Add utility object to help display library specifications and extensions

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@272508 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/taskdefs/optional/extension/LibraryDisplayer.java

@@ -0,0 +1,234 @@
+/*
+ * 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.taskdefs.optional.extension;
+
+import java.io.File;
+import java.io.IOException;
+import java.text.ParseException;
+import java.util.jar.JarFile;
+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.
+ *
+ * @author <a href="mailto:peter@apache.org">Peter Donald</a>
+ * @version $Revision$ $Date$
+ */
+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 = 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() );
+    }
+
+    /**
+     * retrieve manifest for specified file.
+     *
+     * @param file the file
+     * @return the manifest
+     * @throws BuildException if errror occurs (file not exist,
+     *         file not a jar, manifest not exist in file)
+     */
+    private Manifest getManifest( final File file )
+        throws BuildException
+    {
+        try
+        {
+            final JarFile jarFile = new JarFile( file );
+            return jarFile.getManifest();
+        }
+        catch( final IOException ioe )
+        {
+            throw new BuildException( ioe.getMessage(), ioe );
+        }
+    }
+}