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Posted to cvs@avalon.apache.org by do...@apache.org on 2002/04/01 12:32:40 UTC

cvs commit: jakarta-avalon-excalibur/extension/src/java/org/apache/avalon/excalibur/extension Specification.java

donaldp     02/04/01 02:32:40

  Added:       extension/src/java/org/apache/avalon/excalibur/extension
                        Specification.java
  Log:
  Start to implement a PackageSpecification  parsing/reading mechanism similar to Extension parsing/reading mechanism
  
  Revision  Changes    Path
  1.1                  jakarta-avalon-excalibur/extension/src/java/org/apache/avalon/excalibur/extension/Specification.java
  
  Index: Specification.java
  ===================================================================
  /*
   * Copyright (C) The Apache Software Foundation. All rights reserved.
   *
   * This software is published under the terms of the Apache Software License
   * version 1.1, a copy of which has been included with this distribution in
   * the LICENSE.txt file.
   */
  package org.apache.avalon.excalibur.extension;
  
  import java.text.ParseException;
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.Map;
  import java.util.jar.Attributes;
  import java.util.jar.Manifest;
  
  /**
   * <p>Utility class that represents either an available "Optional Package"
   * (formerly known as "Standard Extension") as described in the manifest
   * of a JAR file, or the requirement for such an optional package.</p>
   *
   * <p>For more information about optional packages, see the document
   * <em>Optional Package Versioning</em> in the documentation bundle for your
   * Java2 Standard Edition package, in file
   * <code>guide/extensions/versioning.html</code>.</p>
   *
   * @author <a href="mailto:peter@apache.org">Peter Donald</a>
   * @version $Revision: 1.1 $ $Date: 2002/04/01 10:32:40 $
   */
  public final class Specification
  {
      /**
       * Manifest Attribute Name object for SPECIFICATION_TITLE.
       * @see Attributes.Name#SPECIFICATION_TITLE
       */
      public static final Attributes.Name SPECIFICATION_TITLE = Attributes.Name.SPECIFICATION_TITLE;
  
      /**
       * Manifest Attribute Name object for SPECIFICATION_VERSION.
       * @see Attributes.Name#SPECIFICATION_VERSION
       */
      public static final Attributes.Name SPECIFICATION_VERSION = Attributes.Name.SPECIFICATION_VERSION;
  
      /**
       * Manifest Attribute Name object for SPECIFICATION_VENDOR.
       * @see Attributes.Name#SPECIFICATION_VENDOR
       */
      public static final Attributes.Name SPECIFICATION_VENDOR = Attributes.Name.SPECIFICATION_VENDOR;
  
      /**
       * Manifest Attribute Name object for IMPLEMENTATION_TITLE.
       * @see Attributes.Name#IMPLEMENTATION_TITLE
       */
      public static final Attributes.Name IMPLEMENTATION_TITLE = Attributes.Name.IMPLEMENTATION_TITLE;
  
      /**
       * Manifest Attribute Name object for IMPLEMENTATION_VERSION.
       * @see Attributes.Name#IMPLEMENTATION_VERSION
       */
      public static final Attributes.Name IMPLEMENTATION_VERSION = Attributes.Name.IMPLEMENTATION_VERSION;
  
      /**
       * Manifest Attribute Name object for IMPLEMENTATION_VENDOR.
       * @see Attributes.Name#IMPLEMENTATION_VENDOR
       */
      public static final Attributes.Name IMPLEMENTATION_VENDOR = Attributes.Name.IMPLEMENTATION_VENDOR;
  
      /**
       * Enum indicating that extension is compatible with other Package
       * Specification.
       */
      public static final Compatability COMPATIBLE =
          new Compatability( "COMPATIBLE" );
  
      /**
       * Enum indicating that extension requires an upgrade
       * of specification to be compatible with other Package Specification.
       */
      public static final Compatability REQUIRE_SPECIFICATION_UPGRADE =
          new Compatability( "REQUIRE_SPECIFICATION_UPGRADE" );
  
      /**
       * Enum indicating that extension requires a vendor
       * switch to be compatible with other Package Specification.
       */
      public static final Compatability REQUIRE_VENDOR_SWITCH =
          new Compatability( "REQUIRE_VENDOR_SWITCH" );
  
      /**
       * Enum indicating that extension requires an upgrade
       * of implementation to be compatible with other Package Specification.
       */
      public static final Compatability REQUIRE_IMPLEMENTATION_CHANGE =
          new Compatability( "REQUIRE_IMPLEMENTATION_CHANGE" );
  
      /**
       * Enum indicating that extension is incompatible with
       * other Package Specification in ways other than other enums
       * indicate). ie For example the other Package Specification
       * may have a different ID.
       */
      public static final Compatability INCOMPATIBLE =
          new Compatability( "INCOMPATIBLE" );
  
      /**
       * The name of the Package Specification.
       */
      private String m_specificationTitle;
  
