IIDS forum http://www.agentscape.org/forums IIDS forum en http://backend.userland.com/rss Classpath problems in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=254#254 254@http://www.agentscape.org/forums Hi,I'm building a servlet for an agent which allows the user to upload a file to the agent.  As you probably know the native Java servlet API doesn't handle multipart forms, so I'm trying to use the Apache Commons fileupload and io libraries.With other 3rd-party libraries I've used in AgentScape I have simply copied the jar to the lib/ directory and updated the agentscape-common.mf manifest, however when I did this for the fileupload and io libraries I received an error such as this: Code: [javac] Compiling 1 source file to /home/tim/AgentScape/build/classes [javac] /home/tim/AgentScape/src/java/org/project/web/scoreServlet.java:14: package org.apache.commons.fileupload.servlet does not exist [javac] import org.apache.commons.fileupload.servlet.*; I'm probably missing something obvious here, so I've attached my agentscape-common.mf if it's any help.Any help you can give me would be fantastic,All the best,Tim Hi,

I'm building a servlet for an agent which allows the user to upload a file to the agent.  As you probably know the native Java servlet API doesn't handle multipart forms, so I'm trying to use the Apache Commons fileupload and io libraries.

With other 3rd-party libraries I've used in AgentScape I have simply copied the jar to the lib/ directory and updated the agentscape-common.mf manifest, however when I did this for the fileupload and io libraries I received an error such as this:

Code:

    [javac] Compiling 1 source file to /home/tim/AgentScape/build/classes
    [javac] /home/tim/AgentScape/src/java/org/project/web/scoreServlet.java:14: package org.apache.commons.fileupload.servlet does not exist
    [javac] import org.apache.commons.fileupload.servlet.*;

I'm probably missing something obvious here, so I've attached my agentscape-common.mf if it's any help.

Any help you can give me would be fantastic,

All the best,

Tim

]]> Wed, 10 Mar 2010 23:03:13 +0100 Servlet questions in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=253#253 253@http://www.agentscape.org/forums Hi again,I have a few questions about servlets in agentscape...1) Is it possible to add some "1st level" url which would redirect to an agent's servlet? I mean for example to be able to say that `http://lookupserver/MySuperServlet´should automatically serve the servlet from a certain agent. This would make it much easier to remember a servlet url, as it doesn't change each time I restart an agent...2) I have one servlet which takes a bit longer to compute it's response (depending on the POST data a few seconds or more); if I try and access a different servlet while the first servlet request is still "running" then it seems to mess up the two http requests; the second request receives the response from the first (as soon as the first is finished), and the first one never finishes loading... I hope this is not too confusing ;-) middleware.log logs this message: Code:2010-03-10 19:42:21,034 ERROR [btpool0-1] <> communicator.SystemServiceProxy (SystemServiceProxy.java:308) - NO ONE WAITING FOR REPLY REFID 48 Thanks,Benedit: I've attached the code which I used for testing... Hi again,

I have a few questions about servlets in agentscape...

1) Is it possible to add some "1st level" url which would redirect to an agent's servlet? I mean for example to be able to say that `http://lookupserver/MySuperServlet´
should automatically serve the servlet from a certain agent. This would make it much easier to remember a servlet url, as it doesn't change each time I restart an agent...

2) I have one servlet which takes a bit longer to compute it's response (depending on the POST data a few seconds or more); if I try and access a different servlet while the first servlet request is still "running" then it seems to mess up the two http requests; the second request receives the response from the first (as soon as the first is finished), and the first one never finishes loading...
I hope this is not too confusing ;-) middleware.log logs this message:

Code:

2010-03-10 19:42:21,034 ERROR [btpool0-1] <> communicator.SystemServiceProxy (SystemServiceProxy.java:308) - NO ONE WAITING FOR REPLY REFID 48

Thanks,
Ben

edit: I've attached the code which I used for testing...

