AccessControlFilter.java
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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 org.apache.shiro.web.filter;
import org.apache.shiro.SecurityUtils;
import org.apache.shiro.subject.Subject;
import org.apache.shiro.web.util.WebUtils;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import java.io.IOException;
/**
* Superclass for any filter that controls access to a resource and may redirect the user to the login page
* if they are not authenticated. This superclass provides the method
* {@link #saveRequestAndRedirectToLogin(javax.servlet.ServletRequest, javax.servlet.ServletResponse)}
* which is used by many subclasses as the behavior when a user is unauthenticated.
*
* @since 0.9
*/
public abstract class AccessControlFilter extends PathMatchingFilter {
/**
* Simple default login URL equal to <code>/login.jsp</code>, which can be overridden by calling the
* {@link #setLoginUrl(String) setLoginUrl} method.
*/
public static final String DEFAULT_LOGIN_URL = "/login.jsp";
/**
* Constant representing the HTTP 'GET' request method, equal to <code>GET</code>.
*/
public static final String GET_METHOD = "GET";
/**
* Constant representing the HTTP 'POST' request method, equal to <code>POST</code>.
*/
public static final String POST_METHOD = "POST";
/**
* The login url to used to authenticate a user, used when redirecting users if authentication is required.
*/
private String loginUrl = DEFAULT_LOGIN_URL;
/**
* Returns the login URL used to authenticate a user.
* <p/>
* Most Shiro filters use this url
* as the location to redirect a user when the filter requires authentication. Unless overridden, the
* {@link #DEFAULT_LOGIN_URL DEFAULT_LOGIN_URL} is assumed, which can be overridden via
* {@link #setLoginUrl(String) setLoginUrl}.
*
* @return the login URL used to authenticate a user, used when redirecting users if authentication is required.
*/
public String getLoginUrl() {
return loginUrl;
}
/**
* Sets the login URL used to authenticate a user.
* <p/>
* Most Shiro filters use this url as the location to redirect a user when the filter requires
* authentication. Unless overridden, the {@link #DEFAULT_LOGIN_URL DEFAULT_LOGIN_URL} is assumed.
*
* @param loginUrl the login URL used to authenticate a user, used when redirecting users if authentication is required.
*/
public void setLoginUrl(String loginUrl) {
this.loginUrl = loginUrl;
}
/**
* Convenience method that acquires the Subject associated with the request.
* <p/>
* The default implementation simply returns
* {@link org.apache.shiro.SecurityUtils#getSubject() SecurityUtils.getSubject()}.
*
* @param request the incoming <code>ServletRequest</code>
* @param response the outgoing <code>ServletResponse</code>
* @return the Subject associated with the request.
*/
protected Subject getSubject(ServletRequest request, ServletResponse response) {
return SecurityUtils.getSubject();
}
/**
* Returns <code>true</code> if the request is allowed to proceed through the filter normally, or <code>false</code>
* if the request should be handled by the
* {@link #onAccessDenied(ServletRequest,ServletResponse,Object) onAccessDenied(request,response,mappedValue)}
* method instead.
*
* @param request the incoming <code>ServletRequest</code>
* @param response the outgoing <code>ServletResponse</code>
* @param mappedValue the filter-specific config value mapped to this filter in the URL rules mappings.
* @return <code>true</code> if the request should proceed through the filter normally, <code>false</code> if the
* request should be processed by this filter's
* {@link #onAccessDenied(ServletRequest,ServletResponse,Object)} method instead.
* @throws Exception if an error occurs during processing.
*/
protected abstract boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) throws Exception;
/**
* Processes requests where the subject was denied access as determined by the
* {@link #isAccessAllowed(javax.servlet.ServletRequest, javax.servlet.ServletResponse, Object) isAccessAllowed}
* method, retaining the {@code mappedValue} that was used during configuration.
* <p/>
* This method immediately delegates to {@link #onAccessDenied(ServletRequest,ServletResponse)} as a
* convenience in that most post-denial behavior does not need the mapped config again.
*
* @param request the incoming <code>ServletRequest</code>
* @param response the outgoing <code>ServletResponse</code>
* @param mappedValue the config specified for the filter in the matching request's filter chain.
* @return <code>true</code> if the request should continue to be processed; false if the subclass will
* handle/render the response directly.
* @throws Exception if there is an error processing the request.
