improved the diagnosability when the explode() method fails

git-svn-id: https://hudson.dev.java.net/svn/hudson/trunk/hudson/main@11973 71c3de6d-444a-0410-be80-ed276b4c234a

test/src/main/java/org/jvnet/hudson/test/HudsonTestCase.java

@@ -161,7 +161,7 @@ public abstract class HudsonTestCase extends TestCase {
     protected ServletContext createWebServer() throws Exception {
         server = new Server();
 
-        WebAppContext context = new WebAppContext(WarExploder.EXPLODE_DIR.getPath(), contextPath);
+        WebAppContext context = new WebAppContext(WarExploder.getExplodedDir().getPath(), contextPath);
         context.setClassLoader(getClass().getClassLoader());
         context.setConfigurations(new Configuration[]{new WebXmlConfiguration(),new NoListenerConfiguration()});
         server.setHandler(context);

test/src/main/java/org/jvnet/hudson/test/WarExploder.java

@@ -4,7 +4,6 @@ import hudson.remoting.Which;
 import hudson.FilePath;
 
 import java.io.File;
-import java.io.IOException;
 import java.io.FileOutputStream;
 import java.net.URL;
 
@@ -14,13 +13,30 @@ import java.net.URL;
  * @author Kohsuke Kawaguchi
  */
 final class WarExploder {
-    public static final File EXPLODE_DIR = explode();
+
+    public static File getExplodedDir() throws Exception {
+        // rethrow an exception every time someone tries to do this, so that when explode()
+        // fails, you can see the cause no matter which test case you look at.
+        // see http://www.nabble.com/Failing-tests-in-test-harness-module-on-hudson.ramfelt.se-td19258722.html
+        if(FAILURE !=null)   throw new Exception("Failed to initialize exploded war", FAILURE);
+        return EXPLODE_DIR;
+    }
+
+    private static File EXPLODE_DIR;
+    private static Exception FAILURE;
+
+    static {
+        try {
+            EXPLODE_DIR = explode();
+        } catch (Exception e) {
+            FAILURE = e;
+        }
+    }
 
     /**
      * Explodes hudson.war, if necesasry, and returns its root dir.
      */
-    private static File explode() {
-        try {
+    private static File explode() throws Exception {
         // are we in the hudson main workspace? If so, pick up hudson/main/war/resources
         // this saves the effort of packaging a war file and makes the debug cycle faster
         File d = new File(".").getAbsoluteFile();
@@ -59,12 +75,5 @@ final class WarExploder {
         }
 
         return explodeDir;
-        } catch (IOException e) {
-            throw new Error(e);
-        } catch (InterruptedException e) {
-            throw new Error(e);
-        } catch (ClassNotFoundException e) {
-            throw new Error(e);
-        }
     }
 }