/*
* Copyright 2015 JBoss Inc
*
* 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 io.apiman.common.servlet;
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* A simple CORS filter for apiman.
*
* @author eric.wittmann@redhat.com
*/
public class ApimanCorsFilter implements Filter {
/**
* Constructor.
*/
public ApimanCorsFilter() {
}
/**
* @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
*/
@Override
public void init(FilterConfig config) throws ServletException {
}
/**
* @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
*/
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException,
ServletException {
HttpServletRequest httpReq = (HttpServletRequest) request;
HttpServletResponse httpResp = (HttpServletResponse) response;
if (isPreflightRequest(httpReq)) {
httpResp.setHeader("Access-Control-Allow-Origin", httpReq.getHeader("Origin")); //$NON-NLS-1$ //$NON-NLS-2$
httpResp.setHeader("Access-Control-Allow-Credentials", "true"); //$NON-NLS-1$ //$NON-NLS-2$
httpResp.setHeader("Access-Control-Max-Age", "1800"); //$NON-NLS-1$ //$NON-NLS-2$
httpResp.setHeader("Access-Control-Allow-Methods", "GET,POST,PUT,HEAD,DELETE"); //$NON-NLS-1$ //$NON-NLS-2$
httpResp.setHeader("Access-Control-Allow-Headers", "X-Requested-With,Content-Type,Accept,Origin,Authorization"); //$NON-NLS-1$ //$NON-NLS-2$
httpResp.setHeader("Access-Control-Expose-Headers", "X-Apiman-Error"); //$NON-NLS-1$ //$NON-NLS-2$
} else {
if (hasOriginHeader(httpReq)) {
httpResp.setHeader("Access-Control-Allow-Origin", httpReq.getHeader("Origin")); //$NON-NLS-1$ //$NON-NLS-2$
httpResp.setHeader("Access-Control-Allow-Credentials", "true"); //$NON-NLS-1$ //$NON-NLS-2$
httpResp.setHeader("Access-Control-Expose-Headers", "X-Apiman-Error"); //$NON-NLS-1$ //$NON-NLS-2$
}
chain.doFilter(httpReq, httpResp);
}
}
/**
* Determines whether the request is a CORS preflight request.
* @param httpReq the http servlet request
* @return true if preflight, else false
*/
private boolean isPreflightRequest(HttpServletRequest httpReq) {
return isOptionsMethod(httpReq) && hasOriginHeader(httpReq);
}
/**
* Returns true if it's an OPTIONS http request.
* @param httpReq the http servlet request
* @return true if options method, else false
*/
private boolean isOptionsMethod(HttpServletRequest httpReq) {
return "OPTIONS".equals(httpReq.getMethod()); //$NON-NLS-1$
}
/**
* Returns true if the Origin request header is present.
* @param httpReq the http servlet request
* @return true if has origin header, else false
*/
private boolean hasOriginHeader(HttpServletRequest httpReq) {
String origin = httpReq.getHeader("Origin"); //$NON-NLS-1$
return origin != null && origin.trim().length() > 0;
}
/**
* @see javax.servlet.Filter#destroy()
*/
@Override
public void destroy() {
}
}