      /**
       * The version number (dotted decimal notation) of the specification
       * to which this optional package conforms.
       */
      private DeweyDecimal m_specificationVersion;
  
      /**
       * The name of the company or organization that originated the
       * specification to which this specification conforms.
       */
      private String m_specificationVendor;
  
      /**
       * The title of implementation.
       */
      private String m_implementationTitle;
  
      /**
       * The name of the company or organization that produced this
       * implementation of this specification.
       */
      private String m_implementationVendor;
  
      /**
       * The version string for implementation. The version string is
       * opaque.
       */
      private String m_implementationVersion;
  
      /**
       * Return an array of <code>Package Specification</code> objects.
       * If there are no such optional packages, a zero-length array is returned.
       *
       * @param manifest Manifest to be parsed
       * @return the Package Specifications extensions in specified manifest
       */
      public static Specification[] getPackageSpecifications( final Manifest manifest )
          throws ParseException
      {
          if( null == manifest )
          {
              return new Specification[ 0 ];
          }
  
          final ArrayList results = new ArrayList();
  
          final Map entries = manifest.getEntries();
          final Iterator keys = entries.keySet().iterator();
          while( keys.hasNext() )
          {
              final String key = (String)keys.next();
              final Attributes attributes = (Attributes)entries.get( key );
              final Specification specification = getSpecification( attributes );
              if( null != specification )
              {
                  results.add( specification );
              }
          }
  
          return (Specification[])results.toArray( new Specification[ 0 ] );
      }
  
      /**
       * The constructor to create Package Specification object.
       * Note that every component is allowed to be specified
       * but only the specificationTitle is mandatory.
       *
       * @param specificationTitle the name of specification.
       * @param specificationVersion the specification Version.
       * @param specificationVendor the specification Vendor.
       * @param implementationTitle the title of implementation.
       * @param implementationVersion the implementation Version.
       * @param implementationVendor the implementation Vendor.
       */
      public Specification( final String specificationTitle,
                            final String specificationVersion,
                            final String specificationVendor,
                            final String implementationTitle,
                            final String implementationVersion,
                            final String implementationVendor )
      {
          m_specificationTitle = specificationTitle;
          m_specificationVendor = specificationVendor;
  
          if( null != specificationVersion )
          {
              try
              {
                  m_specificationVersion = new DeweyDecimal( specificationVersion );
              }
              catch( final NumberFormatException nfe )
              {
                  final String error = "Bad specification version format '" + specificationVersion +
                      "' in '" + specificationTitle + "'. (Reason: " + nfe + ")";
                  throw new IllegalArgumentException( error );
              }
          }
  
          m_implementationTitle = implementationTitle;
          m_implementationVendor = implementationVendor;
          m_implementationVersion = implementationVersion;
  
          if( null == m_specificationTitle )
          {
              throw new NullPointerException( "specificationTitle" );
          }
      }
  
      /**
       * Get the title of the specification.
       *
       * @return the title of speciication
       */
      public String getSpecificationTitle()
      {
          return m_specificationTitle;
      }
  
      /**
       * Get the vendor of the specification.
       *
       * @return the vendor of the specification.
       */
      public String getSpecificationVendor()
      {
          return m_specificationVendor;
      }
  
      /**
       * Get the title of the specification.
       *
       * @return the title of the specification.
       */
      public String getImplementationTitle()
      {
          return m_implementationTitle;
      }
  
      /**
       * Get the version of the specification.
       *
       * @return the version of the specification.
       */
      public DeweyDecimal getSpecificationVersion()
      {
          return m_specificationVersion;
      }
  
      /**
       * Get the vendor of the extensions implementation.
       *
       * @return the vendor of the extensions implementation.
       */
      public String getImplementationVendor()
      {
          return m_implementationVendor;
      }
  
      /**
       * Get the version of the implementation.
       *
       * @return the version of the implementation.
       */
      public String getImplementationVersion()
      {
          return m_implementationVersion;
      }
  
      /**
       * Return a Compatibility enum indicating the relationship of this
       * <code>Package Specification</code> with the specified <code>Extension</code>.
       *
       * @param other the other specification
       * @return the enum indicating the compatability (or lack thereof)
       *         of specifed Package Specification
       */
      public Compatability getCompatibilityWith( final Specification other )
      {
          // Specification Name must match
          if( !m_specificationTitle.equals( other.getSpecificationTitle() ) )
          {
              return INCOMPATIBLE;
          }
  
          // Available specification version must be >= required
          final DeweyDecimal specificationVersion = other.getSpecificationVersion();
          if( null != specificationVersion )
          {
              if( null == m_specificationVersion ||
                  !isCompatible( m_specificationVersion, specificationVersion ) )
              {
                  return REQUIRE_SPECIFICATION_UPGRADE;
              }
          }
  
          // Implementation Vendor ID must match
          final String implementationVendor = other.getImplementationVendor();
          if( null != implementationVendor )
          {
              if( null == m_implementationVendor ||
                  !m_implementationVendor.equals( implementationVendor ) )
              {
                  return REQUIRE_VENDOR_SWITCH;
              }
          }
  
