Re: 2 Apps, 1 Tomcat
Mazur, Tomcat internally has ways of associating classes to which web-application they belong to. There are classes of three kinds that get loaded when Tomcat gets loaded:- 1. Tomcat internal classes - These are the actual classes loaded by default class loader of the JVM. 2. Common classes - These are classes that are shared across web-applications/Contexts. These are loaded using a custom class loader which comes as a part of Tomcat. 3. Web-Application classes - These are loaded using a WebAppClassLoader which takes care of associating with the correct web-app. A class of one web-app will not be accessble by another web-app.There are ways to enabling this in Tomcat but not all servlet engines support them. The class loading sequence will be similar to the following:- 1. Look in the WEB-INF\lib and WEB-INF\classes 2. If present load it from there for the web-application that's trying to access it. 3. If not go to CLASSPATH and see if the Class is available. However you getting error on app2.classes while you are importing only app1.classes is quite a weird error. Check out if you have any references to app2.classes in any of your beans that u use. I have deployed the same classes with different properties in different web-applications and have not had a single problem so far. In fact if this is not supported our companys' primary product goes for a toss :) Anand At 08:46 AM 10/21/2001 -0700, you wrote: Thanks for responding, Anand. Ok, so are you suggesting that having the jar files in the tomcat_home/lib directory may be messing things up and I should have app1.jar and app2.jar in the tomcat_home/webapps/examples/WEB-INF/classes directory? And then each of the jar files should be filled only with classes containing the header package app1.classes line, or package app2.classes line (depending on what they belong to)? I guess I am not sure how Tomcat knows that a certain class is part of a certain app. I mean, as far as Tomcat is concerned, both app1.jar and app2.jar could both be part of the same application, and when it finds Products.class in app1.jar having the header package app1.classes, but my jsp or other class is calling for import app2.classes.Product, I am still going to get an error like I am getting right now, won't I? Thanks, Rob Anand B N wrote: Mazur, There is a way of using the same classes in two different web-apps in tomcat. Try making individual JARs of the respective classes for app#1 and app#2 and put them in the corresponding WEB-INF/lib or put the classes for each of the web-app in the respective WEB-INF/classes. and remove the jar that u place in TOMCAT_HOME/lib/ Tomcat has an web-app class loader that loads classes based on which web-application it belongs to. So even if you have the same Class(same package) in two different web-app the classes are loaded twice and this is how not only tomcat bu all servlet engines should work. In tomcat parlance each of these web-apps are called Context and Tomcat always loads a new copy ofthe class if it belongs to a different web-app/Context. Anand At 09:24 AM 10/20/2001 -0700, you wrote: Sort of longhoping more detail helps... Tomcat 3.2.3, Apache 1.3.14, RedHat 6.2 I have a problem with class files with the same name being used by two different apps, both web-browser-based. I have 2 applications running on the same instance of Tomcat (low traffic). They both have some class files that have identical names, but the contents are be mildly different. This seems to be a problem when I use one app, then go to the other. For example, if app #1 has a class object called Product.class, and then I go to app #2 that also uses an object called Product, but it has different properties/methods, I get an error because my browser (I *think* my browser is the culprit) is looking for the first Product object it already used from app#1. It is obvious I have a configuration problem. But I'm not sure what the proper resolution is. Here is what I have: I used to have only one app running, and therefore put all my class files into webapps/examples/WEB-INF/classes. These classes would be called from other classes or JSP's with: import Product; -or- %@ page import = Product %; All was great. Then I added an application that also uses an object called Product, but it is different. I elected to put all classes for this app in a jar file, and put the jar in my tomcat_home/lib directory. All the classes have the line at the top of the source: package app2/classes; ...and I have the jar file properly set to have those direcotries inside. I call the classes in here from other classes or jsp's with: import app2.classes.Product; -or- %@ page import = app2.classes.Product; I thought the prefix would be enough to separate the two Product classes, but they are not. Note that: if I
Re: admin context
David, As regards to where to define your users here what you have to do :- tomcat-users.xml defines a set of roles and users with passwords. Here's a snippet:- tomcat-users user name=tomcat password=tomcat roles=tomcat / user name=role1 password=tomcat roles=role1 / user name=both password=tomcat roles=tomcat,role1 / /tomcat-users What is done normally for the admin context is that the role of admin is defined in the security-constraint of the web.xml of the admin context. All you have to do is add a user with suitable userid and password with the same roles as admin. i.e. add the follwing line to your tomcat-users.xml user name=admin password=admin roles=admin / Then the userid/password is admin/admin The server.xml explains clearly what the trusted attribute is supposed to mean. Here's what it says:- trusted=false (trusted allows you to access tomcat internal objects with FacadeManager ) Hope that helps Anand At 11:33 AM 10/22/2001 +0200, you wrote: Hello there, I tried following the instructions of how to manage the admin context in Tomcat 3.2.3, yet could not understand what to do... what is the trusted attribute in the Context tag in server.xml? where do I need to define users? in tomcat-users.xml? which role does the admin have? Please link me to a clear explanation page, or list the actions I should take... :o) Thanks in advance! David.
