Re: Class loading order
On 27/07/2011 06:19, Anne, Radhakrishna (NSN - IN/Bangalore) wrote: Hello, Can I use virtualWebAppLoader class to meet my requirements..? You might be able to, but please note: 'hot fixes' and 'patches' are not concepts that work well with compiled webapps. If you need to update a webapp, you should release a new version. Distributing instructions for applying updates to individual class files is going to cause you all sorts of support problems. Likewise, applying 'hot fixes' to plugin JARs isn't a good idea. E.g. If there are sequential modifications to a class, each will have to carry all the previous changes. Why not just update the JAR instead? You can also enable the shared classloader in tomcat/conf/catalina.properties. p Regards Krishna -Original Message- From: Anne, Radhakrishna (NSN - IN/Bangalore) Sent: Tuesday, July 26, 2011 2:24 PM To: Tomcat Users List Subject: RE: Class loading order Hello, My web applications is designed to plug-in 3 rd party modules. 3rd party jars and my jars would placed under WEB-INF/libs. In case of bugs, the third party developer may provide hot fixes , which would be placed under WEB-INF/classes usually. I do not want to place their hot fixes under WEB-INF/classes, as they may conflict with my hot fixes and this would create some problems during maintenance. So I was checking the possibility of defining a new location for 3rd party hot fixes. Is there any way to do this..? Regards, Krishna -Original Message- From: ext Pid [mailto:p...@pidster.com] Sent: Tuesday, July 26, 2011 2:15 PM To: Tomcat Users List Subject: Re: Class loading order On 26/07/2011 09:38, Anne, Radhakrishna (NSN - IN/Bangalore) wrote: Hello, I would like to changes the default order look up for class loading, as I understood from the doc, the order of look up is 1) WEB-INF/classes 2) WEB_INF/lib. Now I wanted to change this order and have my own order look up as shown below i.e. 1) /opt/shared/classes 2) WEB-INF/classes 3) WEB_INF/lib. Can someone help me out..? I am using tomcat 6 version. No, the only way to do this is via a custom classloader of your own design. It is probably a bad idea to do this - a webapp's classloader is supposed to load its own classes first. Why can't you include the classes in the webapp? p - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Class loading order
I think that what Anne want is the hot swap of classes ,replace loaded classes with new version in hotfix jars.That might break the security of java,I reckon. am I right ? 2011/7/27 Pid p...@pidster.com On 27/07/2011 06:19, Anne, Radhakrishna (NSN - IN/Bangalore) wrote: Hello, Can I use virtualWebAppLoader class to meet my requirements..? You might be able to, but please note: 'hot fixes' and 'patches' are not concepts that work well with compiled webapps. If you need to update a webapp, you should release a new version. Distributing instructions for applying updates to individual class files is going to cause you all sorts of support problems. Likewise, applying 'hot fixes' to plugin JARs isn't a good idea. E.g. If there are sequential modifications to a class, each will have to carry all the previous changes. Why not just update the JAR instead? You can also enable the shared classloader in tomcat/conf/catalina.properties. p Regards Krishna -Original Message- From: Anne, Radhakrishna (NSN - IN/Bangalore) Sent: Tuesday, July 26, 2011 2:24 PM To: Tomcat Users List Subject: RE: Class loading order Hello, My web applications is designed to plug-in 3 rd party modules. 3rd party jars and my jars would placed under WEB-INF/libs. In case of bugs, the third party developer may provide hot fixes , which would be placed under WEB-INF/classes usually. I do not want to place their hot fixes under WEB-INF/classes, as they may conflict with my hot fixes and this would create some problems during maintenance. So I was checking the possibility of defining a new location for 3rd party hot fixes. Is there any way to do this..? Regards, Krishna -Original Message- From: ext Pid [mailto:p...@pidster.com] Sent: Tuesday, July 26, 2011 2:15 PM To: Tomcat Users List Subject: Re: Class loading order On 26/07/2011 09:38, Anne, Radhakrishna (NSN - IN/Bangalore) wrote: Hello, I would like to changes the default order look up for class loading, as I understood from the doc, the order of look up is 1) WEB-INF/classes 2) WEB_INF/lib. Now I wanted to change this order and have my own order look up as shown below i.e. 1) /opt/shared/classes 2) WEB-INF/classes 3) WEB_INF/lib. Can someone help me out..? I am using tomcat 6 version. No, the only way to do this is via a custom classloader of your own design. It is probably a bad idea to do this - a webapp's classloader is supposed to load its own classes first. Why can't you include the classes in the webapp? p - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org -- Never trust your computer.
