/*
* Copyright 2004-2005 the original author or authors.
*
* 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 org.grails.web.filters;
import java.io.IOException;
import javax.servlet.FilterChain;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
import org.springframework.util.Assert;
import org.springframework.util.StringUtils;
import org.springframework.web.filter.OncePerRequestFilter;
/**
* Based off the Spring implementation, but also supports the X-HTTP-Method-Override HTTP header.
*
* @see org.springframework.web.filter.HiddenHttpMethodFilter
*
* @author Graeme Rocher
* @since 1.2
*/
public class HiddenHttpMethodFilter extends OncePerRequestFilter {
/** Default method parameter: <code>_method</code> */
public static final String DEFAULT_METHOD_PARAM = "_method";
private String methodParam = DEFAULT_METHOD_PARAM;
public static final String HEADER_X_HTTP_METHOD_OVERRIDE = "X-HTTP-Method-Override";
/**
* Set the parameter name to look for HTTP methods.
* @see #DEFAULT_METHOD_PARAM
*/
public void setMethodParam(String methodParam) {
Assert.hasText(methodParam, "'methodParam' must not be empty");
this.methodParam = methodParam;
}
@Override
protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
FilterChain filterChain) throws ServletException, IOException {
if ("POST".equalsIgnoreCase(request.getMethod())) {
String httpMethod = getHttpMethodOverride(request);
if (StringUtils.hasLength(httpMethod)) {
filterChain.doFilter(new HttpMethodRequestWrapper(httpMethod, request), response);
return;
}
}
filterChain.doFilter(request, response);
}
protected String getHttpMethodOverride(HttpServletRequest request) {
String httpMethod = request.getParameter(methodParam);
if (httpMethod == null) {
httpMethod = request.getHeader(HEADER_X_HTTP_METHOD_OVERRIDE);
}
return httpMethod == null ? null : httpMethod.toUpperCase();
}
/**
* Simple {@link HttpServletRequest} wrapper that returns the supplied method for
* {@link HttpServletRequest#getMethod()}.
*/
protected static class HttpMethodRequestWrapper extends HttpServletRequestWrapper {
private final String method;
public HttpMethodRequestWrapper(String method, HttpServletRequest request) {
super(request);
this.method = method;
}
@Override
public String getMethod() {
return method;
}
}
}