The DCL design pattern will fail 90% of the time. I was able to prove
this a while back when I removed the DCL pattern from the transaction
factory and connection factory.
I recommend using an atomic reference.
Adrian Crum
Sandglass Software
www.sandglass-software.com
On 9/3/2014 10:10 AM, [email protected] wrote:
Author: jacopoc
Date: Wed Sep 3 09:10:04 2014
New Revision: 1622193
URL: http://svn.apache.org/r1622193
Log:
Greatly simplified the UtilJ2eeCompat class by removing a series of variables
and methods no more in use.
The class was not thread safe and this didn't cause particular issues
probably just because all the threads using it were passing ServletContext with
the same server info value (because they were associated to the same servlet
container); it was however inefficient.
Now it is thread safe using the DCL pattern which I usually tend to avoid but
is useful here.
However this class should probably go away but before taking a decision I
will start a discussion in the dev list.
Modified:
ofbiz/trunk/framework/base/src/org/ofbiz/base/util/UtilJ2eeCompat.java
Modified: ofbiz/trunk/framework/base/src/org/ofbiz/base/util/UtilJ2eeCompat.java
URL:
http://svn.apache.org/viewvc/ofbiz/trunk/framework/base/src/org/ofbiz/base/util/UtilJ2eeCompat.java?rev=1622193&r1=1622192&r2=1622193&view=diff
==============================================================================
--- ofbiz/trunk/framework/base/src/org/ofbiz/base/util/UtilJ2eeCompat.java
(original)
+++ ofbiz/trunk/framework/base/src/org/ofbiz/base/util/UtilJ2eeCompat.java Wed
Sep 3 09:10:04 2014
@@ -28,74 +28,60 @@ public class UtilJ2eeCompat {
public static final String module = UtilJ2eeCompat.class.getName();
- public static final String TOMCAT = "apache tomcat";
- public static final String ORION = "orion";
- public static final String RESIN = "resin";
- public static final String REX_IP = "tradecity";
- public static final String OC4J = "oracle";
- public static final String JRUN = "jrun";
- public static final String JETTY = "jetty";
- public static final String WEBSPHERE = "websphere";
-
- protected static Boolean doFlushOnRenderValue = null;
- protected static Boolean useOutputStreamNotWriterValue = null;
- protected static Boolean useNestedJspException = null;
-
- public static boolean doFlushOnRender(ServletContext context) {
- initCompatibilityOptions(context);
- return doFlushOnRenderValue.booleanValue();
- }
-
- public static boolean useOutputStreamNotWriter(ServletContext context) {
- initCompatibilityOptions(context);
- return useOutputStreamNotWriterValue.booleanValue();
- }
+ private static final String TOMCAT = "apache tomcat";
+ private static final String ORION = "orion";
+ private static final String REX_IP = "tradecity";
+ private static final String JRUN = "jrun";
+ private static final String JETTY = "jetty";
+ private static final String WEBSPHERE = "websphere";
+
+ private volatile static UtilJ2eeCompat instance;
+
+ private final boolean useOutputStreamNotWriter;
+
+ private UtilJ2eeCompat(ServletContext context) {
+ boolean usestream = true;
+ // if context is null use an empty string here which will cause the
defaults to be used
+ String serverInfo = context == null ? "" :
context.getServerInfo().toLowerCase();
+
+ Debug.logInfo("serverInfo: " + serverInfo, module);
+
+ if (serverInfo.indexOf(TOMCAT) >= 0) {
+ Debug.logInfo("Apache Tomcat detected, using response.getWriter to
write text out instead of response.getOutputStream", module);
+ usestream = false;
+ } else if (serverInfo.indexOf(REX_IP) >= 0) {
+ Debug.logInfo("Trade City RexIP detected, using response.getWriter to
write text out instead of response.getOutputStream", module);
+ usestream = false;
+ } else if (serverInfo.indexOf(JRUN) >= 0) {
+ Debug.logInfo("JRun detected, using response.getWriter to write text
out instead of response.getOutputStream", module);
+ usestream = false;
+ } else if (serverInfo.indexOf(JETTY) >= 0) {
+ Debug.logInfo("Jetty detected, using response.getWriter to write text
out instead of response.getOutputStream", module);
+ usestream = false;
+ } else if (serverInfo.indexOf(ORION) >= 0) {
+ Debug.logInfo("Orion detected, using response.getWriter to write text
out instead of response.getOutputStream", module);
+ usestream = false;
+ } else if (serverInfo.indexOf(WEBSPHERE) >= 0) {
+ Debug.logInfo("IBM Websphere Application Server detected, using
response.getWriter to write text out instead of response.getOutputStream", module);
+ usestream = false;
+ }
- public static boolean useNestedJspException(ServletContext context) {
- initCompatibilityOptions(context);
- return useNestedJspException.booleanValue();
+ useOutputStreamNotWriter = usestream;
}
- protected static void initCompatibilityOptions(ServletContext context) {
- // this check to see if we should flush is done because on most
servers this
- // will just slow things down and not solve any problems, but on
Tomcat, Orion, etc it is necessary
- if (useOutputStreamNotWriterValue == null || doFlushOnRenderValue ==
null) {
- boolean doflush = true;
- boolean usestream = true;
- boolean nestjspexception = true;
- // if context is null use an empty string here which will cause
the defaults to be used
- String serverInfo = context == null ? "" :
context.getServerInfo().toLowerCase();
-
- Debug.logInfo("serverInfo: " + serverInfo, module);
-
- if (serverInfo.indexOf(RESIN) >= 0) {
- Debug.logInfo("Resin detected, disabling the flush on the region
render from PageContext for better performance", module);
- doflush = false;
- } else if (serverInfo.indexOf(REX_IP) >= 0) {
- Debug.logInfo("Trade City RexIP detected, using response.getWriter
to write text out instead of response.getOutputStream", module);
- usestream = false;
- } else if (serverInfo.indexOf(TOMCAT) >= 0) {
- Debug.logInfo("Apache Tomcat detected, using response.getWriter to
write text out instead of response.getOutputStream", module);
- usestream = false;
- } else if (serverInfo.indexOf(JRUN) >= 0) {
- Debug.logInfo("JRun detected, using response.getWriter to write
text out instead of response.getOutputStream", module);
- usestream = false;
- } else if (serverInfo.indexOf(JETTY) >= 0) {
- Debug.logInfo("Jetty detected, using response.getWriter to write
text out instead of response.getOutputStream", module);
- usestream = false;
- } else if (serverInfo.indexOf(ORION) >= 0) {
- Debug.logInfo("Orion detected, using response.getWriter to write
text out instead of response.getOutputStream", module);
- usestream = false;
- Debug.logInfo("Orion detected, using non-nested JspException",
module);
- nestjspexception = false;
- } else if (serverInfo.indexOf(WEBSPHERE) >= 0) {
- Debug.logInfo("IBM Websphere Application Server detected, using
response.getWriter to write text out instead of response.getOutputStream", module);
- usestream = false;
+ private static UtilJ2eeCompat getInstance(ServletContext context) {
+ if (instance == null) {
+ synchronized (UtilJ2eeCompat.class) {
+ if (instance == null) {
+ instance = new UtilJ2eeCompat(context);
+ }
}
-
- doFlushOnRenderValue = Boolean.valueOf(doflush);
- useOutputStreamNotWriterValue = Boolean.valueOf(usestream);
- useNestedJspException = Boolean.valueOf(nestjspexception);
}
+ return instance;
}
+
+ public static boolean useOutputStreamNotWriter(ServletContext context) {
+ return getInstance(context).useOutputStreamNotWriter;
+ }
+
}
