Ant example source code file (Location.java)

This example Ant source code file (Location.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

file_utils, file_utils, fileutils, io, location, location, sax, serializable, string, string, stringbuffer, stringbuffer, unknown_location

The Location.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;

import java.io.Serializable;
import org.apache.tools.ant.util.FileUtils;
import org.xml.sax.Locator;

/**
 * Stores the location of a piece of text within a file (file name,
 * line number and column number). Note that the column number is
 * currently ignored.
 *
 */
public class Location implements Serializable {

    /** Name of the file. */
    private String fileName;
    /** Line number within the file. */
    private int lineNumber;
    /** Column number within the file. */
    private int columnNumber;

    /** Location to use when one is needed but no information is available */
    public static final Location UNKNOWN_LOCATION = new Location();

    private static final FileUtils FILE_UTILS = FileUtils.getFileUtils();

    /**
     * Creates an "unknown" location.
     */
    private Location() {
        this(null, 0, 0);
    }

    /**
     * Creates a location consisting of a file name but no line number or
     * column number.
     *
     * @param fileName The name of the file. May be <code>null,
     *                 in which case the location is equivalent to
     *                 {@link #UNKNOWN_LOCATION UNKNOWN_LOCATION}.
     */
    public Location(String fileName) {
        this(fileName, 0, 0);
    }

    /**
     * Creates a location from the SAX locator using the system ID as
     * the filename.
     *
     * @param loc Must not be <code>null.
     *
     * @since Ant 1.6
     */
    public Location(Locator loc) {
        this(loc.getSystemId(), loc.getLineNumber(), loc.getColumnNumber());
    }

    /**
     * Creates a location consisting of a file name, line number and
     * column number.
     *
     * @param fileName The name of the file. May be <code>null,
     *                 in which case the location is equivalent to
     *                 {@link #UNKNOWN_LOCATION UNKNOWN_LOCATION}.
     *
     * @param lineNumber Line number within the file. Use 0 for unknown
     *                   positions within a file.
     * @param columnNumber Column number within the line.
     */
    public Location(String fileName, int lineNumber, int columnNumber) {
        if (fileName != null && fileName.startsWith("file:")) {
            this.fileName = FILE_UTILS.fromURI(fileName);
        } else {
            this.fileName = fileName;
        }
        this.lineNumber = lineNumber;
        this.columnNumber = columnNumber;
    }

    /**
     * @return the filename portion of the location
     * @since Ant 1.6
     */
    public String getFileName() {
        return fileName;
    }

    /**
     * @return the line number
     * @since Ant 1.6
     */
    public int getLineNumber() {
        return lineNumber;
    }

    /**
     * @return the column number
     * @since Ant 1.7
     */
    public int getColumnNumber() {
        return columnNumber;
    }

    /**
     * Returns the file name, line number, a colon and a trailing space.
     * An error message can be appended easily. For unknown locations, an
     * empty string is returned.
     *
     * @return a String of the form <code>"fileName:lineNumber: "
     *         if both file name and line number are known,
     *         <code>"fileName: " if only the file name is known,
     *         and the empty string for unknown locations.
     */
    public String toString() {
        StringBuffer buf = new StringBuffer();

        if (fileName != null) {
            buf.append(fileName);

            if (lineNumber != 0) {
                buf.append(":");
                buf.append(lineNumber);
            }

            buf.append(": ");
        }

        return buf.toString();
    }

    /**
     * Equality operation.
     * @param other the object to compare to.
     * @return true if the other object contains the same information
     *              as this object.
     * @since Ant 1.6.3
     */
    public boolean equals(Object other) {
        if (this == other) {
            return true;
        }
        if (other == null) {
            return false;
        }
        if (!(other.getClass() == getClass())) {
            return false;
        }
        return toString().equals(other.toString());
    }

    /**
     * Hash operation.
     * @return a hash code value for this location.
     * @since Ant 1.6.3
     */
    public int hashCode() {
        return toString().hashCode();
    }
}