Ant example source code file (Resource.java)

This example Ant source code file (Resource.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

clonenotsupportedexception, comparable, io, ioexception, long, long, math, object, resource, resource, string, string, unknown_datetime, unknown_size, unknown_size, unsupportedoperationexception, util

The Resource.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.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.math.BigInteger;
import java.util.Iterator;
import java.util.NoSuchElementException;

/**
 * Describes a "File-like" resource (File, ZipEntry, etc.).
 *
 * This class is meant to be used by classes needing to record path
 * and date/time information about a file, a zip entry or some similar
 * resource (URL, archive in a version control repository, ...).
 *
 * @since Ant 1.5.2
 * @see org.apache.tools.ant.types.resources.Touchable
 */
public class Resource extends DataType
    implements Cloneable, Comparable, ResourceCollection {

    /** Constant unknown size */
    public static final long UNKNOWN_SIZE = -1;

    /** Constant unknown datetime for getLastModified */
    public static final long UNKNOWN_DATETIME = 0L;

    /** Magic number */
    protected static final int MAGIC = getMagicNumber("Resource".getBytes());

    private static final int NULL_NAME = getMagicNumber("null name".getBytes());

    /**
     * Create a "magic number" for use in hashCode calculations.
     * @param seed byte[] to seed with.
     * @return a magic number as int.
     */
    protected static int getMagicNumber(byte[] seed) {
        return new BigInteger(seed).intValue();
    }

    private String name = null;
    private Boolean exists = null;
    private Long lastmodified = null;
    private Boolean directory = null;
    private Long size = null;

    /**
     * Default constructor.
     */
    public Resource() {
    }

    /**
     * Only sets the name.
     *
     * <p>This is a dummy, used for not existing resources.

     *
     * @param name relative path of the resource.  Expects
     * "/" to be used as the directory separator.
     */
    public Resource(String name) {
        this(name, false, 0, false);
    }

    /**
     * Sets the name, lastmodified flag, and exists flag.
     *
     * @param name relative path of the resource.  Expects
     * "/" to be used as the directory separator.
     * @param exists if true, this resource exists.
     * @param lastmodified the last modification time of this resource.
     */
    public Resource(String name, boolean exists, long lastmodified) {
        this(name, exists, lastmodified, false);
    }

    /**
     * Sets the name, lastmodified flag, exists flag, and directory flag.
     *
     * @param name relative path of the resource.  Expects
     * "/" to be used as the directory separator.
     * @param exists if true the resource exists
     * @param lastmodified the last modification time of the resource
     * @param directory    if true, this resource is a directory
     */
    public Resource(String name, boolean exists, long lastmodified,
                    boolean directory) {
        this(name, exists, lastmodified, directory, UNKNOWN_SIZE);
    }

    /**
     * Sets the name, lastmodified flag, exists flag, directory flag, and size.
     *
     * @param name relative path of the resource.  Expects
     * "/" to be used as the directory separator.
     * @param exists if true the resource exists
     * @param lastmodified the last modification time of the resource
     * @param directory    if true, this resource is a directory
     * @param size the size of this resource.
     */
    public Resource(String name, boolean exists, long lastmodified,
                    boolean directory, long size) {
        this.name = name;
        setName(name);
        setExists(exists);
        setLastModified(lastmodified);
        setDirectory(directory);
        setSize(size);
    }

    /**
     * Name attribute will contain the path of a file relative to the
     * root directory of its fileset or the recorded path of a zip
     * entry.
     *
     * <p>example for a file with fullpath /var/opt/adm/resource.txt
     * in a file set with root dir /var/opt it will be
     * adm/resource.txt.</p>
     *
     * <p>"/" will be used as the directory separator.

     * @return the name of this resource.
     */
    public String getName() {
        return isReference() ? ((Resource) getCheckedRef()).getName() : name;
    }

    /**
     * Set the name of this Resource.
     * @param name relative path of the resource.  Expects
     * "/" to be used as the directory separator.
     */
    public void setName(String name) {
        checkAttributesAllowed();
        this.name = name;
    }

    /**
     * The exists attribute tells whether a file exists.
     * @return true if this resource exists.
     */
    public boolean isExists() {
        if (isReference()) {
            return ((Resource) getCheckedRef()).isExists();
        }
        //default true:
        return exists == null || exists.booleanValue();
    }

    /**
     * Set the exists attribute.
     * @param exists if true, this resource exists.
     */
    public void setExists(boolean exists) {
        checkAttributesAllowed();
        this.exists = exists ? Boolean.TRUE : Boolean.FALSE;
    }

    /**
     * Tells the modification time in milliseconds since 01.01.1970 .
     *
     * @return 0 if the resource does not exist to mirror the behavior
     * of {@link java.io.File File}.
     */
    public long getLastModified() {
        if (isReference()) {
            return ((Resource) getCheckedRef()).getLastModified();
        }
        if (!isExists() || lastmodified == null) {
            return UNKNOWN_DATETIME;
        }
        long result = lastmodified.longValue();
        return result < UNKNOWN_DATETIME ? UNKNOWN_DATETIME : result;
    }

    /**
     * Set the last modification attribute.
     * @param lastmodified the modification time in milliseconds since 01.01.1970.
     */
    public void setLastModified(long lastmodified) {
        checkAttributesAllowed();
        this.lastmodified = new Long(lastmodified);
    }

    /**
     * Tells if the resource is a directory.
     * @return boolean flag indicating if the resource is a directory.
     */
    public boolean isDirectory() {
        if (isReference()) {
            return ((Resource) getCheckedRef()).isDirectory();
        }
        //default false:
        return directory != null && directory.booleanValue();
    }