* @since 1.0
*/
protected boolean onAccessDenied(ServletRequest request, ServletResponse response, Object mappedValue) throws Exception {
return onAccessDenied(request, response);
}
/**
* Processes requests where the subject was denied access as determined by the
* {@link #isAccessAllowed(javax.servlet.ServletRequest, javax.servlet.ServletResponse, Object) isAccessAllowed}
* method.
*
* @param request the incoming <code>ServletRequest</code>
* @param response the outgoing <code>ServletResponse</code>
* @return <code>true</code> if the request should continue to be processed; false if the subclass will
* handle/render the response directly.
* @throws Exception if there is an error processing the request.
*/
protected abstract boolean onAccessDenied(ServletRequest request, ServletResponse response) throws Exception;
/**
* Returns <code>true</code> if
* {@link #isAccessAllowed(ServletRequest,ServletResponse,Object) isAccessAllowed(Request,Response,Object)},
* otherwise returns the result of
* {@link #onAccessDenied(ServletRequest,ServletResponse,Object) onAccessDenied(Request,Response,Object)}.
*
* @return <code>true</code> if
* {@link #isAccessAllowed(javax.servlet.ServletRequest, javax.servlet.ServletResponse, Object) isAccessAllowed},
* otherwise returns the result of
* {@link #onAccessDenied(javax.servlet.ServletRequest, javax.servlet.ServletResponse) onAccessDenied}.
* @throws Exception if an error occurs.
*/
public boolean onPreHandle(ServletRequest request, ServletResponse response, Object mappedValue) throws Exception {
return isAccessAllowed(request, response, mappedValue) || onAccessDenied(request, response, mappedValue);
}
/**
* Returns <code>true</code> if the incoming request is a login request, <code>false</code> otherwise.
* <p/>
* The default implementation merely returns <code>true</code> if the incoming request matches the configured
* {@link #getLoginUrl() loginUrl} by calling
* <code>{@link #pathsMatch(String, String) pathsMatch(loginUrl, request)}</code>.
*
* @param request the incoming <code>ServletRequest</code>
* @param response the outgoing <code>ServletResponse</code>
* @return <code>true</code> if the incoming request is a login request, <code>false</code> otherwise.
*/
protected boolean isLoginRequest(ServletRequest request, ServletResponse response) {
return pathsMatch(getLoginUrl(), request);
}
/**
* Convenience method for subclasses to use when a login redirect is required.
* <p/>
* This implementation simply calls {@link #saveRequest(javax.servlet.ServletRequest) saveRequest(request)}
* and then {@link #redirectToLogin(javax.servlet.ServletRequest, javax.servlet.ServletResponse) redirectToLogin(request,response)}.
*
* @param request the incoming <code>ServletRequest</code>
* @param response the outgoing <code>ServletResponse</code>
* @throws IOException if an error occurs.
*/
protected void saveRequestAndRedirectToLogin(ServletRequest request, ServletResponse response) throws IOException {
saveRequest(request);
redirectToLogin(request, response);
}
/**
* Convenience method merely delegates to
* {@link WebUtils#saveRequest(javax.servlet.ServletRequest) WebUtils.saveRequest(request)} to save the request
* state for reuse later. This is mostly used to retain user request state when a redirect is issued to
* return the user to their originally requested url/resource.
* <p/>
* If you need to save and then immediately redirect the user to login, consider using
* {@link #saveRequestAndRedirectToLogin(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
* saveRequestAndRedirectToLogin(request,response)} directly.
*
* @param request the incoming ServletRequest to save for re-use later (for example, after a redirect).
*/
protected void saveRequest(ServletRequest request) {
WebUtils.saveRequest(request);
}
/**
* Convenience method for subclasses that merely acquires the {@link #getLoginUrl() getLoginUrl} and redirects
* the request to that url.
* <p/>
* <b>N.B.</b> If you want to issue a redirect with the intention of allowing the user to then return to their
* originally requested URL, don't use this method directly. Instead you should call
* {@link #saveRequestAndRedirectToLogin(javax.servlet.ServletRequest, javax.servlet.ServletResponse)
* saveRequestAndRedirectToLogin(request,response)}, which will save the current request state so that it can
* be reconstructed and re-used after a successful login.
*
* @param request the incoming <code>ServletRequest</code>
* @param response the outgoing <code>ServletResponse</code>
* @throws IOException if an error occurs.
*/
protected void redirectToLogin(ServletRequest request, ServletResponse response) throws IOException {
String loginUrl = getLoginUrl();
WebUtils.issueRedirect(request, response, loginUrl);
}
}