SPR-5628 Add HttpPutFormContentFilter in order to make form encoded data available via ServletRequest.getParameter*()

org.springframework.web/src/main/java/org/springframework/web/filter/HttpPutFormContentFilter.java

@@ -0,0 +1,151 @@
+/*
+ * Copyright 2002-2011 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.springframework.web.filter;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.LinkedHashMap;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+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.http.HttpInputMessage;
+import org.springframework.http.converter.FormHttpMessageConverter;
+import org.springframework.http.converter.xml.XmlAwareFormHttpMessageConverter;
+import org.springframework.http.server.ServletServerHttpRequest;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+
+/**
+ * {@link javax.servlet.Filter} that makes form encoded data available through the 
+ * {@code ServletRequest.getParameter*()} family of methods during HTTP PUT requests.
+ *  
+ * <p>The Servlet spec requires form data to be available for HTTP POST but not for
+ * HTTP PUT requests. This filter intercepts HTTP PUT requests  
+ * where {@code 'Content-Type:application/x-www-form-urlencoded'}, reads the form
+ * data from the body of the request, and wraps the ServletRequest in order to make
+ * the form data available as request parameters.
+ * 
+ * @author Rossen Stoyanchev
+ * @since 3.1
+ */
+public class HttpPutFormContentFilter extends OncePerRequestFilter {
+
+	private static final String FORM_CONTENT_TYPE = "application/x-www-form-urlencoded";
+	
+	private final FormHttpMessageConverter formConverter = new XmlAwareFormHttpMessageConverter();
+	
+	/**
+	 * The default character set to use for reading form data.
+	 */
+	public void setCharset(Charset charset) {
+		this.formConverter.setCharset(charset);
+	}
+
+	@Override
+	protected void doFilterInternal(final HttpServletRequest request, HttpServletResponse response, FilterChain filterChain)
+			throws ServletException, IOException {
+
+		if ("PUT".equals(request.getMethod()) && isFormContentType(request)) {
+			HttpInputMessage inputMessage = new ServletServerHttpRequest(request) {
+				@Override
+				public InputStream getBody() throws IOException {
+					return request.getInputStream();
+				}
+			};
+			MultiValueMap<String, String> formParameters = formConverter.read(null, inputMessage);
+			HttpServletRequest wrapper = new HttpPutFormContentRequestWrapper(request, formParameters);
+			filterChain.doFilter(wrapper, response);
+		}
+		else {
+			filterChain.doFilter(request, response);
+		}
+
+	}
+
+	private boolean isFormContentType(HttpServletRequest request) {
+		String contentType = request.getContentType();
+		return ((contentType != null) && contentType.equals(FORM_CONTENT_TYPE));
+	}
+
+	private static class HttpPutFormContentRequestWrapper extends HttpServletRequestWrapper {
+		
+		private MultiValueMap<String, String> formParameters;
+
+		public HttpPutFormContentRequestWrapper(HttpServletRequest request, MultiValueMap<String, String> parameters) {
+			super(request);
+			this.formParameters = (parameters != null) ? parameters : new LinkedMultiValueMap<String, String>();
+		}
+
+		@Override
+		public String getParameter(String name) {
+			String queryStringValue = super.getParameter(name);
+			String formValue = this.formParameters.getFirst(name);
+			return (queryStringValue != null) ?  queryStringValue : formValue;
+		}
+
+		@Override
+		public Map<String, String[]> getParameterMap() {
+			Map<String, String[]> result = new LinkedHashMap<String, String[]>();
+			Enumeration<String> names = this.getParameterNames();
+			while (names.hasMoreElements()) {
+				String name = names.nextElement();
+				result.put(name, this.getParameterValues(name));
+			}
+			return result;
+		}
+
+		@Override
+		public Enumeration<String> getParameterNames() {
+			Set<String> names = new LinkedHashSet<String>();
+			names.addAll(Collections.list(super.getParameterNames()));
+			names.addAll(this.formParameters.keySet());
+			return Collections.enumeration(names);
+		}
+
+		@Override
+		public String[] getParameterValues(String name) {
+			String[] queryStringValues = super.getParameterValues(name);
+			List<String> formValues = this.formParameters.get(name);
+			if (formValues == null) {
+				return queryStringValues;
+			}
+			else if (queryStringValues == null) {
+				return formValues.toArray(new String[formValues.size()]);
+			}
+			else {
+				List<String> result = new ArrayList<String>();
+				result.addAll(Arrays.asList(queryStringValues));
+				result.addAll(formValues);
+				return result.toArray(new String[result.size()]);
+			}
+		}
+	}
+
+}