ret = new Hashtable();
        for (Enumeration e = System.getProperties().propertyNames();
             e.hasMoreElements();) {
            String name = (String) e.nextElement();
            ret.put(name, System.getProperties().getProperty(name));
        }
        return ret;
    }

    /**
     * This is the operation to get the existing or recalculated properties.
     * @return the properties for this propertyset.
     */
    public Properties getProperties() {
        if (isReference()) {
            return getRef().getProperties();
        }
        Set names = null;
        Project prj = getProject();
        Hashtable props =
            prj == null ? getAllSystemProperties() : prj.getProperties();

        //quick & dirty, to make nested mapped p-sets work:
        for (Enumeration e = setRefs.elements(); e.hasMoreElements();) {
            PropertySet set = (PropertySet) e.nextElement();
            props.putAll(set.getProperties());
        }

        if (getDynamic() || cachedNames == null) {
            names = new HashSet();
            addPropertyNames(names, props);
            // Add this PropertySet's nested PropertySets' property names.
            for (Enumeration e = setRefs.elements(); e.hasMoreElements();) {
                PropertySet set = (PropertySet) e.nextElement();
                names.addAll(set.getProperties().keySet());
            }
            if (negate) {
                //make a copy...
                HashSet complement = new HashSet(props.keySet());
                complement.removeAll(names);
                names = complement;
            }
            if (!getDynamic()) {
                cachedNames = names;
            }
        } else {
            names = cachedNames;
        }
        FileNameMapper m = null;
        Mapper myMapper = getMapper();
        if (myMapper != null) {
            m = myMapper.getImplementation();
        }
        Properties properties = new Properties();
        //iterate through the names, get the matching values
        for (Iterator iter = names.iterator(); iter.hasNext();) {
            String name = (String) iter.next();
            String value = (String) props.get(name);
            if (value != null) {
                // may be null if a system property has been added
                // after the project instance has been initialized
                if (m != null) {
                    //map the names
                    String[] newname = m.mapFileName(name);
                    if (newname != null) {
                        name = newname[0];
                    }
                }
                properties.setProperty(name, value);
            }
        }
        return properties;
    }

    /**
     * @param  names the output Set to fill with the property names
     *         matching this PropertySet selection criteria.
     * @param  properties the current Project properties, passed in to
     *         avoid needless duplication of the Hashtable during recursion.
     */
    private void addPropertyNames(Set names, Hashtable properties) {
        // Add this PropertySet's property names.
        for (Enumeration e = ptyRefs.elements(); e.hasMoreElements();) {
            PropertyRef r = (PropertyRef) e.nextElement();
            if (r.name != null) {
                if (properties.get(r.name) != null) {
                    names.add(r.name);
                }
            } else if (r.prefix != null) {
                for (Enumeration p = properties.keys(); p.hasMoreElements();) {
                    String name = (String) p.nextElement();
                    if (name.startsWith(r.prefix)) {
                        names.add(name);
                    }
                }
            } else if (r.regex != null) {
                RegexpMatcherFactory matchMaker = new RegexpMatcherFactory();
                RegexpMatcher matcher = matchMaker.newRegexpMatcher();
                matcher.setPattern(r.regex);
                for (Enumeration p = properties.keys(); p.hasMoreElements();) {
                    String name = (String) p.nextElement();
                    if (matcher.matches(name)) {
                        names.add(name);
                    }
                }
            } else if (r.builtin != null) {

                if (r.builtin.equals(BuiltinPropertySetName.ALL)) {
                    names.addAll(properties.keySet());
                } else if (r.builtin.equals(BuiltinPropertySetName.SYSTEM)) {
                    names.addAll(System.getProperties().keySet());
                } else if (r.builtin.equals(BuiltinPropertySetName
                                              .COMMANDLINE)) {
                    names.addAll(getProject().getUserProperties().keySet());
                } else {
                    throw new BuildException("Impossible: Invalid builtin "
                                             + "attribute!");
                }
            } else {
                throw new BuildException("Impossible: Invalid PropertyRef!");
            }
        }
    }

    /**
     * Performs the check for circular references and returns the
     * referenced PropertySet.
     * @return the referenced PropertySet.
     */
    protected PropertySet getRef() {
        return (PropertySet) getCheckedRef(PropertySet.class, "propertyset");
    }

    /**
     * Sets the value of the refid attribute.
     *
     * @param  r the reference this datatype should point to.
     * @throws BuildException if another attribute was set, since
     *         refid and all other attributes are mutually exclusive.
     */
    public final void setRefid(Reference r) {
        if (!noAttributeSet) {
            throw tooManyAttributes();
        }
        super.setRefid(r);
    }

    /**
     * Ensures this data type is not a reference.
     *
     * <p>Calling this method as the first line of every bean method of
     * this data type (setXyz, addXyz, createXyz) ensure proper handling
     * of the refid attribute.</p>
     *
     * @throws BuildException if the refid attribute was already set, since
     *         refid and all other attributes are mutually exclusive.
     */
    protected final void assertNotReference() {
        if (isReference()) {
            throw tooManyAttributes();
        }
        noAttributeSet = false;
    }

    /**
     * Flag which tracks whether any attribute has been set; used by
     * {@link #assertNotReference()} and {@link #setRefid(Reference)}.
     */
    private boolean noAttributeSet = true;

    /**
     * Used for propertyref's builtin attribute.
     */
    public static class BuiltinPropertySetName extends EnumeratedAttribute {
        static final String ALL = "all";
        static final String SYSTEM = "system";
        static final String COMMANDLINE = "commandline";
        /** {@inheritDoc}. */
        public String[] getValues() {
            return new String[] {ALL, SYSTEM, COMMANDLINE};
        }
    }

    /**
     * A debug toString.
     * This gets a comma separated list of key=value pairs for
     * the properties in the set.
     * The output order is sorted according to the keys' <i>natural order.
     * @return a string rep of this object.
     */
    public String toString() {
        StringBuffer b = new StringBuffer();
        TreeMap sorted = new TreeMap(getProperties());
        for (Iterator i = sorted.entrySet().iterator(); i.hasNext();) {
            Map.Entry e = (Map.Entry) i.next();
            if (b.length() != 0) {
                b.append(", ");
            }
            b.append(e.getKey().toString());
            b.append("=");
            b.append(e.getValue().toString());
        }
        return b.toString();
    }

    /**
     * Fulfill the ResourceCollection interface.
     * @return an Iterator of Resources.
     * @since Ant 1.7
     */
    public Iterator iterator() {
        final Enumeration e = getProperties().propertyNames();
        return new Iterator() {
            public boolean hasNext() {
                return e.hasMoreElements();
            }
            public Object next() {
                return new PropertyResource(getProject(), (String) e.nextElement());
            }
            public void remove() {
                throw new UnsupportedOperationException();
            }
        };
    }

    /**
     * Fulfill the ResourceCollection contract.
     * @return the size of this ResourceCollection.
     */
    public int size() {
        return isReference() ? getRef().size() : getProperties().size();
    }

    /**
     * Fulfill the ResourceCollection contract.
     * @return whether this is a filesystem-only resource collection.
     */
    public boolean isFilesystemOnly() {
        return isReference() && getRef().isFilesystemOnly();
    }

}