          // Implementation version must be >= required
          final String implementationVersion = other.getImplementationVersion();
          if( null != implementationVersion )
          {
              if( null == m_implementationVersion ||
                  !m_implementationVersion.equals( implementationVersion ) )
              {
                  return REQUIRE_IMPLEMENTATION_CHANGE;
              }
          }
  
          // This available optional package satisfies the requirements
          return COMPATIBLE;
      }
  
      /**
       * Return <code>true</code> if the specified <code>package</code>
       * is satisfied by this <code>Specification</code>. Otherwise, return
       * <code>false</code>.
       *
       * @param other the specification
       * @return true if the specification is compatible with this specification
       */
      public boolean isCompatibleWith( final Specification other )
      {
          return ( COMPATIBLE == getCompatibilityWith( other ) );
      }
  
      /**
       * Return a String representation of this object.
       *
       * @return string representation of object.
       */
      public String toString()
      {
          final String lineSeparator = System.getProperty( "line.separator" );
          final String brace = ": ";
  
          final StringBuffer sb = new StringBuffer( SPECIFICATION_TITLE.toString() );
          sb.append( brace );
          sb.append( m_specificationTitle );
          sb.append( lineSeparator );
  
          if( null != m_specificationVersion )
          {
              sb.append( SPECIFICATION_VERSION );
              sb.append( brace );
              sb.append( m_specificationVersion );
              sb.append( lineSeparator );
          }
  
          if( null != m_specificationVendor )
          {
              sb.append( SPECIFICATION_VENDOR );
              sb.append( brace );
              sb.append( m_specificationVendor );
              sb.append( lineSeparator );
          }
  
          if( null != m_implementationTitle )
          {
              sb.append( IMPLEMENTATION_TITLE );
              sb.append( brace );
              sb.append( m_implementationTitle );
              sb.append( lineSeparator );
          }
  
          if( null != m_implementationVersion )
          {
              sb.append( IMPLEMENTATION_VERSION );
              sb.append( brace );
              sb.append( m_implementationVersion );
              sb.append( lineSeparator );
          }
  
          if( null != m_implementationVendor )
          {
              sb.append( IMPLEMENTATION_VENDOR );
              sb.append( brace );
              sb.append( m_implementationVendor );
              sb.append( lineSeparator );
          }
  
          return sb.toString();
      }
  
      /**
       * Return <code>true</code> if the first version number is greater than
       * or equal to the second; otherwise return <code>false</code>.
       *
       * @param first First version number (dotted decimal)
       * @param second Second version number (dotted decimal)
       */
      private boolean isCompatible( final DeweyDecimal first, final DeweyDecimal second )
      {
          return first.isGreaterThanOrEqual( second );
      }
  
      /**
       * Trim the supplied string if the string is non-null
       *
       * @param value the string to trim or null
       * @return the trimmed string or null
       */
      private static String getTrimmedString( final String value )
      {
          if( null == value )
          {
              return null;
          }
          else
          {
              return value.trim();
          }
      }
  
      /**
       * Extract an Package Specification from Attributes.
       *
       * @param attributes Attributes to searched
       * @return the new Specification object, or null
       */
      private static Specification getSpecification( final Attributes attributes )
      throws ParseException
      {
          //WARNING: We trim the values of all the attributes because
          //Some extension declarations are badly defined (ie have spaces
          //after version or vendor)
          final String name = getTrimmedString( attributes.getValue( SPECIFICATION_TITLE ) );
          if( null == name )
          {
              return null;
          }
  
  
          final String specVendor = getTrimmedString( attributes.getValue( SPECIFICATION_VENDOR ) );
          if( null == specVendor )
          {
              throw new ParseException( "Missing " + SPECIFICATION_VENDOR, 0 );
          }
  
          final String specVersion = getTrimmedString( attributes.getValue( SPECIFICATION_VERSION ) );
          if( null == specVersion )
          {
              throw new ParseException( "Missing " + SPECIFICATION_VERSION, 0 );
          }
  
          final String impTitle = getTrimmedString( attributes.getValue( IMPLEMENTATION_TITLE ) );
          if( null == impTitle )
          {
              throw new ParseException( "Missing " + IMPLEMENTATION_TITLE, 0 );
          }
  
          final String impVersion = getTrimmedString( attributes.getValue( IMPLEMENTATION_VERSION ) );
          if( null == impVersion )
          {
              throw new ParseException( "Missing " + IMPLEMENTATION_VERSION, 0 );
          }
  
          final String impVendor = getTrimmedString( attributes.getValue( IMPLEMENTATION_VENDOR ) );
          if( null == impVendor )
          {
              throw new ParseException( "Missing " + IMPLEMENTATION_VENDOR, 0 );
          }
  
          return new Specification( name, specVersion, specVendor,
                                    impTitle, impVersion, impVendor );
      }
  }
  
  

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