set HTTP error codes for error conditions

fixes #17

Author: vladak

src/org/opensolaris/opengrok/configuration/RuntimeEnvironment.java

@@ -18,7 +18,7 @@
  */
 
  /*
-  * Copyright (c) 2006, 2016, Oracle and/or its affiliates. All rights reserved.
+  * Copyright (c) 2006, 2017, Oracle and/or its affiliates. All rights reserved.
   */
 package org.opensolaris.opengrok.configuration;
 
@@ -1877,6 +1877,11 @@ public MultiReader getMultiReader(SortedSet<String> projects,
             } catch (IOException ex) {
                 LOGGER.log(Level.SEVERE,
                     "cannot get IndexReader for project" + proj, ex);
+                return null;
+            } catch (NullPointerException ex) {
+                LOGGER.log(Level.SEVERE,
+                    "cannot get IndexReader for project" + proj, ex);
+                return null;
             }
         }
         MultiReader multiReader = null;

src/org/opensolaris/opengrok/web/SearchHelper.java

@@ -18,7 +18,7 @@
  */
 
 /*
- * Copyright (c) 2011, 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2017, Oracle and/or its affiliates. All rights reserved.
  * Portions copyright (c) 2011 Jens Elkner. 
  */
 package org.opensolaris.opengrok.web;
@@ -37,6 +37,7 @@
 import org.apache.lucene.document.Document;
 import org.apache.lucene.index.DirectoryReader;
 import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.index.MultiReader;
 import org.apache.lucene.index.Term;
 import org.apache.lucene.queryparser.classic.ParseException;
 import org.apache.lucene.search.BooleanQuery;
@@ -260,8 +261,13 @@ public SearchHelper prepareExec(SortedSet<String> projects) {
                 // not matter given that MultiReader is just a cheap wrapper
                 // around set of IndexReader objects.
                 closeOnDestroy = false;
-                searcher = new IndexSearcher(RuntimeEnvironment.getInstance().
-                    getMultiReader(projects, searcherList));
+                MultiReader multireader = RuntimeEnvironment.getInstance().
+                    getMultiReader(projects, searcherList);
+                if (multireader != null) {
+                    searcher = new IndexSearcher(multireader);
+                } else {
+                    errorMsg = "Failed to initialize search. Check the index.";
+                }
             }
 
             // TODO check if below is somehow reusing sessions so we don't

web/error.jsp

@@ -16,10 +16,12 @@ information: Portions Copyright [yyyy] [name of copyright owner]
 
 CDDL HEADER END
 
-Copyright (c) 2005, 2012, Oracle and/or its affiliates. All rights reserved.
+Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved.
 Portions Copyright 2011 Jens Elkner.
 
---%><%@ page session="false" isErrorPage="true" import="
+--%>
+<%@page import="javax.servlet.http.HttpServletResponse"%>
+<%@ page session="false" isErrorPage="true" import="
 java.io.PrintWriter,
 java.io.StringWriter,
 
@@ -30,9 +32,13 @@ org.opensolaris.opengrok.web.Util"
     cfg = PageConfig.get(request);
     cfg.setTitle("Error!");
 
+    // Set status to Internal error. This should help to avoid caching
+    // the page by some proxies.
+    response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
+
     String context = request.getContextPath();
     String configError = "";
-    if (cfg.getSourceRootPath()==null || cfg.getSourceRootPath().isEmpty()) {
+    if (cfg.getSourceRootPath() == null || cfg.getSourceRootPath().isEmpty()) {
         configError = "CONFIGURATION parameter has not been configured in "
             + "web.xml! Please configure your webapp.";
     } else if (!cfg.getEnv().getSourceRootFile().isDirectory()) {

web/search.jsp

@@ -18,10 +18,11 @@ information: Portions Copyright [yyyy] [name of copyright owner]
 
 CDDL HEADER END
 
-Copyright (c) 2005, 2016, Oracle and/or its affiliates. All rights reserved.
+Copyright (c) 2005, 2017, Oracle and/or its affiliates. All rights reserved.
 Portions Copyright 2011 Jens Elkner.
 
 --%>
+<%@page import="javax.servlet.http.HttpServletResponse"%>
 <%@page session="false" errorPage="error.jsp" import="
 org.opensolaris.opengrok.search.Results,
 org.opensolaris.opengrok.web.SearchHelper,
@@ -77,6 +78,9 @@ include file="projects.jspf"
     }
     if (searchHelper.errorMsg != null) {
         cfg.setTitle("Search Error");
+        // Set status to Internal error. This should help to avoid caching
+        // the page by some proxies.
+        response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
     } else {
         cfg.setTitle(cfg.getSearchTitle());
     }