From a83753b73562123e35b76fe91a173033a01e2bc2 Mon Sep 17 00:00:00 2001
From: Tsz-wo Sze <szetszwo@apache.org>
Date: Mon, 7 Nov 2011 20:51:15 +0000
Subject: [PATCH] HADOOP-7688. Add servlet handler check in HttpServer.start().
  Contributed by Uma Maheswara Rao G

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1198924 13f79535-47bb-0310-9956-ffa450edef68
---
 .../hadoop-common/CHANGES.txt                 |  5 ++-
 .../org/apache/hadoop/http/HttpServer.java    |  8 +++++
 .../apache/hadoop/http/TestServletFilter.java | 34 ++++++++++++++++++-
 3 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/hadoop-common-project/hadoop-common/CHANGES.txt b/hadoop-common-project/hadoop-common/CHANGES.txt
index f559cbb9cc..7eafd25a90 100644
--- a/hadoop-common-project/hadoop-common/CHANGES.txt
+++ b/hadoop-common-project/hadoop-common/CHANGES.txt
@@ -55,7 +55,10 @@ Trunk (unreleased changes)
     HADOOP-7792. Add verifyToken method to AbstractDelegationTokenSecretManager.
     (jitendra)
 
-		HADOOP-7776 Make the Ipc-Header in a RPC-Payload an explicit header (sanjay)
+    HADOOP-7776 Make the Ipc-Header in a RPC-Payload an explicit header (sanjay)
+
+    HADOOP-7688. Add servlet handler check in HttpServer.start().
+    (Uma Maheswara Rao G via szetszwo)
 
   BUGS
 
diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/http/HttpServer.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/http/HttpServer.java
index ccc72edacf..e529e789ed 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/http/HttpServer.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/http/HttpServer.java
@@ -707,6 +707,14 @@ public void start() throws IOException {
           listener.setPort((oriPort += 1));
         }
       }
+      // Make sure there is no handler failures.
+      Handler[] handlers = webServer.getHandlers();
+      for (int i = 0; i < handlers.length; i++) {
+        if (handlers[i].isFailed()) {
+          throw new IOException(
+              "Problem in starting http server. Server handlers failed");
+        }
+      }
     } catch (IOException e) {
       throw e;
     } catch (InterruptedException e) {
diff --git a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/http/TestServletFilter.java b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/http/TestServletFilter.java
index 6cd21beb1b..7bf608767e 100644
--- a/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/http/TestServletFilter.java
+++ b/hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/http/TestServletFilter.java
@@ -45,7 +45,7 @@ public class TestServletFilter extends HttpServerFunctionalTest {
   static public class SimpleFilter implements Filter {
     private FilterConfig filterConfig = null;
 
-    public void init(FilterConfig filterConfig) {
+    public void init(FilterConfig filterConfig) throws ServletException {
       this.filterConfig = filterConfig;
     }
 
@@ -137,4 +137,36 @@ public void testServletFilter() throws Exception {
       http.stop();
     }
   }
+  
+  static public class ErrorFilter extends SimpleFilter {
+    @Override
+    public void init(FilterConfig arg0) throws ServletException {
+      throw new ServletException("Throwing the exception from Filter init");
+    }
+
+    /** Configuration for the filter */
+    static public class Initializer extends FilterInitializer {
+      public Initializer() {
+      }
+
+      public void initFilter(FilterContainer container, Configuration conf) {
+        container.addFilter("simple", ErrorFilter.class.getName(), null);
+      }
+    }
+  }
+
+  @Test
+  public void testServletFilterWhenInitThrowsException() throws Exception {
+    Configuration conf = new Configuration();
+    // start a http server with CountingFilter
+    conf.set(HttpServer.FILTER_INITIALIZER_PROPERTY,
+        ErrorFilter.Initializer.class.getName());
+    HttpServer http = createTestServer(conf);
+    try {
+      http.start();
+      fail("expecting exception");
+    } catch (IOException e) {
+      assertTrue( e.getMessage().contains("Problem in starting http server. Server handlers failed"));
+    }
+  }
 }