HTTP method can be changed by POSTing with _method parameter

src/main/java/com/moandjiezana/tent/essayist/config/EssayistServletContextListener.java

@@ -93,6 +93,7 @@ public class EssayistServletContextListener extends GuiceServletContextListener
         serveRegex("/(.*)/essays").with(EssaysServlet.class);
         serveRegex("/(.*)/essay/(.*)").with(EssayServlet.class);
         filter("/*").through(Utf8Filter.class);
+        filter("/*").through(HttpMethodFilter.class);
       }
     }, new AbstractModule() {
       @Override

src/main/java/com/moandjiezana/tent/essayist/config/HttpMethodFilter.java

@@ -0,0 +1,42 @@
+package com.moandjiezana.tent.essayist.config;
+
+import com.google.common.base.Strings;
+
+import java.io.IOException;
+
+import javax.inject.Singleton;
+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.HttpServletRequestWrapper;
+
+@Singleton
+public class HttpMethodFilter implements Filter {
+
+  @Override
+  public void init(FilterConfig filterConfig) throws ServletException {}
+
+  @Override
+  public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
+    HttpServletRequest req = (HttpServletRequest) request;
+    
+    if (req.getMethod().equals("POST") && !Strings.isNullOrEmpty(req.getParameter("_method"))) {
+      req = new HttpServletRequestWrapper(req) {
+        @Override
+        public String getMethod() {
+          return getParameter("_method");
+        }
+      };
+    }
+    
+    chain.doFilter(req, response);
+  }
+
+  @Override
+  public void destroy() {}
+
+}