Problems with Context/
A discussion regarding the use of the Context/ element, within server.xml and $CATALINA_BASE/conf/[enginename]/[hostname]/, grew from a thread with subject Problem with JNDI environment entry resources: http://marc.info/?l=tomcat-userm=122045686313688w=2 In that thread the question seemed to boil down to: Can, or should, a web application's war file name or exploded directory name be allowed to differ to the the context path? This problem arose for me out of an attempt to use a context file: $CATALINA_BASE/conf/[enginename]/[hostname]/ROOT.xml with the following contents: Context docBase=appname.war / On my reading of http://tomcat.apache.org/tomcat-6.0-doc/config/context.html this is valid configuration. However, the app at docBase didn't deploy as the default (ROOT) app, but it does if the Context/ element is placed in server.xml: Context docBase=appname.war path= / Is it the docs, the code, or my understanding, that is out when I try to make a web app the default app using a file, $CATALINA_BASE/conf/[enginename]/[hostname]/ROOT.xml? If the issue is one of code or docs, then I'm happy to do what I can to resolve that. Thanks, Paul. - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Problems with Context/
Paul Pepper wrote: A discussion regarding the use of the Context/ element, within server.xml and $CATALINA_BASE/conf/[enginename]/[hostname]/, grew from a thread with subject Problem with JNDI environment entry resources: http://marc.info/?l=tomcat-userm=122045686313688w=2 In that thread the question seemed to boil down to: Can, or should, a web application's war file name or exploded directory name be allowed to differ to the the context path? This problem arose for me out of an attempt to use a context file: $CATALINA_BASE/conf/[enginename]/[hostname]/ROOT.xml with the following contents: Context docBase=appname.war / At best, you will get double deployment. If webapps/ROOT already exists it is anybody's guess what will happen. Is it the docs, the code, or my understanding, that is out when I try to make a web app the default app using a file, $CATALINA_BASE/conf/[enginename]/[hostname]/ROOT.xml? The docs could make clearer that an docBase should only ever be used if outside the appBase. Mark - To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Problems Using Context Loader
No, that is not a Tomcat problem... it's a specific application problem... I saw some people complaining about the same things in applications similar to mine. The big whole problem with my application is the framework usage: Hibernate and Struts... My guess is that hibernate is not finalizing normally (i done some tests restarting the context using only struts and garbage collecting and checking the amount of free memory)... cause when I restart the context about 4 times using hibernate and struts there is no more free memory neither memory to allocate. It ends with a Heap space error. Every time a new class is compiled during development the context must be restarted to update the class reference, so now we have a problem. My way out is to make a classloader to monitor these classes in classes folder and auto-update the reference... Wish me luck ;-) I will take a look at your idea... but seems you are not trying to reload the classes references. - Segue mensagem original! - De: Sriram Narayanan [EMAIL PROTECTED] Data: Thu, 12 Jan 2006 01:59:21 +0530 Para: Tomcat Users List users@tomcat.apache.org Assunto: Re: Problems Using Context Loader On 1/11/06, Michel Costa [EMAIL PROTECTED] wrote: Hi everyone, I am trying to create a ClassLoader for my application so then I will not have to reload all the hibernate and struts when a new class is compiled. Could you please explain why this is a problem ? Is the startup time an issue ? Then my problems started: I do not know where to put my special ClassLoader. I got lots of classcast exceptions until I found that a instance of org.apache.catalina.loader.WebappClassLoader. So far so good, just extended my class and apache can't find org.apache.catalina.loader.WebappClassLoader. I'd taken another approach. See http://issues.apache.org/bugzilla/show_bug.cgi?id=38223 Now I have a java.lang.ClassNotFoundException: org.apache.catalina.loader.WebappClassLoader I think the error is just because I put my classloader in the wrong place (which is CATALINA_HOME/common/classes) but i could not avoid this common folder... Before this one, I tried webapps/MYAPP/WEB-INF/classes but java didnt found my class. My guess is something about the ClassLoader hierarchy and visibility of the classes... You place your class at CATALINA_HOME/server/classes. See the bug report that I've filed for information on how I used my own Classloader. -- Sriram - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Problems Using Context Loader
