userresolverimplementation.java

ajax patterns 这是关于ajax设计模式方面的原代码

/*
    Copyright 2006 Christian Gross http://www.devspace.com
    From the book Ajax Patterns and Best Practices

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/
package devspace.ajax.permutations;
import javax.servlet.http.*;
import devspace.testDrivenDevelopment.tracer.*;

class UserImplementation implements UserIdentification {
    boolean _isIdentified;
    String _identifier;
    public UserImplementation(String identifier, boolean isIdentified) {
        _identifier = identifier;
        _isIdentified = isIdentified;
    }
    public String getIdentifier() {
        return _identifier;
    }
    public boolean isIdentified() {
        return _isIdentified;
    }
}

public class UserResolverImplementation implements UserIdentificationResolver< HttpServletRequest, HttpServletResponse> {
    protected final String constCookieIdentifier = "user-identifier";
    
    protected String getVariable(HttpServletRequest req, String identifier) {
        return req.getParameter(identifier);
    }
    
    public UserIdentification identifyUser(HttpServletRequest request, HttpServletResponse response) {
        Cookie cookie = null;
        for( Cookie testCookie : request.getCookies()) {
            if( testCookie.getName().compareTo( constCookieIdentifier) == 0) {
                cookie = testCookie;
            }
        }
        if( cookie == null) {
            GenerateOutput.Write("UserResolverImplementation.IdentifyUser", "User could not be identified trying parameters");
            String useridentifier = getVariable(request, constCookieIdentifier);
            if (useridentifier != null && useridentifier.length() > 0) {
                GenerateOutput.Write("UserResolverImplementation.IdentifyUser", "Writing Cookie");
                cookie = new Cookie(constCookieIdentifier, useridentifier);
                response.addCookie( cookie);
                return new UserImplementation(useridentifier, true);
            }
            else {
                GenerateOutput.Write("UserResolverImplementation.IdentifyUser", "User could not be identified");
                return new UserImplementation("", false);
            }
        }
        else {
            GenerateOutput.Write("UserResolverImplementation.IdentifyUser", "User identified using cookie");
            return new UserImplementation(cookie.getValue(), true);
        }
    }
}