Re: 2 Apps, 1 Tomcat
Mazur, There is a way of using the same classes in two different web-apps in tomcat. Try making individual JARs of the respective classes for app#1 and app#2 and put them in the corresponding WEB-INF/lib or put the classes for each of the web-app in the respective WEB-INF/classes. and remove the jar that u place in TOMCAT_HOME/lib/ Tomcat has an web-app class loader that loads classes based on which web-application it belongs to. So even if you have the same Class(same package) in two different web-app the classes are loaded twice and this is how not only tomcat bu all servlet engines should work. In tomcat parlance each of these web-apps are called Context and Tomcat always loads a new copy ofthe class if it belongs to a different web-app/Context. Anand At 09:24 AM 10/20/2001 -0700, you wrote: Sort of longhoping more detail helps... Tomcat 3.2.3, Apache 1.3.14, RedHat 6.2 I have a problem with class files with the same name being used by two different apps, both web-browser-based. I have 2 applications running on the same instance of Tomcat (low traffic). They both have some class files that have identical names, but the contents are be mildly different. This seems to be a problem when I use one app, then go to the other. For example, if app #1 has a class object called Product.class, and then I go to app #2 that also uses an object called Product, but it has different properties/methods, I get an error because my browser (I *think* my browser is the culprit) is looking for the first Product object it already used from app#1. It is obvious I have a configuration problem. But I'm not sure what the proper resolution is. Here is what I have: I used to have only one app running, and therefore put all my class files into webapps/examples/WEB-INF/classes. These classes would be called from other classes or JSP's with: import Product; -or- %@ page import = Product %; All was great. Then I added an application that also uses an object called Product, but it is different. I elected to put all classes for this app in a jar file, and put the jar in my tomcat_home/lib directory. All the classes have the line at the top of the source: package app2/classes; ...and I have the jar file properly set to have those direcotries inside. I call the classes in here from other classes or jsp's with: import app2.classes.Product; -or- %@ page import = app2.classes.Product; I thought the prefix would be enough to separate the two Product classes, but they are not. Note that: if I run one app, or the other app only, they work great. But if I go from one app to another without first closing my browser and clearing cache, I get an error saying there is an error with app2.classes.Product...when I am using app#1 and it should only be using Product from app#1, not app2.classes.Product. I can certainly see one solution: Make sure ALL classes have unique names, even if they are from separate apps. But there must be a better way, or something I am doing wrong. How do you guys set up 2 apps on one Tomcat instance, when disimilar objects have the same name? Thanks, Rob Mazur p.s. I hopelessly looked for subject like this in the archive, but couldn't find any.
Re: No one answering my question (security realted problem)
Sukhwinder, I've faced this problem before. It's got something to do with where your JAR's are placed in the classpath. If the class throwing this exception is somewhere inside tomcat's internal classes (webserver.jar) then move it to a place other than the default /lib folder and inclde it in the class path. I'm not sure if that answered your question but try it out and also search on the net for Sealing violation. I digged it out of the archives and the reply from Craig was a solution similar to this which worked for me Anand At 02:14 PM 9/5/01 -0700, you wrote: Hello, This is the third time I am sending email. No one is replying. I have downloaded tomcat version 3.2.3 source code and compiled it on my windows 95 machine with Sun JDk 1.3.1. I also had to download JSSE because there was no option to compile without ssl support. If these classes are not in classpath then source doesn't compile. My problem is when after compiling distribution when I try to start tomcat following errors is produced: /// FATAL Configuration error: java.lang.SecurityException: sealing violation .. .. I have followed that steps provided in SSL howto about making entry in java security file and using keytool. For password it is written that password can be changeit but when keytool asks about alias tomcat password what should be entered. (i.e. what is the tomcat admin password). Please help me in solving above problem because I am unable to start tomcat. Is there any option to compile tomcat without ssl support? Sukhwinder Singh ___ Send a cool gift with your E-Card http://www.bluemountain.com/giftcenter/
Re: Is there a way to get the docBase property from within a servlet?
