Ant example source code file (LibraryDisplayer.java)

This example Ant source code file (LibraryDisplayer.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, buildexception, extension, extension, file, file, io, jar, librarydisplayer, manifest, parseexception, sections, specification, specification, string, stringbuffer, text

The LibraryDisplayer.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.taskdefs.optional.extension;

import java.io.File;
import java.text.ParseException;
import java.util.jar.Manifest;
import org.apache.tools.ant.BuildException;

/**
 * Utility class to output the information in a jar relating
 * to "Optional Packages" (formely known as "Extensions")
 * and Package Specifications.
 *
 */
class LibraryDisplayer {
    /**
     * Display the extensions and specifications contained
     * within specified file.
     *
     * @param file the file
     * @throws BuildException if fail to read file
     */
    void displayLibrary(final File file)
        throws BuildException {
        final Manifest manifest = ExtensionUtil.getManifest(file);
        displayLibrary(file, manifest);
    }

    /**
     * Display the extensions and specifications contained
     * within specified file.
     *
     * @param file the file to use while reporting
     * @param manifest the manifest of file
     * @throws BuildException if fail to read file
     */
    void displayLibrary(final File file,
                         final Manifest manifest)
        throws BuildException {
        final Extension[] available = Extension.getAvailable(manifest);
        final Extension[] required = Extension.getRequired(manifest);
        final Extension[] options = Extension.getOptions(manifest);
        final Specification[] specifications = getSpecifications(manifest);

        if (0 == available.length && 0 == required.length && 0 == options.length
            && 0 == specifications.length) {
            return;
        }

        final String message = "File: " + file;
        final int size = message.length();
        printLine(size);
        System.out.println(message);
        printLine(size);
        if (0 != available.length) {
            System.out.println("Extensions Supported By Library:");
            for (int i = 0; i < available.length; i++) {
                final Extension extension = available[ i ];
                System.out.println(extension.toString());
            }
        }

        if (0 != required.length) {
            System.out.println("Extensions Required By Library:");
            for (int i = 0; i < required.length; i++) {
                final Extension extension = required[ i ];
                System.out.println(extension.toString());
            }
        }

        if (0 != options.length) {
            System.out.println("Extensions that will be used by Library if present:");
            for (int i = 0; i < options.length; i++) {
                final Extension extension = options[ i ];
                System.out.println(extension.toString());
            }
        }

        if (0 != specifications.length) {
            System.out.println("Specifications Supported By Library:");
            for (int i = 0; i < specifications.length; i++) {
                final Specification specification = specifications[ i ];
                displaySpecification(specification);
            }
        }
    }

    /**
     * Print out a line of '-'s equal to specified size.
     *
     * @param size the number of dashes to printout
     */
    private void printLine(final int size) {
        for (int i = 0; i < size; i++) {
            System.out.print("-");
        }
        System.out.println();
    }

    /**
     * Get specifications from manifest.
     *
     * @param manifest the manifest
     * @return the specifications or null if none
     * @throws BuildException if malformed specification sections
     */
    private Specification[] getSpecifications(final Manifest manifest)
        throws BuildException {
        try {
            return Specification.getSpecifications(manifest);
        } catch (final ParseException pe) {
            throw new BuildException(pe.getMessage(), pe);
        }
    }

    /**
     * Print out specification details.
     *
     * @param specification the specification
     */
    private void displaySpecification(final Specification specification) {
        final String[] sections = specification.getSections();
        if (null != sections) {
            final StringBuffer sb = new StringBuffer("Sections: ");
            for (int i = 0; i < sections.length; i++) {
                sb.append(" ");
                sb.append(sections[ i ]);
            }
            System.out.println(sb);
        }
        System.out.println(specification.toString());
    }
}