]]> Wed, 10 Mar 2010 21:09:20 +0100 Problem with JarClassLoader and File.separatorChar in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=252#252 252@http://www.agentscape.org/forums Thank you for the example! I thought my agents were set up pretty much the same way, but I must be missing something... they are still not working while your example and a few more complicated modified versions of it are running just fine. I use netbeans' build script for the jar-file building process, so I probably have an error in there somewhere... The following is what I add in `build.xml´ and for your example this also works (I created one project for each agent, put the library files into the target agent's project and added respective library dependencies). In order for the manifest to be constructed properly main.class needs to be set in the project properties. Code: <property name="store.dir" value="../../AgentScape/agentlib"/> <target name="-post-jar"> <copy todir="${store.dir}"> <fileset dir="${dist.dir}"/> </copy> </target> Thanks again for your help! Thank you for the example! I thought my agents were set up pretty much the same way, but I must be missing something... they are still not working while your example and a few more complicated modified versions of it are running just fine.

I use netbeans' build script for the jar-file building process, so I probably have an error in there somewhere... The following is what I add in `build.xml´ and for your example this also works (I created one project for each agent, put the library files into the target agent's project and added respective library dependencies). In order for the manifest to be constructed properly main.class needs to be set in the project properties.

Code:

    <property name="store.dir" value="../../AgentScape/agentlib"/>
    <target name="-post-jar">
        <copy todir="${store.dir}">
            <fileset dir="${dist.dir}"/>
        </copy>
    </target>

Thanks again for your help!

]]> Wed, 10 Mar 2010 18:31:14 +0100 Problem with JarClassLoader and File.separatorChar in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=251#251 251@http://www.agentscape.org/forums For what it's worth, this is the example code that I used.Unzip it in the agentscape root dir, and copy the contents from build.part.xml to build.xmlGood luck! For what it's worth, this is the example code that I used.

Unzip it in the agentscape root dir, and copy the contents from build.part.xml to build.xml

Good luck!

]]> Wed, 10 Mar 2010 11:34:52 +0100 Problem with JarClassLoader and File.separatorChar in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=250#250 250@http://www.agentscape.org/forums Hello,unfortunately I have been unable to reproduce your problem.I created two agents, which both use an external library (in agentlib/lib).Sending an object from one agent to another (where the object bytecode is supplied by the library) using an AgentProxy did not produce any errors.I fear that I have no further ideas as to what could be the cause of your problem, so maybe you could supply me with more details about the setup/libraries of your agent? Hello,

unfortunately I have been unable to reproduce your problem.

I created two agents, which both use an external library (in agentlib/lib).
Sending an object from one agent to another (where the object bytecode is supplied by the library) using an AgentProxy did not produce any errors.

I fear that I have no further ideas as to what could be the cause of your problem, so maybe you could supply me with more details about the setup/libraries of your agent?

]]> Wed, 10 Mar 2010 11:27:30 +0100 Problem with JarClassLoader and File.separatorChar in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=249#249 249@http://www.agentscape.org/forums Just to make sure we are not missing anything, instantiating the class uk.ac.bath.cs.energydata.entities.Test using 'new Test()' or similar is working? It is only the deserialization that is not working? Yes, that's working. Thank you very much for having a look at this!Cheers,Ben

Just to make sure we are not missing anything, instantiating the class uk.ac.bath.cs.energydata.entities.Test using 'new Test()' or similar is working? It is only the deserialization that is not working?

Yes, that's working.

Thank you very much for having a look at this!

Cheers,
Ben

]]> Wed, 10 Mar 2010 10:19:03 +0100 Problem with JarClassLoader and File.separatorChar in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=248#248 248@http://www.agentscape.org/forums Hi Ben,if any of the libraries cannot be found then your agent would not even be able to start. So, the class path entries (and subdirectories) should be fine.We have had a look at the stack trace and will try to localize the problem.Just to make sure we are not missing anything, instantiating the class uk.ac.bath.cs.energydata.entities.Test using 'new Test()' or similar is working? It is only the deserialization that is not working?I will try to test a similar case and see what I can find.Cheers!Reinier Hi Ben,

if any of the libraries cannot be found then your agent would not even be able to start. So, the class path entries (and subdirectories) should be fine.

