DataDirectoryConverterLocator.java

/* (c) 2014 - 2016 Open Source Geospatial Foundation - all rights reserved
 * (c) 2001 - 2013 OpenPlans
 * This code is licensed under the GPL 2.0 license, available at the root
 * application directory.
 */
package org.geoserver.web.util;

import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.apache.wicket.IConverterLocator;
import org.apache.wicket.util.convert.IConverter;
import org.geoserver.platform.GeoServerResourceLoader;
import org.geotools.util.logging.Logging;

/**
 * Special converter locator which can resolve relative urls relative to the
 * GeoServer data directory.
 * <p>
 * This converter locator will turn URL's of the form "file:data/..." into full
 * path URL's such as "file://var/lib/geoserver/data/...".
 *</p>
 * @author Justin Deoliveira, The Open Planning Project
 *
 */
@SuppressWarnings("serial")
public class DataDirectoryConverterLocator implements IConverterLocator {

    static final Logger LOGGER = Logging.getLogger(DataDirectoryConverterLocator.class);
    GeoServerResourceLoader resourceLoader;
    
    public DataDirectoryConverterLocator( GeoServerResourceLoader resourceLoader ) {
        this.resourceLoader = resourceLoader;
    }
    
    @SuppressWarnings("unchecked")
    public <C> IConverter<C> getConverter(Class<C> type) {
        if ( File.class.isAssignableFrom( type ) ) {
            return (IConverter<C>) new FileLocator();
        }
        if ( URL.class.isAssignableFrom( type ) ) {
            return (IConverter<C>) new URLLocator();
        }
        if ( URI.class.isAssignableFrom( type ) ) {
            return (IConverter<C>) new URILocator();
        }
        
        return null;
    }

    File toFile( String value ) {
        if ( value == null || "".equals( value ) ) {
            return null;
        }
        try {
            //first try as a url to strip off url protocol prefix
            try {
                URL url = new URL( value );
                if ( "file".equals( url.getProtocol() ) ) {
                    value = url.getFile();
                }
            }
            catch( MalformedURLException e ) {}
            
            File file = new File( value );
            if ( file.isAbsolute() ) {
                return file;
            }

            return resourceLoader.find( value );
        } 
        catch (IOException e) {
            LOGGER.log(Level.WARNING, "Error converting \""+value+"\" to File", e);
        }
        
        return null;
    }
    
    String fromFile( File file ) {
        File data = resourceLoader.getBaseDirectory();
        
        //figure out if the file is a child of the base data directory
        List<String> path = new ArrayList<String>();
        boolean isChild = false;
        while( file != null ) {
            if ( file.equals( data ) ) {
                isChild = true;
                break;
            }
            
            path.add( file.getName() );
            file = file.getParentFile();
        }
        
        if ( isChild ) {
            StringBuffer b = new StringBuffer( "file:" );
            for ( int i = path.size()-1; i > -1; i--)  {
                b.append( path.get( i ) ).append( File.separatorChar );
            }
            b.setLength( b.length()-1 );
            return b.toString();
        }
        
        return null;
    }
    
    class FileLocator implements IConverter<File> {

        public File convertToObject(String value, Locale locale) {
            return toFile( value );
        }

        public String convertToString(File value, Locale locale) {
            return fromFile( (File) value );
        }
        
    }
    
    class URLLocator implements IConverter<URL> {

        public URL convertToObject(String value, Locale locale) {
            File file = toFile( value );
            if ( file != null ) {
                try {
                    return file.toURI().toURL();
                } 
                catch (MalformedURLException e) {
                    LOGGER.log(Level.WARNING, "Error converting \""+value+"\" to URL", e);
                }
            }
            
            return null;
        }

        public String convertToString(URL value, Locale locale) {
            String file = value.getFile();
            if ( file != null && !"".equals( file ) ) {
                return fromFile( new File( value.getFile() ) );
            }
            return null;
        }
        
    }
    
    class URILocator implements IConverter<URI> {

        public URI convertToObject(String value, Locale locale) {
            File file = toFile( value );
            if ( file != null ) {
                return file.toURI();
            }
            return null;
        }

        public String convertToString(URI value, Locale locale) {
            try {
                return new URLLocator().convertToString( value.toURL() , locale );
            } 
            catch (Exception e) {
                LOGGER.log(Level.WARNING, "Error converting \""+value+"\" to URI", e);
                return null;
            }
        }
        
    }
}