Spring Boot Multi‑Environment Configuration and JVM Parameter Tuning Guide

Purpose

The goal is to become familiar with Spring Boot multi‑environment configuration and understand the meaning of parameters when launching a Spring Boot JAR.

Configuration Files

# springboot multi‑environment configuration server: port: 8080 servlet: context-path: /springboot-params-demo spring: profiles: active: test logging: level: root: INFO org: springframework: security: WARN web: ERROR file: path: ./logs name: './logs/springboot-params-demo.log' pattern: file: '%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50}:%L - %msg%n' console: '%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50}:%L - %msg%n'

# application-test.yml myParam: 'on'

# application-prod.yml myParam: 'close'

Retrieving Custom Parameters

package com.demo.config; import lombok.extern.slf4j.Slf4j; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Value; import org.springframework.boot.CommandLineRunner; import org.springframework.core.env.Environment; import org.springframework.stereotype.Component; import java.util.Arrays; @Component @Slf4j public class MyParamRunner implements CommandLineRunner { @Value("${myParam}") String myParam; @Autowired Environment environment; @Override public void run(String... args) throws Exception { log.info("本地设置的参数myParam为：{}", myParam); log.info(environment.toString()); log.info(String.valueOf(Arrays.asList(environment.getActiveProfiles()))); } }

Packaging and Running

After building, the JAR springboot-jvm-params-1.0-SNAPSHOT.jar is placed in the target directory. Run it with:

java -jar /usr/local/springboot_demos/springboot-port8001/springboot-jvm-params-1.0-SNAPSHOT.jar

Modifying Startup Configuration

Two ways to set the active profile:

System variable: java -jar -Dspring.profiles.active=prod /usr/local/springboot_demos/springboot-port8001/springboot-jvm-params-1.0-SNAPSHOT.jar

Command‑line argument: java -jar /usr/local/springboot_demos/springboot-port8001/springboot-jvm-params-1.0-SNAPSHOT.jar --spring.profiles.active=prod --myParam='test'

Note that command‑line arguments override JVM system variables, which in turn override values from configuration files (priority: file < < JVM < < command line).

JVM Startup Parameters Explained

The article lists extensive JVM options such as heap settings, GC logging, CMS collector tuning, thread counts, network timeouts, and Spring‑specific properties. Example snippet:

/usr/local/jdk/jdk1.8.0_261/bin/java -jar -server \ -XX:+HeapDumpOnOutOfMemoryError \ -XX:HeapDumpPath=/usr/local/springboot_demos/springboot-port8001/dump/heap/oom.hprof \ -Djava.io.tmpdir=/usr/local/springboot_demos/springboot-port8001/tmp/ \ -Dserver.port=8001 \ -XX:+PrintGCDetails \ -XX:+PrintGCDateStamps \ -Dspring.profiles.active=prod \ /usr/local/springboot_demos/springboot-port8001/springboot-jvm-params-1.0-SNAPSHOT.jar jvmparams

These options control memory allocation, garbage‑collection behavior, logging, and other runtime characteristics, enabling fine‑grained performance tuning for Spring Boot services.