We have had a look at the stack trace and will try to localize the problem.


Just to make sure we are not missing anything, instantiating the class uk.ac.bath.cs.energydata.entities.Test using 'new Test()' or similar is working? It is only the deserialization that is not working?


I will try to test a similar case and see what I can find.

Cheers!
Reinier

]]> Wed, 10 Mar 2010 10:15:57 +0100 Problem with JarClassLoader and File.separatorChar in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=247#247 247@http://www.agentscape.org/forums The test class is not directly embedded in the agent jar file, but inside a referenced jar library. The library jar is in agentlib/lib/library.jar and the agent manifest references it as lib/library.jar... Having it in a subdirectory (lib) shouldn't matter, right? The test class is not directly embedded in the agent jar file, but inside a referenced jar library. The library jar is in agentlib/lib/library.jar and the agent manifest references it as lib/library.jar... Having it in a subdirectory (lib) shouldn't matter, right?

]]> Mon, 08 Mar 2010 15:48:17 +0100 Problem with JarClassLoader and File.separatorChar in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=246#246 246@http://www.agentscape.org/forums Hello,each agent receives a special class loader so it sometimes has a little bit of problems using auxiliary classes. However, if using the classes under normal circumstances (regular program code) is not a problem, then it seems strange that the unmarshalling fails to find the class.The proxy/envelope should use the context class loader (the class loader for the current thread) when reading objects.This one should be the URL class loader setup for the agent. As there is an URL class loader in the stack trace, it seems that the correct class loader is used.Is the class that you try to load (uk.ac.bath.cs.energydata.entities.Test) embedded in the agent jar file?If it is not, then you should put a reference to this library in the jar manifest (and make sure the library is present in either the lib/ or agentlib/ directory).Good luck!Reinier Hello,

each agent receives a special class loader so it sometimes has a little bit of problems using auxiliary classes. However, if using the classes under normal circumstances (regular program code) is not a problem, then it seems strange that the unmarshalling fails to find the class.

The proxy/envelope should use the context class loader (the class loader for the current thread) when reading objects.This one should be the URL class loader setup for the agent. As there is an URL class loader in the stack trace, it seems that the correct class loader is used.

Is the class that you try to load (uk.ac.bath.cs.energydata.entities.Test) embedded in the agent jar file?

If it is not, then you should put a reference to this library in the jar manifest (and make sure the library is present in either the lib/ or agentlib/ directory).

Good luck!

Reinier

]]> Mon, 08 Mar 2010 14:45:19 +0100 Problem with JarClassLoader and File.separatorChar in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=245#245 245@http://www.agentscape.org/forums Thanks, no worries. I experimented a bit with the webservice stuff but eventually decided against using it...Instead I've looked at the AgentProxyHandler example and tried to implement that... Following the example this is working nicely now, the only problem I have is a ClassNotFound exception which I get when I try to send my own classes via the proxy; primitive types and serializable java classes work fine. Code:java.lang.ClassNotFoundException: uk.ac.bath.cs.energydata.entities.Test at java.net.URLClassLoader$1.run(URLClassLoader.java:200) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:307) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301) at java.lang.ClassLoader.loadClass(ClassLoader.java:252) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:247) at org.iids.aos.util.MyObjectInputStream.resolveClass(MyObjectInputStream.java:51) at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1575) at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1496) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1732) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) at java.io.ObjectInputStream.readArray(ObjectInputStream.java:1667) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1323) at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947) at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871) at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753) at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329) at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351) at org.iids.aos.util.Marshaller.unmarshallObject(Marshaller.java:331) at org.iids.aos.messagecenter.Envelope.readObject(Envelope.java:429) at org.iids.aos.messagecenter.Envelope.getData(Envelope.java:300) at org.iids.aos.messagecenter.Envelope.getData(Envelope.java:276) at org.iids.aos.agent.proxy.AgentProxy.receiveReply(AgentProxy.java:529) at org.iids.aos.agent.proxy.AgentProxy.waitForReply(AgentProxy.java:464) at org.iids.aos.agent.proxy.AgentProxy.invoke(AgentProxy.java:185) at org.iids.aos.agent.proxy.AgentProxy.invoke(AgentProxy.java:664) ... I have the respective Class available in both agents (for the 2nd one it is contained in an imported library) and I can use it in my agent code without problem; it's only the object deserialization which isn't work... Any tipps? Cheers,Ben Thanks, no worries. I experimented a bit with the webservice stuff but eventually decided against using it...