If you are not using WARs and using a folder for your web application then try :- ServletContext tContext = request.getServletContext(); tContext.getRealPath(/); Not sure if it works always but it works and I guess most servlet engines also do function and retunr the docbase property this way. Anand At 03:00 PM 9/5/01 -0700, you wrote: On Wed, 5 Sep 2001, Rick Mann wrote: Date: Wed, 05 Sep 2001 14:38:07 -0700 From: Rick Mann [EMAIL PROTECTED] To: tomcat user jakarta.apache.org [EMAIL PROTECTED], Craig R. McClanahan [EMAIL PROTECTED] Subject: Re: Is there a way to get the docBase property from within a servlet? on 9/1/01 9:48 PM, Craig R. McClanahan at [EMAIL PROTECTED] wrote: Is there a Servlet spec-compliant way to get the webapp's directory's path programmatically, from within a servlet? No. Something like calling ServletConfig.getInitParameter(docBase), but something that's standard, and that does not require me to specify the path explicitly in a configuration file? You are starting from an incorect assumption, that there *is* such a thing as a portable directory path to a web application. It is entirely legal for a servlet container to run a web application directly from a WAR file (in which case there is no expanded directory), or by storing its static resources in some other sort of structure (such as being BLOB objects in a database). Okay. I get that. How does one access a resource, then, whether it's a file in a directory or a file in a WAR file? For example, we have properties files that specify certain things for our web app. Currently, I provide a full path, from root, to this file as an init param to a servlet that gets loaded at context startup. I'd like to be able to refer to this file relative to the web app's directory (or within the web app's) .WAR file. Can you tell me how I'd go about doing this, or what concepts to search for in the documentation to answer this question? The API calls for this are ServletContext.getResource() and ServletContext.getResourcesAsStream(). The path you specify is context relative, and must start with a slash (/) character. Details are in the servlet specification, available at: http://java.sun.com/products/servlet/download.html For example, let's assume you wanted to parse the web app deployment descriptor for your application. You can access it like this: InputStream is = getServletContext().getResourceAsStream(/WEB-INF/web.xml); The /WEB-INF directory is a good place to put resource files like this, because the servlet container will refuse to serve them in response to a direct request from a client. Plus, this call will work no matter how your servlet container deploys your application (in a directory, in a WAR file, or whatever). It also doesn't matter what context path your app ends up with, because the path is only relative to the context. In Servlet 2.3 (i.e. Tomcat 4.0), a new call was added that acts like the list() method of the java.io.File class. For instance, to see the names of all the resources in the /WEB-INF directory, you can say: Set paths = getServletContext().getResourcePaths(/WEB-INF); and process all of them. Tomcat 4 uses this, for example, to do directory listings when there is no welcome file in the selected directory. As always, thanks for your help, Roderick Mann rmann @ latencyzero.com.sansspam Craig
Tomcat 4 :Weird probelms
Hi,
I'm still stuck with my Classes problem in tomcat 4.
As I mentioned earlier the whole thing works fine in a IDE environment like
JBuilder but when I make them jars and put them in a standalone Tomcat 4
envrn it doesn't work.
Here's what I am doing:-
I have a JSP that invokes a method in a JavaBean which inturns contacts a
Singleton class to get handles on Deployer object to get all available
contexts. Here's the code snippet:-
1.Context context;
2.Deployer deployer = TomcatManager.getSharedInstance().getDeployer();
3. System.out.println(deployer);
4. String contextPaths[] = deployer.findDeployedApps();
5. casInstanceList = new Array();
6. response = new ResponseObject();
7. for (int i = 0; i contextPaths.length; i++) {
8. context =
TomcatManager.getSharedInstance().getDeployer().findDeployedApp(contextPaths[i]);
9. casInstanceList.add(context);
10. }
Here TomcatManager get's initialized by a Servlet[which implements the
ContainerServlet interface] on startup.
Sequence of Events:-
On startup
1. Servlet intializes and set's the reference of Tomcat Maanger's Deployer
and other objects
From the webapp -
2. JSP is called and it invokes a JavaBean that invokes method on
TomcatManager to obtain the Deployer reference
3. deployer.finDeployedApps() and now the expcetion is thrown.
