How to set Spring profile from system variable?

问题

I have a Spring project which uses another project. Each project has its own spring profile initialize from java code using applicationContext.xml and *.properties for each profile. I inject the profile from args[]. The problem is that second project uses the default configuration for the env from the applicationContext.xml I can not inject the env from args[] to the second project and I tried looking for an article which will explain how Spring profile works.

1. Is there a hierarchy on which it will look the profile when default is not configured at applicationContext.xml ?
2. Is System var stronger than applicationContext.xml configuration?
3. What you think is the best solution to my challenge?

Articles on that subject or even examples would be most appreciated!! Thanks in advance.

回答1:

SPRING_PROFILES_ACTIVE is the environment variable to override/pick Spring profile

回答2:

If you provide your JVM the Spring profile there should be no problems:

java -Dspring.profiles.active=development -jar yourApplication.jar 

Also see Spring-Documentation:

http://docs.spring.io/spring-boot/docs/current/reference/html/howto-properties-and-configuration.html

69.5 Set the active Spring profiles

The Spring Environment has an API for this, but normally you would set a System property (spring.profiles.active) or an OS environment variable (SPRING_PROFILES_ACTIVE). E.g. launch your application with a -D argument (remember to put it before the main class or jar archive):

$ java -jar -Dspring.profiles.active=production demo-0.0.1-SNAPSHOT.jar

In Spring Boot you can also set the active profile in application.properties, e.g.

spring.profiles.active=production

A value set this way is replaced by the System property or environment variable setting, but not by the SpringApplicationBuilder.profiles() method. Thus the latter Java API can be used to augment the profiles without changing the defaults.

See Chapter 25, Profiles in the ‘Spring Boot features’ section for more information.

回答3:

I normally configure the applicationContext using Annotation based configuration rather than XML based configuration. Anyway, I believe both of them have the same priority.

*Answering your question, system variable has higher priority *

---

Getting profile based beans from applicationContext

• Use @Profile on a Bean

  @Component
  @Profile("dev")
  public class DatasourceConfigForDev
  

  Now, the profile is dev

  Note : if the Profile is given as @Profile("!dev") then the profile will exclude dev and be for all others.

• Use profiles attribute in XML

  <beans profile="dev">
    <bean id="DatasourceConfigForDev" class="org.skoolguy.profiles.DatasourceConfigForDev"/>
  </beans>
  

---

Set the value for profile:

• Programmatically via WebApplicationInitializer interface

  In web applications, WebApplicationInitializer can be used to configure the ServletContext programmatically

  @Configuration
  public class MyWebApplicationInitializer implements WebApplicationInitializer {
  
    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {
      servletContext.setInitParameter("spring.profiles.active", "dev");
    }
  }
  

• Programmatically via ConfigurableEnvironment

  You can also set profiles directly on the environment:

  @Autowired
  private ConfigurableEnvironment env;
  
  ...
  
  env.setActiveProfiles("dev");
  

• Context Parameter in web.xml

  profiles can be activated in the web.xml of the web application as well, using a context parameter:

  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/app-config.xml</param-value>
  </context-param>
  <context-param>
    <param-name>spring.profiles.active</param-name>
    <param-value>dev</param-value>
  </context-param>
  

• JVM System Parameter

  The profile names passed as the parameter will be activated during application start-up:

  -Dspring.profiles.active=dev
  

  In IDEs, you can set the environment variables and values to use when an application runs. The following is the Run Configuration in Eclipse:

• Environment Variable

  to set via command line : export spring_profiles_active=dev

Any bean that does not specify a profile belongs to “default” profile.

---

The priority order is :

1. Context parameter in web.xml
2. WebApplicationInitializer
3. JVM System parameter
4. Environment variable

回答4:

If i run the command line : java -Dspring.profiles.active=development -jar yourApplication.jar from my webapplication directory it states that the path is incorrect. So i just defined the profile in manualy in the application.properties file like this :

spring.profiles.active=mysql 

or

spring.profiles.active=postgres

or

spring.profiles.active=mongodb

回答5:

If you are using docker to deploy the spring boot app, you can set the profile using the flag e:

docker run -e "SPRING_PROFILES_ACTIVE=prod" -p 8080:8080 -t r.test.co/myapp:latest

回答6:

My solution is to set the environment variable as spring.profiles.active=development. So that all applications running in that machine will refer the variable and start the application. The order in which spring loads a properties as follows

application.properties
system properties
environment variable

来源：https://stackoverflow.com/questions/38520638/how-to-set-spring-profile-from-system-variable