import org.codehaus.plexus.interpolation.EnvarBasedValueSource; //导入依赖的package包/类
private void interpolate() throws Exception {
  Interpolator interpolator = new StringSearchInterpolator();
  interpolator.addValueSource(new MapBasedValueSource(properties));
  interpolator.addValueSource(new MapBasedValueSource(System.getProperties()));
  interpolator.addValueSource(new EnvarBasedValueSource());

  for (Entry<String, String> entry : properties.entrySet()) {
    properties.put(entry.getKey(), interpolator.interpolate(entry.getValue()));
  }
}
 

import org.codehaus.plexus.interpolation.EnvarBasedValueSource; //导入依赖的package包/类
public String interpolate(final String value, final IgnoreWarnFail onMissingProperty, final Map<String, String> properties)
                throws IOException, InterpolationException
{
    checkNotNull(value, "value is null");
    checkNotNull(properties, "properties is null");

    final Interpolator interpolator = new StringSearchInterpolator(PREFIX, POSTFIX);
    interpolator.addValueSource(new EnvarBasedValueSource());
    interpolator.addValueSource(new PropertiesBasedValueSource(System.getProperties()));

    if (model.isPresent()) {
        final Model pomModel = model.get();
        interpolator.addValueSource(new PrefixedValueSourceWrapper(new ObjectBasedValueSource(pomModel),
                                                                   SYNONYM_PREFIXES,
                                                                   true));

        interpolator.addValueSource(new PrefixedValueSourceWrapper(new PropertiesBasedValueSource(pomModel.getProperties()),
                                                                   SYNONYM_PREFIXES,
                                                                   true));
    }

    interpolator.addValueSource(new MapBasedValueSource(properties));

    final String result = interpolator.interpolate(value, new PrefixAwareRecursionInterceptor(SYNONYM_PREFIXES, true));
    final String stripped = result.replaceAll(Pattern.quote(PREFIX) + ".*?" + Pattern.quote(POSTFIX), "");
    IgnoreWarnFail.checkState(onMissingProperty, stripped.equals(result), "property");
    return stripped;
}
 

import org.codehaus.plexus.interpolation.EnvarBasedValueSource; //导入依赖的package包/类
public ProfilesRoot buildProfiles( File basedir )
    throws IOException, XmlPullParserException
{
    File profilesXml = new File( basedir, PROFILES_XML_FILE );

    ProfilesRoot profilesRoot = null;

    if ( profilesXml.exists() )
    {
        ProfilesXpp3Reader reader = new ProfilesXpp3Reader();
        Reader profileReader = null;
        try
        {
            profileReader = ReaderFactory.newXmlReader( profilesXml );

            StringWriter sWriter = new StringWriter();

            IOUtil.copy( profileReader, sWriter );

            String rawInput = sWriter.toString();

            try
            {
                RegexBasedInterpolator interpolator = new RegexBasedInterpolator();
                interpolator.addValueSource( new EnvarBasedValueSource() );

                rawInput = interpolator.interpolate( rawInput, "settings" );
            }
            catch ( Exception e )
            {
                getLogger().warn( "Failed to initialize environment variable resolver. Skipping environment "
                                      + "substitution in " + PROFILES_XML_FILE + "." );
                getLogger().debug( "Failed to initialize envar resolver. Skipping resolution.", e );
            }

            StringReader sReader = new StringReader( rawInput );

            profilesRoot = reader.read( sReader );
        }
        finally
        {
            IOUtil.close( profileReader );
        }
    }

    return profilesRoot;
}