Hi Claus,
Thanks for point issue out.
I added a lock on loading the class, it should be better now ;)
Willem
Claus Ibsen wrote:
On Fri, Dec 18, 2009 at 11:20 AM, Claus Ibsen <claus.ib...@gmail.com> wrote:
Hi
Actually the AtomicBoolean cannot safely be used for initializing code blocks?
You can still have concurrent threads invoking the boolean and one
thread will see it as false and the other as true.
What it helps is that there are only one ever that sees it as false
and therefore only one thread that will initialize it.
But in the mean time another thread could have seen it as true, but
its still not initialized because the first thread is currently doing
that.
e.g. there are no locks.
You have to use the synchronized or a Lock object.
See for example camel-jaxb and how it use the synchronized.
Its not bad to use as synchronized is heavily optimized in JDK6.
A better idea would be to implements Service (extends ServiceSupport)
and do initialization in the start method.
I am pretty sure Camel will invoke these start/stop on data formats as
well. Could you try that? If not we should get that done.
Then all kind of initialization can be done using the Service interface.
Ah yeah you need to do it at runtime sine you need access to CamelContext.
I wonder if implementing CamelContextAware is sufficient?
On Fri, Dec 18, 2009 at 10:54 AM, <ningji...@apache.org> wrote:
Author: ningjiang
Date: Fri Dec 18 09:54:30 2009
New Revision: 892199
URL: http://svn.apache.org/viewvc?rev=892199&view=rev
Log:
CAMEL-2148 using the ClassResolver from the CamelContext to load class
Modified:
camel/trunk/components/camel-protobuf/src/main/java/org/apache/camel/dataformat/protobuf/ProtobufDataFormat.java
Modified:
camel/trunk/components/camel-protobuf/src/main/java/org/apache/camel/dataformat/protobuf/ProtobufDataFormat.java
URL:
http://svn.apache.org/viewvc/camel/trunk/components/camel-protobuf/src/main/java/org/apache/camel/dataformat/protobuf/ProtobufDataFormat.java?rev=892199&r1=892198&r2=892199&view=diff
==============================================================================
---
camel/trunk/components/camel-protobuf/src/main/java/org/apache/camel/dataformat/protobuf/ProtobufDataFormat.java
(original)
+++
camel/trunk/components/camel-protobuf/src/main/java/org/apache/camel/dataformat/protobuf/ProtobufDataFormat.java
Fri Dec 18 09:54:30 2009
@@ -20,10 +20,12 @@
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Method;
+import java.util.concurrent.atomic.AtomicBoolean;
import com.google.protobuf.Message;
import com.google.protobuf.Message.Builder;
+import org.apache.camel.CamelContext;
import org.apache.camel.CamelException;
import org.apache.camel.Exchange;
import org.apache.camel.InvalidPayloadException;
@@ -34,6 +36,8 @@
public class ProtobufDataFormat implements DataFormat {
private Message defaultInstance;
+ private String instanceClassName;
+ private AtomicBoolean setDefaultInstanceHasBeenCalled = new
AtomicBoolean(false);
/**
* @param defaultInstance
@@ -51,11 +55,15 @@
public void setInstanceClass(String className) throws Exception {
ObjectHelper.notNull(className, "ProtobufDataFormat instaceClass");
- Class<?> instanceClass = ObjectHelper.loadClass(className);
+ instanceClassName = className;
+ }
+
+ protected Message loadDefaultInstance(String className, CamelContext
context) throws CamelException, ClassNotFoundException {
+ Class<?> instanceClass =
context.getClassResolver().resolveMandatoryClass(className);
if (Message.class.isAssignableFrom(instanceClass)) {
try {
Method method = instanceClass.getMethod("getDefaultInstance",
new Class[0]);
- defaultInstance = (Message) method.invoke(null, new Object[0]);
+ return (Message) method.invoke(null, new Object[0]);
} catch (Exception ex) {
throw new CamelException("Can't set the defaultInstance of
ProtobufferDataFormat with "
+ className + ", caused by " + ex);
@@ -64,7 +72,6 @@
throw new CamelException("Can't set the defaultInstance of
ProtobufferDataFormat with "
+ className + ", as the class is not a subClass of
com.google.protobuf.Message");
}
-
}
/*
@@ -82,8 +89,15 @@
* java.io.InputStream)
*/
public Object unmarshal(Exchange exchange, InputStream inputStream) throws
Exception {
+
if (this.defaultInstance == null) {
- throw new CamelException("There is not defaultInstance for protobuf
unmarshaling");
+ if (instanceClassName == null) {
+ throw new CamelException("There is not defaultInstance for protobuf
unmarshaling");
+ } else {
+ if (!setDefaultInstanceHasBeenCalled.getAndSet(true)) {
+ defaultInstance = loadDefaultInstance(instanceClassName,
exchange.getContext());
+ }
+ }
}
Builder builder =
this.defaultInstance.newBuilderForType().mergeFrom(inputStream);
if (!builder.isInitialized()) {
--
Claus Ibsen
Apache Camel Committer
Author of Camel in Action: http://www.manning.com/ibsen/
Open Source Integration: http://fusesource.com
Blog: http://davsclaus.blogspot.com/
Twitter: http://twitter.com/davsclaus