As I told earlier I tried the following:-
1. Since my Javabean uses Deployer and Context classes I put them also in
common/classes aprt from them being a part of catalina.jar. I get a linkage
error(loader constraints violated)
2. I remove these and it says class not found
That's the whole picture and I'm not sure if I'm getting the solution as
mentioned but Craig earlier.
Thanks
Anand
On doing further research I realized that the Exception is being thrown
the line 4 of the aboive snippet. It;s able to access the Deployer object
and all that but it fails on this line.
Re: Tomcat 4 help
Craig,
Thanks for the input but let's say I have a situation wherein my web app
classes are to use a static class that has references of the Catalina
internals(like Deployer,Context) etc. should I come to a conclusion that
it is impossible a,s that's exactly what I'm doing with the application
that I am writing.
As you had suggested my Container servlet is in the server/lib folder and
my javabeans and other classes that the JSPs use in the common/lib folder.
Here's a method in a JavaBean that's called from one of the JSPs to list
available contexts
public boolean service()
{
try{
String contextPaths[] =
TomcatManager.getSharedInstance().getDeployer().findDeployedApps();
Context context;
casInstanceList = new Array();
response = new ResponseObject();
for (int i = 0; i contextPaths.length; i++) {
context =
TomcatManager.getSharedInstance().getDeployer().findDeployedApp(contextPaths[i]);
casInstanceList.add(context);
}
...
..
}
Here TomcatManager is the static class that get's it's Deployer and Wrapper
instance set by the Container Servlet on initialization.
Though the task of listing context is a job done by the Manager servlet I
would like to do more than that and therefore thought if I had the
reference to Deployer object I would have better control.
The other thing is if I use a IDE like JBuilder this works perfectly fine
and my application has no problems like those mentioned earlier.
Here's my folder structure:-
/catalina
/common
/lib
- casadmin.jar - JAR containing all Javabeans used by my
JSPs/Webapp
/server
/lib
- catalina.jar - This contains my Container Servlet also
/webapp
/casadmin
- JSPs that use the Javabeans found in casadmin.jar
Hope that gives a better picture of what I'm trouble shooting.
Thanks
Anand
At 08:35 AM 8/27/01 -0700, you wrote:
Moving catalina.jar is pretty much guaranteed to break things, as you
found out. It's placed where it is for fundamental architectural reasons.
The solution is to do what I described earlier:
* Put your Container servlet, and any other class that needs
access to Catalina internals in /servlet/classes or /serv/et/lib/*.jar.
* Put classes that need to be visbile both to your Container servlet
*and* to web apps in /common/classes or /common/lib/*.jar.
Under no circumstances will any class loaded from a web app class loader
be able to access the Catalina internal stuff. That is why, for example,
the Manager webapp is designed the way that it is -- all requests are done
via HTTP instead of method calls.
(By the way, you could do the same thing by having your admin servlet use
HttpURLConnection to perform the actual deploy and undeploy operations via
ManagerServlet ...)
Craig
On Mon, 27 Aug 2001, Anand B N wrote:
Date: Mon, 27 Aug 2001 19:18:02 +0530
From: Anand B N [EMAIL PROTECTED]
Reply-To: [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Subject: Tomcat 4 help
Ok here's my problem:-
I have a Singleton class that gets instantiated while the Servlet(a
container servlet) initializes and in my web application I have JSPs with
Javabeans which then use the Singleton class(called TomcatManager) to get
handles on the Wrapper and Deployer objects so that I can control my
web-aplications.
The need here is to contol/administer web applications from a single point
and we wanted to have more control on adminstering the webapp but
automatically copying JARs required etc which the default Admin would
not do.
So here's what I did:-
I took the catalina.jar that comes in CATALINA_HOME/server/lib and copied
it on to CATALINA_HOME/comman/lib.
