Merged HEAD-BUG-FIX (5.1/Cloud) to HEAD (5.1/Cloud)

106239: Merge RA-SPRINT6 to HEAD-BUG-FIX (5.1)
      106158: RA-302: Fix the startup issue being encountered when Cloud is built locally


git-svn-id: https://svn.alfresco.com/repos/alfresco-enterprise/alfresco/HEAD/root@106316 c4b6b30b-aa2e-2d43-bbcb-ca4b014f7261

source/java/org/alfresco/web/scripts/servlet/StaticAssetCacheFilter.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2005-2010 Alfresco Software Limited.
+ *
+ * This file is part of Alfresco
+ *
+ * Alfresco is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Alfresco is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.alfresco.web.scripts.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.HttpServletResponse;
+
+/**
+ * Simple servlet filter to add a 'Cache-Control' HTTP header to a response.
+ * The Cache-Control header is set to a max-age value by a configurable setting
+ * in the 'expires' init parameters - values are in days.
+ * 
+ * WebScripts or other servlets that happen to match the response type
+ * configured for the filter (e.g. "*.js") should override cache settings
+ * as required.
+ * 
+ * @author Kevin Roast
+ */
+public class StaticAssetCacheFilter implements Filter
+{
+    private static final long DAY_S = 60L*60L*24L;          // 1 day in seconds
+    private static final long DEFAULT_30DAYS = 30L;         // default of 30 days if not configured
+    
+    private long expire = DAY_S * DEFAULT_30DAYS;           // initially set to default value of 30 days
+    
+    
+    /* (non-Javadoc)
+     * @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
+     */
+    public void init(FilterConfig config) throws ServletException
+    {
+        String expireParam = config.getInitParameter("expires");
+        if (expireParam != null)
+        {
+            this.expire = Long.parseLong(expireParam) * DAY_S;
+        }
+    }
+    
+    /* (non-Javadoc)
+     * @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
+     */
+    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException,
+            ServletException
+    {
+        ((HttpServletResponse)res).setHeader("Cache-Control", "must-revalidate, max-age=" + Long.toString(this.expire));
+        chain.doFilter(req, res);
+    }
+    
+    /* (non-Javadoc)
+     * @see javax.servlet.Filter#destroy()
+     */
+    public void destroy()
+    {
+        this.expire = DAY_S * DEFAULT_30DAYS;
+    }
+}