Author Topic: tomcat and ubuntu (Read 578 times)

p2 · « **on:** December 01, 2016, 04:06:58 pm »

I tried to setup a Java Servlet on a Tomcat-8 on Ubuntu server and ran in thousands of problems. Maybe you can learn from them

Even if not... I stilll got +1 post (quantity, yaay) ^^
I am referring to tomcat8 that was NOT installed using the official repository. If oyu used it (recommended) many things (like paths) will be different.

How to solve stupid problems with servlets on tomcat:

to see if your tomcat is working, jost go on yourdomain.com:8080/
you should then see the welcome screen of tomcat:

(click to show/hide)

if you're NOT seeing this, you should check if your tomcat is running.
To do this go to the terminal and enter:

Code: [Select]

sudo systemctl restart tomcat
systemctl status tomcat

you should see something like this:

to go back press CTRL + C

(click to show/hide)

If you see this but the site isn't working, that probably means your permission aren't set correctly.
You should make sure the owners/groups are set correctly.
To set them, enter this:

Code: [Select]

sudo chown tomcat:tomcat /opt/tomcat/webapps/MYFILE.WAR
sudo chown tomcat:tomcat /opt/tomcat/webapps/
sudo systemctl restart tomcat

You should put in the correct name for your WAR file (your servlet).
Then you should again check if you see the site now.

(click to show/hide)

Great, that means at least your Tomcat is running.
But your servler is still not working... else you wouldn't read this. :/
The first step now is to check the logs. The fastest way to do so is just reading them directly on the Server.
To read the logs, do this:

Code: [Select]

sudo nano /opt/tomcat/logs/catalina.1984-01-01.log

Please be aware you have to enter the current date in the filename.
The result should look like this: (sorry for the quality)

You can scroll the text up and down with the arrow keys.
If all of the text looks about the same (no strange paragraphs or super short lines) thats a good sign

To exit this, press CTRL + X

(click to show/hide)

In this case we ahould clear your log files and create some new entries.
Lets first delete the old files:

Code: [Select]

sudo rm /opt/tomcat/logs/ -R
sudo mkdir /opt/tomcat/logs
sudo chown tomcat:tomcat /opt/tomcat/logs -R

Then you should try to create some new entries by reloading the site and accessing the servlet again.
Afterwards try to read the logs, again:

Code: [Select]

sudo nano /opt/tomcat/logs/catalina.1984-01-01.log

Again, please be aware you have to enter the current date in the filename.
The result should look like this: (sorry for the quality)

You can scroll the text up and down with the arrow keys.
If all of the text looks about the same (no strange paragraphs or super short lines) thats a good sign

To exit this, press CTRL + X

(click to show/hide)

Okey, then that might mean something with your servlet isn't right. Your tomcat seems not to be the problem.
You should now check if your servlet was automatically unpacked by tomcat. If not, it didnt even load it in the first place.
To do that, enter this:

Code: [Select]

sudo dir /opt/tomcat/webapps/

As a result you get a list of all files/folders in your webapps/ folder.
There should be a directory (folder) names the same as your WAR file:

(click to show/hide)

That mean's your Servlet wasn't accepted by tomcat because you didn't set the group/owner correctly.
To fix that, type this:

Code: [Select]

sudo chown tomcat:tomcat /opt/tomcat/webapps -R
sudo systemctl restart tomcat

After that please retry if it works now.

(click to show/hide)

In this case lets recreate the logs folder and restart tomcat.
Please enter this:

Code: [Select]

sudo rm /opt/tomcat/logs/ -R
sudo mkdir /opt/tomcat/logs
sudo chown tomcat:tomcat /opt/tomcat/logs -R

Then you should try to create some new entries by reloading the site and accessing the servlet again.
Afterwards try to read the logs, again:

Code: [Select]

sudo nano /opt/tomcat/logs/catalina.1984-01-01.log

Again, please be aware you have to enter the current date in the filename.
The result should look like this: (sorry for the quality)

You can scroll the text up and down with the arrow keys.
If all of the text looks about the same (no strange paragraphs or super short lines) thats a good sign

To exit this, press CTRL + X

(click to show/hide)

Okey, then that might mean something with your servlet isn't right. Your tomcat seems not to be the problem.
You should now check if your servlet was automatically unpacked by tomcat. If not, it didnt even load it in the first place.
To do that, enter this:

Code: [Select]

sudo dir /opt/tomcat/webapps/

As a result you get a list of all files/folders in your webapps/ folder.
There should be a directory (folder) names the same as your WAR file:

(click to show/hide)

That mean's your Servlet wasn't accepted by tomcat because you didn't set the group/owner correctly.
To fix that, type this:

Code: [Select]

sudo chown tomcat:tomcat /opt/tomcat/webapps -R
sudo systemctl restart tomcat

After that please retry if it works now.

(click to show/hide)

Okey, then that might mean something with your servlet isn't right. Your tomcat seems not to be the problem.
You should now check if your servlet was automatically unpacked by tomcat. If not, it didnt even load it in the first place.
To do that, enter this:

Code: [Select]

sudo dir /opt/tomcat/webapps/

As a result you get a list of all files/folders in your webapps/ folder.
There should be a directory (folder) names the same as your WAR file:

(click to show/hide)

That mean's your Servlet wasn't accepted by tomcat because you didn't set the group/owner correctly.
To fix that, type this:

Code: [Select]

sudo chown tomcat:tomcat /opt/tomcat/webapps -R
sudo systemctl restart tomcat

After that please retry if it works now.

(click to show/hide)

If you see any mistakes, pls tell me
*10000 letters ^.^

global2016 · « **Reply #1 on:** December 14, 2016, 02:38:57 am »

xlibman · « **Reply #2 on:** December 14, 2016, 05:25:45 am »

Quote from: global2016 on December 14, 2016, 02:38:57 am

up

Hi, do you need any help?

WalrusIRC

Author Topic: tomcat and ubuntu (Read 578 times)

p2

tomcat and ubuntu

global2016

Re: tomcat and ubuntu

xlibman

Re: tomcat and ubuntu