And here's the exception that I get from the Java bean that's trying to use
the Deployer class:-
java.lang.LinkageError: Class org/apache/catalina/Context violates loader
constraints
at java.lang.ClassLoader.defineClass0(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:486)
at
java.security.SecureClassLoader.defineClass(SecureClassLoader.java:111)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:248)
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
org.apache.catalina.loader.StandardClassLoader.findClass(StandardClassLoader.java:670)
at
org.apache.catalina.loader.StandardClassLoader.loadClass(StandardClassLoader.java:1088)
at
org.apache.catalina.loader.StandardClassLoader.loadClass(StandardClassLoader.java:987)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:313)
at java.lang.Class.forName0(Native Method
Re: internal server error
Scott, I may be wrong but here's what I think with respect to your problems:- Question 1 : - I really don't know :) Question 2: - Though u have mentioned auto reload to true try the follwing:- Make a new Context entry in the Server.xml with your application and set the reload value to true and see of you observations repeat. We had done a similar observation and it defaults to auto-reload=false if u don't mention it explicitly ion server.xml Question 3: Tomcat's web applications are loaded using an adaptive /web app class loader but it too is a class loader. So once a class is laoded by the class loader it wont load it again until the class has changed( as per your previous question) so removing your classes would not probably affect the Classes. Hope that helps Anand At 08:23 AM 8/28/01 -0400, you wrote: I have a question that hopefully someone on this list can help with. I use the startup.sh and shutdown.sh scripts to start and stop tomcat. If i stop tomcat and then bring it back up and go and try to view a servlet I get an internal server error from apache, like tomcat really isnt up yet or something. But if i then hit refresh on my brower like 7 or 8 times tomcat will start responding like normal. I saw a message on the same topic of this in the mail archives but I didnt see a definite answer. Anyone know why this is? And is there any way to stop this? Second question is about auto reloading. I use ant to create my war files so they are of the standard directory layout. After tomcat starts and unpacks the war I should be able to copy recompiled classes into the MyProject/WEB-INF/classes directory and have tomcat auto reload (server.xml says that auto reload is default to true ) This works most of the time. But sometimes i swear it wont reload my servlet until i stop tomcat, remove the unpacked war directory and restart tomcat. This doesn't make any sense to me? Also one last semi related question. Can someone tell me how tomcat decides what servlets to cache in memory? If it is really auto reloaded servlets, if i delete all my class files i shouldnt be able to get to any servlets correct? But i have deleted all my class files and still can get to certain servlets in my web app. So how does tomcat choose what servlets to cache or not? Any and all information that can help with these three questions would be greatly apprecaited. Thanks in advance. Scott Knight
Tomcat 4 help
Ok here's my problem:- I have a Singleton class that gets instantiated while the Servlet(a container servlet) initializes and in my web application I have JSPs with Javabeans which then use the Singleton class(called TomcatManager) to get handles on the Wrapper and Deployer objects so that I can control my web-aplications. The need here is to contol/administer web applications from a single point and we wanted to have more control on adminstering the webapp but automatically copying JARs required etc which the default Admin would not do. So here's what I did:- I took the catalina.jar that comes in CATALINA_HOME/server/lib and copied it on to CATALINA_HOME/comman/lib. And here's the exception that I get from the Java bean that's trying to use the Deployer class:- java.lang.LinkageError: Class org/apache/catalina/Context violates loader constraints at java.lang.ClassLoader.defineClass0(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:486) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:111) at java.net.URLClassLoader.defineClass(URLClassLoader.java:248) 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 org.apache.catalina.loader.StandardClassLoader.findClass(StandardClassLoader.java:670) at org.apache.catalina.loader.StandardClassLoader.loadClass(StandardClassLoader.java:1088) at org.apache.catalina.loader.StandardClassLoader.loadClass(StandardClassLoader.java:987) at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:313) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:120) at com.lbi.cas.deployment.handlers.ListCASHandler.init(ListCASHandler.java:27) at java.lang.Class.newInstance0(Native Method) at java.lang.Class.newInstance(Class.java:237) at com.lbi.cas.deployment.components.RequestManager.getRequestHandler(RequestManager.java:70) at org.apache.jsp._0002fjsp_0002fc3_0005fcas_0005flist_jsp._jspService(_0002fjsp_0002fc3_0005fcas_0005flist_jsp.java:90) If I'm right this is sometihng to do with dependencies of the classes. I'm not sure where I'm going wrong. Anand
Help with Tomcat4
Hi, I'm using experimenting with Tomcat4 and I did the following:- I wrote a servlet that implements the ContainerServlet[Obviosuly in the org.apache.catalina.servlets package] . Now I have a set of JSPs which in turn use a set of Java beans whcih in turn use this Servlet for getting hol of information on Context etc. However I am facing the follwing problem:- In my Java bean if I import org.apache.catalina.Deployer it's not able to find the class in my classpath and throws a ClassNotFoundException. I found this problem very weird as these are the classes in the standard JAR that comes with Tomcat 4. Could someone please explain this to me? Anand Associate,RD, Digital Think
