Introduction to Tomcat Environment Variables
There are various environment variables related to tomcat that can help us specify the behavior and the information about various parameters that describe how the tomcat will function once it’s started. In this article, we will have a look at the overview of these tomcat environment variables, how we can set the values of the same inside the tomcat home directory also known as Catalina folder, and an example demonstrating the implementation of setting the value of environment variable for tomcat and finally, we will conclude our statement.
Overview of Tomcat Environment Variables
There are various environment variable names that can be set inside the setenv.bat and setenv.sh files. The list of a few important environment variables is as described in the below table –
| Name of the environment variable | Details |
| CATALINA_BASE | This helps in pointing out the folder of the build directory. |
| CATALINA_HOME | This variable helps in specifying the root directory if the installation of tomcat. |
| CATALINA_OPTS | When we execute the run or start command, at that time the runtime java options are used. |
| CATALINA_OUT | The stderr and stdout commands will be redirected on the full path specified here. |
| CATALINA_TMPDIR | The JVM i.e java.io.tmpdir package of it will make use of this directory that is the location of the temporary folder. |
| CATALINA_PID | This is the name of the file where the pid that is process id for Catalina startup process for java exists when we make the use of start or fork command. |
| JRE_HOME | The java runtime installation is pointed out by this path and the default value of this variable is empty. |
| JAVA_HOME | The JDK or java development kit is pointed out by this path. |
| JAVA_ENDORSED | This variable contains the comma-separated list of all the paths of the directories where the jar files are present helping to create a replacement to the APIs that are used out of the JCP that stands for SAX and DOM APIs for W3C. We can even use this for updating the code implementation. The default value of this environment variable is the folder where we have installed the Tomcat web server and inside that endorsed folder. |
| JAVA_OPTS | Whenever we perform the operation of stop, start or run then this command is executed that includes the java runtime options. |
| JPDA_ADDRESS | Whenever we start the jpda start command then this runtime option of java gets called. The default value of this env variable is 8000. |
| JPDA_TRANSPORT | When we execute the command jpda start this environment variable is used that has the default value set to dt_socket. |
| JPDA_OPTS | This is also one of the runtime options of java that is used when we execute the jpda start command. If we make use of the environment variables JPDA_TRANSPORT, JPDA_SUSPEND or JPDA_ADDRESS then this is completely ignored. Therefore, it is required that we should mention al of the variable values. |
| JPDA_SUSPEND | This is also a runtime option of java that is used when we make the use of jpda start command and helps us specify when the JVM should suspend the execution. |
| LOGGING_MANAGER | This helps us to override the existing manager of logging by simply specifying in one line. |
| LOGGING_CONFIG | This variable helps in overriding the config file of the tomcat logging system in just one line. |
How to set up tomcat environment variables?
Let us firstly have a look at how we can set the values of the environment variables of tomcat in the windows platform. The most popular way of doing so is using the file called setenv.bat which is an additional file in which all the entries of the variables along with the key and value pairs are mentioned inside this file. Let’s say that the two environment variables namely JAVA_OPTS and JAVA_HOME that are required for tomcat can be set by following the below steps –
- Navigate to the folder CATALINA_HOME/bin and create a new file with the name setenv.bat
- You can open this file in any of your favorite editors and add the below commands or lines to it –
Set JAVA_OPTS = -Xms1G -Xmx1G
Set JAVA_HOME = The route or location of your installed Java development kit that is JDK
There is no need for mentioning the quotation marks in this file as the statements written here will get called automatically when we will start the tomcat web server.
We can set the values of the environment variables related to tomcat inside the setenv.sh file that is present inside the directory where you have installed tomcat server and inside that the bin folder where the files namely Catalina. sh, setenv. sh, and setenv.bat will be present. The setenv. sh, and the file setenv.bat files are the script files that get called and executed automatically when we start the tomcat web server. As they are not created when you install tomcat, you will need to create them later.
Tomcat Environment Variables Examples
Let us consider one example where we need to modify the path of JDK specified in the environment variable JAVA_HOME located in the setenv.sh file of tomcat directory in Linux platform. For this, you can execute the following commands –
Search for the file setenv. sh and then open it in the editor.
Search for the word JAVA_HOME in the file.
Edit its value to the new value that you want to set and save the file.
Restart the tomcat server to reflect the changes.
The format of specifying this environment variable is as shown below –
Export JAVA_HOME = “The location of the java development kit that is its absolute path”
Setting User tomcat environment variables –
We have already seen how we can set the environment variables of tomcat in windows. Now, let us understand the process that we need to follow when setting up the user tomcat environment variable. The same process as that of windows is followed. But here, we will need to create a file named setenv. sh. Let us try to set the values of JAVA_OPTS and JAVA_HOME environment variables in Linux.
We will start by navigating to the folder CATALIN_HOME/bin and create a new file named setenv. sh over there. This file will get called automatically once we start the tomcat web server.
Then you can open this file in any of the editors and write the following lines in it –
Export JAVA_OPTS = “-Xmx1G Xms1G”
Export JAVA_HOME = “The location of the java development kit that is its absolute path”
Here, you need to keep one thing in mind that quotation marks are required in the Linux platform.
Conclusion
The Tomcat web server has some environment variables present for describing its behavior. This can be specified in the files named setenv. sh and setenv.bat files that should be created by us. These files automatically get called when the tomcat is started.
Recommended Articles
This is a guide to Tomcat Environment Variables. Here we discuss the Introduction, overviews, How to set up tomcat environment variables, examples with code implementation. You may also have a look at the following articles to learn more –
