I currently working on an Spring Boot application written in Java 8 using Gradle. What I am looking for is to pass as an argument the server port when running the Jar from the command line.
For example:
java -jar myApplication.jar --port=8888: This runs my Spring boot application using port 8888java -jar myApplication.jar: Since no port number is passed as argument, the spring boot application should run on a default port number (let's say 8080) Can anyone help me with this ?
From Spring boot documentation, the command line is :
java -Dserver.port=8888 -jar myApplication.jar
You can also use Spring boot configuration file as described in the documentation.
Caution Always pass the -D<key>=<value> JVM parameters before the -jar arguments otherwise it wouldn't accept your parameters and then it will run with default values. e.g:
Correct java command to execute the jar on a particular port is:
java -Dserver.port=8888 -jar target/my-application-jar-path.jar
The above command will run the JVM on the port 8888 but the below command
java -jar target/my-application-jar-path.jar -Dserver.port=8888
Will run on the port 8080, it will ignore the JVM parameters after -jar
Best practice in spring-boot application is to set the server.port into the application.properties file as:
server.port=9090
Or on the particular application-<ENV>.properties file with specific ENVIROMENT.
java -jar app.jar --server.port=9000
(taken from 2.1. Accessing Command Line Properties in the Spring documents)