On 1/12/06, Michel Costa [EMAIL PROTECTED] wrote: No, that is not a Tomcat problem... it's a specific application problem... I saw some people complaining about the same things in applications similar to mine. By No, that is not a Tomcat problem..., I believe you're saying that there's no problem related to startup etc. Ack on the statement that you're talking about an application specific problem. The big whole problem with my application is the framework usage: Hibernate and Struts... My guess is that hibernate is not finalizing normally (i done some tests restarting the context using only struts and garbage collecting and checking the amount of free memory)... cause when I restart the context about 4 times using hibernate and struts there is no more free memory neither memory to allocate. It ends with a Heap space error. Ack. So you're placing hibernate in the Context's WEB-INF/lib folder ? I haven't used Hibernate yet, but will do so to understand this issue. Every time a new class is compiled during development the context must be restarted to update the class reference, so now we have a problem. My way out is to make a classloader to monitor these classes in classes folder and auto-update the reference... Is this what you want ? a) Hibernate etc are loaded just once. b) Your apps' classes are monitored and when ever they change, a fresh classloader is instantiated. c) At this time, Hibernate etc are not to be reloaded. d) Hibernate and Struts and anyone else should continue to to have access to the latest classes. I see a problem with Hibernate having a reference to the older classes (perhaps in objects that are cached, etc. I don't know for sure, I'm just speculating here). This would be an interesting problem to solve. If you don't get this right, then let me know, I'd like to help. I'm interesting in solving this classloader requirement as well - it'll be a good exercise for the mind :) Wish me luck ;-) Best of luck :) I will take a look at your idea... but seems you are not trying to reload the classes references. Correct. It was just something I put together late at night. I'm considering adding stuff like monitoring for changes in the classes mentioned in these paths, etc. I'll look into this. Let me know if you'd like to see some feature. -- Sriram - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Problems Using Context Loader
The major problem is not about putting hibernate in the context's lib folder,
but as you may know, hibernate does some mapping stuff, which means it reads a
bunch of .hbm.xml files into memory, connects and validate these mappings
everytime the context gets reloaded, and depending on how much mappings you
use, a bigger problem you have, about the loading time... It takes about 30
seconds for each reload and a maximum of 4 reloads.
The difficult part of it is to make my custom ClassLoader access the webapp's
classloader... because it must be placed in the server folder and because of
this, it is not in the webapp's classloader hiearchy.
Mine implementation speed is a little slow, i am just trying to load the
classes primarly, with no errors, and then is time to think about reloading...
I think it would be much easier if I could monitorate these files directly from
the WebApp's classloader, but this means modify tomcat's distribution.
This is all I have done so far:
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.security.AccessControlException;
import java.util.Hashtable;
import org.apache.catalina.loader.WebappClassLoader;
public class DeployerClassLoader extends WebappClassLoader {
private static HashtableString, Class classes = new HashtableString,
Class();
private String rootFolder;
public DeployerClassLoader(ClassLoader parent) {
super(parent);
init();
showTree(this, );
}
private String showTree(ClassLoader cls, String pre) {
if (cls.getParent() != null) {
pre = showTree(cls.getParent(), pre);
}
System.out.println(pre + - + cls.getClass().toString());
return pre + ;
}
private void init() {
System.out.println(!!!calling init!!!);
rootFolder = /opt/tomcat/webapps/AppRoot/WEB-INF/classes/;
}
private byte[] findInPath(String name) {
String path = name.replaceAll(\\., /);
File fClass = new File(rootFolder + path + .class);
if (fClass.exists()) {
try {
FileInputStream fStream = new
FileInputStream(fClass);
byte[] all = new byte[(int) fClass.length()];
fStream.read(all);
return all;
} catch (FileNotFoundException e) {
return null;
} catch (IOException e) {
return null;
}
}
return null;
}
protected Class findLoadedClass0(String name) {
System.out.println(findLoaded: + name);
if (name.startsWith(br.com.agem.sige)) {
// se encontrar chamar defineClass(String name, byte[]
b, int off,
// int len)
if (classes.get(name) != null)
return classes.get(name);
}
return super.findLoadedClass0(name);
}
protected Class findClassInternal(String name) throws
ClassNotFoundException {
byte[] data = findInPath(name);
if (data != null) {
synchronized (this) {
Class c = defineClass(name, data, 0, data.length);
classes.put(name, c);
return c;
}
}
throw new ClassNotFoundException(name);
}
public Class findClass(String name) throws ClassNotFoundException {
if (!started) throw new ClassNotFoundException(name);
// (1) Permission to define this class when using a SecurityManager
if (securityManager != null) {
int i = name.lastIndexOf('.');
if (i = 0) {
try {
securityManager.checkPackageDefinition(name.substring(0,i));
} catch (Exception se) {
throw new ClassNotFoundException(name, se);
}
}
}
// Ask our superclass to locate this class, if possible
// (throws ClassNotFoundException if it is not found)
Class clazz = null;
try {
clazz = findClassInternal(name);
} catch(ClassNotFoundException cnfe) {
} catch(AccessControlException ace) {
throw new ClassNotFoundException(name, ace);
}
if (clazz == null) try {
