ServletMapping.java

/*
 * Copyright (c) 1998-2012 Caucho Technology -- all rights reserved
 *
 * This file is part of Resin(R) Open Source
 *
 * Each copy or derived work must preserve the copyright notice and this
 * notice unmodified.
 *
 * Resin Open Source is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Resin Open Source is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
 * of NON-INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Resin Open Source; if not, write to the
 *
 *   Free Software Foundation, Inc.
 *   59 Temple Place, Suite 330
 *   Boston, MA 02111-1307  USA
 *
 * @author Scott Ferguson
 */

package org.ireland.jnetty.dispatch.servlet;

import java.util.ArrayList;
import java.util.Collection;


import org.ireland.jnetty.config.ConfigException;
import org.ireland.jnetty.dispatch.FilterChainInvocation;
import org.springframework.util.Assert;



/**
 * Configuration for a servlet.
 * 
 * 代表web.xml中一个"<servlet-mapping>"元素
 * 
 *   <servlet-mapping>
 *       <servlet-name>MyServlet</servlet-name>
 *       <url-pattern>/myservlet.do</url-pattern>
 *       <url-pattern>/my/*</url-pattern>
 *       <url-pattern>/mys/*</url-pattern>
 *   </servlet-mapping>
 * 
 */
public class ServletMapping
{

	// <servlet>
	private final ServletConfigImpl servletConfig;

	// <url-pattern> 列表
	private ArrayList<String> _urlPatterns = new ArrayList<String>();


	/**
	 * Creates a new servlet mapping object.
	 */
	public ServletMapping(ServletConfigImpl servletConfig)
	{
		Assert.notNull(servletConfig);

		this.servletConfig = servletConfig;
	}

	public ServletConfigImpl getServletConfig()
	{
		return servletConfig;
	}

	/**
	 * Gets the url patterns
	 */

	public Collection<String> getURLPatterns()
	{
		return _urlPatterns;
	}

	/**
	 * Sets the url pattern
	 */
	public void addURLPattern(String pattern)
	{
		if (pattern.indexOf('\n') > -1)
		{
			throw new ConfigException("'url-pattern' cannot contain newline");
		}

		if(_urlPatterns.contains(pattern))		//not to add the exist parrern
			return;
		
		_urlPatterns.add(pattern);

		// server/13f4
		if (servletConfig.getServletNameDefault() == null)
			servletConfig.setServletNameDefault(pattern);
	}



	// ------------------------------------------------------------------

	/**
	 * Returns true if the servlet-mapping matches the invocation URL.
	 * 
	 * @param invocation
	 *            the request's invocation
	 */
	boolean isMatch(FilterChainInvocation invocation)
	{
		return isMatch(invocation.getServletPath(), invocation.getPathInfo());
	}
	

	/**
	 * Returns true if the servlet-mapping matches the servlet path and path info.
	 * */
	public boolean isMatch(String servletPath, String pathInfo)
	{
		String uri;

		if (pathInfo == null)
			uri = servletPath;
		else if (servletPath == null)
			uri = pathInfo;
		else
			uri = servletPath + pathInfo;

		return isMatch(uri);
	}
	
	/**
	 * Returns true if the servlet-mapping matches the URI
	 * 
	 * @param uri
	 *            the request's uri(= servletPath + pathInfo)
	 */
	public boolean isMatch(String uri)
	{
		for (String urlPattern : _urlPatterns)
		{
			if (matchServletURL(uri,urlPattern) )
				return true;
		}

		return false;
	}


	/**
	 * Return <code>true</code> if the context-relative request path matches the requirements of the specified filter
	 * mapping; otherwise, return <code>false</code>.
	 * 
	 * 
	 * @param requestPath
	 *            Context-relative request path of this request(without query String)
	 * 
	 * @param urlPattern
	 *            URL mapping being checked
	 */
	private static boolean matchServletURL(String requestPath , String urlPattern)
	{

		if (urlPattern == null)
			return (false);

		// Case 1 - Exact Match
		if (urlPattern.equals(requestPath))
			return (true);

		// Case 2 - Path Match ("/.../*")
		if (urlPattern.equals("/*"))
			return (true);
		if (urlPattern.endsWith("/*"))
		{
			if (urlPattern.regionMatches(0, requestPath, 0, urlPattern.length() - 2))
			{
				if (requestPath.length() == (urlPattern.length() - 2))
				{
					return (true);
				}
				else if ('/' == requestPath.charAt(urlPattern.length() - 2))
				{
					return (true);
				}
			}
			return (false);
		}

		// Case 3 - Extension Match
		if (urlPattern.startsWith("*."))
		{
			int slash = requestPath.lastIndexOf('/');
			int period = requestPath.lastIndexOf('.');
			if ((slash >= 0) && (period > slash) && (period != requestPath.length() - 1) && ((requestPath.length() - period) == (urlPattern.length() - 1)))
			{
				return (urlPattern.regionMatches(2, requestPath, period + 1, urlPattern.length() - 2));
			}
		}

		// Case 4 - "Default" Match
		return (false); // NOTE - Not relevant for selecting filters

	}

	// ------------------------------------------------------------

	/**
	 * Returns a printable representation of the servlet config object.
	 */
	public String toString()
	{
		StringBuilder builder = new StringBuilder();

		builder.append("ServletMapping[");

		for (int i = 0; i < _urlPatterns.size(); i++)
		{
			String urlPattern = _urlPatterns.get(i);

			if (urlPattern != null)
			{
				builder.append("url-pattern=");
				builder.append(urlPattern);
				builder.append(", ");
			}
		}

		builder.append("name=");
		builder.append(servletConfig.getServletName());

		if (servletConfig.getServletClassName() != null)
		{
			builder.append(", class=");
			builder.append(servletConfig.getServletClassName());
		}

		builder.append("]");

		return builder.toString();
	}

}