Instead I've looked at the AgentProxyHandler example and tried to implement that... Following the example this is working nicely now, the only problem I have is a ClassNotFound exception which I get when I try to send my own classes via the proxy; primitive types and serializable java classes work fine.

Code:

java.lang.ClassNotFoundException: uk.ac.bath.cs.energydata.entities.Test
    at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
    at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:247)
    at org.iids.aos.util.MyObjectInputStream.resolveClass(MyObjectInputStream.java:51)
    at java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1575)
    at java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1496)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1732)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
    at java.io.ObjectInputStream.readArray(ObjectInputStream.java:1667)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1323)
    at java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947)
    at java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871)
    at java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753)
    at java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
    at java.io.ObjectInputStream.readObject(ObjectInputStream.java:351)
    at org.iids.aos.util.Marshaller.unmarshallObject(Marshaller.java:331)
    at org.iids.aos.messagecenter.Envelope.readObject(Envelope.java:429)
    at org.iids.aos.messagecenter.Envelope.getData(Envelope.java:300)
    at org.iids.aos.messagecenter.Envelope.getData(Envelope.java:276)
    at org.iids.aos.agent.proxy.AgentProxy.receiveReply(AgentProxy.java:529)
    at org.iids.aos.agent.proxy.AgentProxy.waitForReply(AgentProxy.java:464)
    at org.iids.aos.agent.proxy.AgentProxy.invoke(AgentProxy.java:185)
    at org.iids.aos.agent.proxy.AgentProxy.invoke(AgentProxy.java:664)
    ...

I have the respective Class available in both agents (for the 2nd one it is contained in an imported library) and I can use it in my agent code without problem; it's only the object deserialization which isn't work... Any tipps?

Cheers,
Ben

]]> Sun, 07 Mar 2010 10:58:51 +0100 Problem with JarClassLoader and File.separatorChar in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=244#244 244@http://www.agentscape.org/forums Hello Ben, and thanks for your suggestion.Of course your solution is right. We have to do more testing on windows machines to get issues like this sorted out.Unfortunately, this part of the WS-Gateway functionality is mostly experimental. We have not spent much time debugging this.We are currently restructuring the code so I do not think we will give the WS-Gateway related functions much attention. However, I will see if I can put the changes in the old trunk, so it will be available in the nightly builds for anyone that wants to use this.Thanks,Reinier Hello Ben, and thanks for your suggestion.

Of course your solution is right. We have to do more testing on windows machines to get issues like this sorted out.
Unfortunately, this part of the WS-Gateway functionality is mostly experimental. We have not spent much time debugging this.

We are currently restructuring the code so I do not think we will give the WS-Gateway related functions much attention. However, I will see if I can put the changes in the old trunk, so it will be available in the nightly builds for anyone that wants to use this.