RE: Class loading order
Hello, Yes, we will take care of sequential modifications of class during updates, and that is not a problem for us. I have tried changing tomcat/conf/catalina.properties, but that did not work for me.. Regards, Krishna -Original Message- From: ext Pid [mailto:p...@pidster.com] Sent: Wednesday, July 27, 2011 1:12 PM To: Tomcat Users List Subject: Re: Class loading order On 27/07/2011 06:19, Anne, Radhakrishna (NSN - IN/Bangalore) wrote: Hello, Can I use virtualWebAppLoader class to meet my requirements..? You might be able to, but please note: 'hot fixes' and 'patches' are not concepts that work well with compiled webapps. If you need to update a webapp, you should release a new version. Distributing instructions for applying updates to individual class files is going to cause you all sorts of support problems. Likewise, applying 'hot fixes' to plugin JARs isn't a good idea. E.g. If there are sequential modifications to a class, each will have to carry all the previous changes. Why not just update the JAR instead? You can also enable the shared classloader in tomcat/conf/catalina.properties. p Regards Krishna -Original Message- From: Anne, Radhakrishna (NSN - IN/Bangalore) Sent: Tuesday, July 26, 2011 2:24 PM To: Tomcat Users List Subject: RE: Class loading order Hello, My web applications is designed to plug-in 3 rd party modules. 3rd party jars and my jars would placed under WEB-INF/libs. In case of bugs, the third party developer may provide hot fixes , which would be placed under WEB-INF/classes usually. I do not want to place their hot fixes under WEB-INF/classes, as they may conflict with my hot fixes and this would create some problems during maintenance. So I was checking the possibility of defining a new location for 3rd party hot fixes. Is there any way to do this..? Regards, Krishna -Original Message- From: ext Pid [mailto:p...@pidster.com] Sent: Tuesday, July 26, 2011 2:15 PM To: Tomcat Users List Subject: Re: Class loading order On 26/07/2011 09:38, Anne, Radhakrishna (NSN - IN/Bangalore) wrote: Hello, I would like to changes the default order look up for class loading, as I understood from the doc, the order of look up is 1) WEB-INF/classes 2) WEB_INF/lib. Now I wanted to change this order and have my own order look up as shown below i.e. 1) /opt/shared/classes 2) WEB-INF/classes 3) WEB_INF/lib. Can someone help me out..? I am using tomcat 6 version. No, the only way to do this is via a custom classloader of your own design. It is probably a bad idea to do this - a webapp's classloader is supposed to load its own classes first. Why can't you include the classes in the webapp? p - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Class loading order
On 27/07/2011 08:55, Joseph wrote: I think that what Anne want is the hot swap of classes ,replace loaded classes with new version in hotfix jars.That might break the security of java,I reckon. am I right ? If the requirement is 'live' replacement of classes already loaded by the JVM then the OP will definitely need to build a custom classloader. It won't break Java security per se, but it is likely to be error prone. OSGI has some answers for this kind of thing AFAIK, but unaugmented Java + Tomcat won't like it at all. p 2011/7/27 Pid p...@pidster.com On 27/07/2011 06:19, Anne, Radhakrishna (NSN - IN/Bangalore) wrote: Hello, Can I use virtualWebAppLoader class to meet my requirements..? You might be able to, but please note: 'hot fixes' and 'patches' are not concepts that work well with compiled webapps. If you need to update a webapp, you should release a new version. Distributing instructions for applying updates to individual class files is going to cause you all sorts of support problems. Likewise, applying 'hot fixes' to plugin JARs isn't a good idea. E.g. If there are sequential modifications to a class, each will have to carry all the previous changes. Why not just update the JAR instead? You can also enable the shared classloader in tomcat/conf/catalina.properties. p Regards Krishna -Original Message- From: Anne, Radhakrishna (NSN - IN/Bangalore) Sent: Tuesday, July 26, 2011 2:24 PM To: Tomcat Users List Subject: RE: Class loading order Hello, My web applications is designed to plug-in 3 rd party modules. 3rd party jars and my jars would placed under WEB-INF/libs. In case of bugs, the third party developer may provide hot fixes , which would be placed under WEB-INF/classes usually. I do not want to place their hot fixes under WEB-INF/classes, as they may conflict with my hot fixes and this would create some problems during maintenance. So I was checking the possibility of defining a new location for 3rd party hot fixes. Is there any way to do this..? Regards, Krishna -Original Message- From: ext Pid [mailto:p...@pidster.com] Sent: Tuesday, July 26, 2011 2:15 PM To: Tomcat Users List Subject: Re: Class loading order On 26/07/2011 09:38, Anne, Radhakrishna (NSN - IN/Bangalore) wrote: Hello, I would like to changes the default order look up for class loading, as I understood from the doc, the order of look up is 1) WEB-INF/classes 2) WEB_INF/lib. Now I wanted to change this order and have my own order look up as shown below i.e. 1) /opt/shared/classes 2) WEB-INF/classes 3) WEB_INF/lib. Can someone help me out..? I am using tomcat 6 version. No, the only way to do this is via a custom classloader of your own design. It is probably a bad idea to do this - a webapp's classloader is supposed to load its own classes first. Why can't you include the classes in the webapp? p - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: Class loading order