    /**
     * Set the directory attribute.
     * @param directory if true, this resource is a directory.
     */
    public void setDirectory(boolean directory) {
        checkAttributesAllowed();
        this.directory = directory ? Boolean.TRUE : Boolean.FALSE;
    }

    /**
     * Set the size of this Resource.
     * @param size the size, as a long.
     * @since Ant 1.6.3
     */
    public void setSize(long size) {
        checkAttributesAllowed();
        this.size = new Long(size > UNKNOWN_SIZE ? size : UNKNOWN_SIZE);
    }

    /**
     * Get the size of this Resource.
     * @return the size, as a long, 0 if the Resource does not exist (for
     *         compatibility with java.io.File), or UNKNOWN_SIZE if not known.
     * @since Ant 1.6.3
     */
    public long getSize() {
        if (isReference()) {
            return ((Resource) getCheckedRef()).getSize();
        }
        return isExists()
            ? (size != null ? size.longValue() : UNKNOWN_SIZE)
            : 0L;
    }

    /**
     * Clone this Resource.
     * @return copy of this.
     */
    public Object clone() {
        try {
            return super.clone();
        } catch (CloneNotSupportedException e) {
            throw new UnsupportedOperationException(
                    "CloneNotSupportedException for a Resource caught. "
                    + "Derived classes must support cloning.");
        }
    }

    /**
     * Delegates to a comparison of names.
     * @param other the object to compare to.
     * @return a negative integer, zero, or a positive integer as this Resource
     *         is less than, equal to, or greater than the specified Resource.
     * @since Ant 1.6
     */
    public int compareTo(Object other) {
        if (isReference()) {
            return ((Comparable) getCheckedRef()).compareTo(other);
        }
        if (!(other instanceof Resource)) {
            throw new IllegalArgumentException(
                "Can only be compared with Resources");
        }
        return toString().compareTo(other.toString());
    }

    /**
     * Implement basic Resource equality.
     * @param other the object to check against.
     * @return true if the specified Object is equal to this Resource.
     * @since Ant 1.7
     */
    public boolean equals(Object other) {
        if (isReference()) {
            return getCheckedRef().equals(other);
        }
        return other.getClass().equals(getClass()) && compareTo(other) == 0;
    }

    /**
     * Get the hash code for this Resource.
     * @return hash code as int.
     * @since Ant 1.7
     */
    public int hashCode() {
        if (isReference()) {
            return getCheckedRef().hashCode();
        }
        String name = getName();
        return MAGIC * (name == null ? NULL_NAME : name.hashCode());
    }

    /**
     * Get an InputStream for the Resource.
     * @return an InputStream containing this Resource's content.
     * @throws IOException if unable to provide the content of this
     *         Resource as a stream.
     * @throws UnsupportedOperationException if InputStreams are not
     *         supported for this Resource type.
     * @since Ant 1.7
     */
    public InputStream getInputStream() throws IOException {
        if (isReference()) {
            return ((Resource) getCheckedRef()).getInputStream();
        }
        throw new UnsupportedOperationException();
    }

    /**
     * Get an OutputStream for the Resource.
     * @return an OutputStream to which content can be written.
     * @throws IOException if unable to provide the content of this
     *         Resource as a stream.
     * @throws UnsupportedOperationException if OutputStreams are not
     *         supported for this Resource type.
     * @since Ant 1.7
     */
    public OutputStream getOutputStream() throws IOException {
        if (isReference()) {
            return ((Resource) getCheckedRef()).getOutputStream();
        }
        throw new UnsupportedOperationException();
    }

    /**
     * Fulfill the ResourceCollection contract.
     * @return an Iterator of Resources.
     * @since Ant 1.7
     */
    public Iterator iterator() {
        return isReference() ? ((Resource) getCheckedRef()).iterator()
            : new Iterator() {
            private boolean done = false;
            public boolean hasNext() {
                return !done;
            }
            public Object next() {
                if (done) {
                    throw new NoSuchElementException();
                }
                done = true;
                return Resource.this;
            }
            public void remove() {
                throw new UnsupportedOperationException();
            }
        };
    }

    /**
     * Fulfill the ResourceCollection contract.
     * @return the size of this ResourceCollection.
     * @since Ant 1.7
     */
    public int size() {
        return isReference() ? ((Resource) getCheckedRef()).size() : 1;
    }

    /**
     * Fulfill the ResourceCollection contract.
     * @return whether this Resource is a FileResource.
     * @since Ant 1.7
     */
    public boolean isFilesystemOnly() {
        //default false:
        return isReference() && ((Resource) getCheckedRef()).isFilesystemOnly();
    }

    /**
     * Get the string representation of this Resource.
     * @return this Resource formatted as a String.
     * @since Ant 1.7
     */
    public String toString() {
        if (isReference()) {
            return getCheckedRef().toString();
        }
        String n = getName();
        return n == null ? "(anonymous)" : n;
    }

    /**
     * Get a long String representation of this Resource.
     * This typically should be the value of <code>toString()
     * prefixed by a type description.
     * @return this Resource formatted as a long String.
     * @since Ant 1.7
     */
    public final String toLongString() {
        return isReference() ? ((Resource) getCheckedRef()).toLongString()
            : getDataTypeName() + " \"" + toString() + '"';
    }

    /**
     * Overrides the base version.
     * @param r the Reference to set.
     */
    public void setRefid(Reference r) {
        if (name != null
            || exists != null
            || lastmodified != null
            || directory != null
            || size != null) {
            throw tooManyAttributes();
        }
        super.setRefid(r);
    }

}