Thanks,
Reinier

]]> Wed, 03 Mar 2010 13:13:38 +0100 Problem with JarClassLoader and File.separatorChar in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=243#243 243@http://www.agentscape.org/forums I think I found the relevant place in the apidocs... ClassLoader.getResoure() says: The name of a resource is a '/'-separated path name that identifies the resource. I think JarClassLoader.loadClass() needs to be changed... ;-) I think I found the relevant place in the apidocs... ClassLoader.getResoure() says:

The name of a resource is a '/'-separated path name that identifies the resource.

I think JarClassLoader.loadClass() needs to be changed... ;-)

]]> Mon, 01 Mar 2010 21:37:33 +0100 Problem with JarClassLoader and File.separatorChar in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=242#242 242@http://www.agentscape.org/forums Hi,I've been trying to create a webservice using the WSGateway.registerService() method; as part of that we need to create a jar containing the interface and the name of the interface class (following the provided examples...).Whenever I do this I receive an ClassNotFoundException, originally thrown by JarClassLoader.loadClass() (line 88). I've copied the file to my project and done some testing and I think I've pinpointed the error to line 72: Code:String filename = name.replace('.', File.separatorChar) + ".class"; Because I'm on a windows pc the filename is separated by backward slashes (\) in my case.Further down in the method loadClassData() method the entries are read from the JarFile, using the method jar.getNextJarEntry(). These entries are separated by a forward slash (/) on my pc. Code:entry: uk/ac/bath/cs/dataservice/ITest.class entry.entry.getName().equals(uk\ac\bath\cs\dataservice\ITest.class): false Therefore the name comparison in line 130 fails, no classData is returned and the ClassNotFound exception thrown in line 88.I haven't found any documentation on the format which the getNextJarEntry() method uses so I'm not sure if using File.separatorChar is the problem or actually something else... And ideas?Cheers,Ben Hi,

I've been trying to create a webservice using the WSGateway.registerService() method; as part of that we need to create a jar containing the interface and the name of the interface class (following the provided examples...).

Whenever I do this I receive an ClassNotFoundException, originally thrown by JarClassLoader.loadClass() (line 88).

I've copied the file to my project and done some testing and I think I've pinpointed the error to line 72:

Code:

String filename = name.replace('.', File.separatorChar) + ".class";

Because I'm on a windows pc the filename is separated by backward slashes (\) in my case.

Further down in the method loadClassData() method the entries are read from the JarFile, using the method jar.getNextJarEntry(). These entries are separated by a forward slash (/) on my pc.

Code:

entry: uk/ac/bath/cs/dataservice/ITest.class
    entry.entry.getName().equals(uk\ac\bath\cs\dataservice\ITest.class): false

Therefore the name comparison in line 130 fails, no classData is returned and the ClassNotFound exception thrown in line 88.

I haven't found any documentation on the format which the getNextJarEntry() method uses so I'm not sure if using File.separatorChar is the problem or actually something else... And ideas?

Cheers,
Ben

]]> Mon, 01 Mar 2010 21:05:15 +0100 Problem using getLog() methods in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=241#241 241@http://www.agentscape.org/forums Thanks, that did it :) Thanks, that did it :)

]]> Fri, 19 Feb 2010 12:23:22 +0100 Problem using getLog() methods in AgentScape : Trouble Shooting http://www.agentscape.org/forums/viewtopic.php?pid=240#240 240@http://www.agentscape.org/forums Hi Ben,the AgentLog class extends from the SimpleLog class, to be found in commons-logging.jarI think adding this to the class path would allow netbeans to recognize the info() method.Of course, regardless of what netbeans shows as errors, the build can probably still be made (ant resolves the dependencies itself from src/lib) Cheers,Reinier Hi Ben,

the AgentLog class extends from the SimpleLog class, to be found in commons-logging.jar
I think adding this to the class path would allow netbeans to recognize the info() method.

Of course, regardless of what netbeans shows as errors, the build can probably still be made (ant resolves the dependencies itself from src/lib)

Cheers,
Reinier

]]> Thu, 18 Feb 2010 20:49:52 +0100