Hello, I would like to changes the default order look up for class loading, as I understood from the doc, the order of look up is 1) WEB-INF/classes 2) WEB_INF/lib. Now I wanted to change this order and have my own order look up as shown below i.e. 1) /opt/shared/classes 2) WEB-INF/classes 3) WEB_INF/lib. Can someone help me out..? I am using tomcat 6 version. Regards,Mailcode: tL3PbjBL Krishna
Re: Class loading order
On 26/07/2011 09:38, Anne, Radhakrishna (NSN - IN/Bangalore) wrote: Hello, I would like to changes the default order look up for class loading, as I understood from the doc, the order of look up is 1)WEB-INF/classes 2)WEB_INF/lib. Now I wanted to change this order and have my own order look up as shown below i.e. 1)/opt/shared/classes 2)WEB-INF/classes 3)WEB_INF/lib. Can someone help me out..? I am using tomcat 6 version. No, the only way to do this is via a custom classloader of your own design. It is probably a bad idea to do this - a webapp's classloader is supposed to load its own classes first. Why can't you include the classes in the webapp? p - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: Class loading order
Hello, My web applications is designed to plug-in 3 rd party modules. 3rd party jars and my jars would placed under WEB-INF/libs. In case of bugs, the third party developer may provide hot fixes , which would be placed under WEB-INF/classes usually. I do not want to place their hot fixes under WEB-INF/classes, as they may conflict with my hot fixes and this would create some problems during maintenance. So I was checking the possibility of defining a new location for 3rd party hot fixes. Is there any way to do this..? Regards, Krishna -Original Message- From: ext Pid [mailto:p...@pidster.com] Sent: Tuesday, July 26, 2011 2:15 PM To: Tomcat Users List Subject: Re: Class loading order On 26/07/2011 09:38, Anne, Radhakrishna (NSN - IN/Bangalore) wrote: Hello, I would like to changes the default order look up for class loading, as I understood from the doc, the order of look up is 1)WEB-INF/classes 2)WEB_INF/lib. Now I wanted to change this order and have my own order look up as shown below i.e. 1)/opt/shared/classes 2)WEB-INF/classes 3)WEB_INF/lib. Can someone help me out..? I am using tomcat 6 version. No, the only way to do this is via a custom classloader of your own design. It is probably a bad idea to do this - a webapp's classloader is supposed to load its own classes first. Why can't you include the classes in the webapp? p - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
RE: Class loading order
Hello, Can I use virtualWebAppLoader class to meet my requirements..? Regards Krishna -Original Message- From: Anne, Radhakrishna (NSN - IN/Bangalore) Sent: Tuesday, July 26, 2011 2:24 PM To: Tomcat Users List Subject: RE: Class loading order Hello, My web applications is designed to plug-in 3 rd party modules. 3rd party jars and my jars would placed under WEB-INF/libs. In case of bugs, the third party developer may provide hot fixes , which would be placed under WEB-INF/classes usually. I do not want to place their hot fixes under WEB-INF/classes, as they may conflict with my hot fixes and this would create some problems during maintenance. So I was checking the possibility of defining a new location for 3rd party hot fixes. Is there any way to do this..? Regards, Krishna -Original Message- From: ext Pid [mailto:p...@pidster.com] Sent: Tuesday, July 26, 2011 2:15 PM To: Tomcat Users List Subject: Re: Class loading order On 26/07/2011 09:38, Anne, Radhakrishna (NSN - IN/Bangalore) wrote: Hello, I would like to changes the default order look up for class loading, as I understood from the doc, the order of look up is 1)WEB-INF/classes 2)WEB_INF/lib. Now I wanted to change this order and have my own order look up as shown below i.e. 1)/opt/shared/classes 2)WEB-INF/classes 3)WEB_INF/lib. Can someone help me out..? I am using tomcat 6 version. No, the only way to do this is via a custom classloader of your own design. It is probably a bad idea to do this - a webapp's classloader is supposed to load its own classes first. Why can't you include the classes in the webapp? p - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