clazz = super.findClass(name);
} catch(AccessControlException ace) {
throw new ClassNotFoundException(name, ace);
}
if (clazz == null) throw new ClassNotFoundException(name);
return clazz;
}
}
Problems Using Context Loader
Hi everyone, I am trying to create a ClassLoader for my application so then I will not have to reload all the hibernate and struts when a new class is compiled. Then my problems started: I do not know where to put my special ClassLoader. I got lots of classcast exceptions until I found that a instance of org.apache.catalina.loader.WebappClassLoader. So far so good, just extended my class and apache can't find org.apache.catalina.loader.WebappClassLoader. Now I have a java.lang.ClassNotFoundException: org.apache.catalina.loader.WebappClassLoader I think the error is just because I put my classloader in the wrong place (which is CATALINA_HOME/common/classes) but i could not avoid this common folder... Before this one, I tried webapps/MYAPP/WEB-INF/classes but java didnt found my class. My guess is something about the ClassLoader hierarchy and visibility of the classes... Well... here goes some info: I am runing catalina on a linux workstation, ubuntu. my app's context.xml: ?xml version=1.0 encoding=UTF-8? Context Loader loaderClass=DeployerClassLoader delegate=false reloadable=false/ WatchedResourceWEB-INF/web.xml/WatchedResource /Context the tomcat output: 11/01/2006 10:56:33 org.apache.catalina.loader.WebappLoader start SEVERE: LifecycleException java.lang.NoClassDefFoundError: org/apache/catalina/loader/WebappClassLoader at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:620) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124) at java.net.URLClassLoader.defineClass(URLClassLoader.java:260) at java.net.URLClassLoader.access$100(URLClassLoader.java:56) at java.net.URLClassLoader$1.run(URLClassLoader.java:195) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:188) at java.lang.ClassLoader.loadClass(ClassLoader.java:306) at java.lang.ClassLoader.loadClass(ClassLoader.java:299) at java.lang.ClassLoader.loadClass(ClassLoader.java:251) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:164) at org.apache.catalina.loader.WebappLoader.createClassLoader(WebappLoader.java:769) at org.apache.catalina.loader.WebappLoader.start(WebappLoader.java:638) at org.apache.catalina.core.StandardContext.start(StandardContext.java:4076) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:759) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:739) at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:524) at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:910) at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:873) at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:474) at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1118) at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:310) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1020) at org.apache.catalina.core.StandardHost.start(StandardHost.java:718) at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1012) at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:442) at org.apache.catalina.core.StandardService.start(StandardService.java:450) at org.apache.catalina.core.StandardServer.start(StandardServer.java:700) at org.apache.catalina.startup.Catalina.start(Catalina.java:551) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:585) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:275) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413) 11/01/2006 10:56:33 org.apache.catalina.core.ContainerBase addChildInternal SEVERE: ContainerBase.addChild: start: LifecycleException: start: : java.lang.NoClassDefFoundError: org/apache/catalina/loader/WebappClassLoader at org.apache.catalina.loader.WebappLoader.start(WebappLoader.java:675) at org.apache.catalina.core.StandardContext.start(StandardContext.java:4076) at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:759) at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:739) at
Re: Problems Using Context Loader
On 1/11/06, Michel Costa [EMAIL PROTECTED] wrote: Hi everyone, I am trying to create a ClassLoader for my application so then I will not have to reload all the hibernate and struts when a new class is compiled. Could you please explain why this is a problem ? Is the startup time an issue ? Then my problems started: I do not know where to put my special ClassLoader. I got lots of classcast exceptions until I found that a instance of org.apache.catalina.loader.WebappClassLoader. So far so good, just extended my class and apache can't find org.apache.catalina.loader.WebappClassLoader. I'd taken another approach. See http://issues.apache.org/bugzilla/show_bug.cgi?id=38223 Now I have a java.lang.ClassNotFoundException: org.apache.catalina.loader.WebappClassLoader I think the error is just because I put my classloader in the wrong place (which is CATALINA_HOME/common/classes) but i could not avoid this common folder... Before this one, I tried webapps/MYAPP/WEB-INF/classes but java didnt found my class. My guess is something about the ClassLoader hierarchy and visibility of the classes... You place your class at CATALINA_HOME/server/classes. See the bug report that I've filed for information on how I used my own Classloader. -- Sriram - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
