dtdentityresolver.java

一个很好实用的工作流OSWORKFLOW开发例子.有着非常优秀的灵活性.

/*
 * Copyright (c) 2002-2003 by OpenSymphony
 * All rights reserved.
 */
package com.opensymphony.workflow.loader;

import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;

import java.io.IOException;
import java.io.InputStream;

import java.net.MalformedURLException;
import java.net.URL;


/**
 * @author Hani Suleiman ([e-mail])
 * Date: Sep 14, 2003
 * Time: 4:25:40 PM
 */
public class DTDEntityResolver implements EntityResolver {
    //~ Methods ////////////////////////////////////////////////////////////////

    public InputSource resolveEntity(String publicId, String systemId) throws SAXException, IOException {
        if (systemId == null) {
            return null;
        }

        try {
            URL url = new URL(systemId);
            String file = url.getFile();

            if ((file != null) && (file.indexOf('/') > -1)) {
                file = file.substring(file.lastIndexOf('/') + 1);
            }

            if ("www.opensymphony.com".equals(url.getHost()) && systemId.endsWith(".dtd")) {
                InputStream is = getClass().getResourceAsStream("/META-INF/" + file);

                if (is == null) {
                    is = getClass().getResourceAsStream('/' + file);
                }

                if (is != null) {
                    return new InputSource(is);
                }
            }
        }
        //modified by mbussetti - 15 nov 2004
        //if the systemId isn't an URL, it is searched in the usual classpath
         catch (MalformedURLException e) {
            InputStream is = getClass().getResourceAsStream("/META-INF/" + systemId);

            if (is == null) {
                is = getClass().getResourceAsStream('/' + systemId);
            }

            if (is != null) {
                return new InputSource(is);
            }
        }

        return null;
    }
}