具体做法：

1、首先在pom中添加profiles:

  
   dev
   
     true
   
   
     dev
   
   
     
      org.springframework.boot
      spring-boot-devtools
      true
     
     
      org.springframework.boot
      spring-boot-starter-undertow
     
   
  
 
  
   prod
   
     
      org.springframework.boot
      spring-boot-starter-undertow
     
   
   
     prod
   
  

dev指开发模式，prod指生产模式，如需其他模式，只需要添加profile即可.

2、在pom.xml的build中添加plugin:

  org.apache.maven.plugins
  maven-resources-plugin
  ${maven-resources-plugin.version}
  
   
     default-resources
     validate
     
      copy-resources
     
     
      target/classes
      false
      
        #
      
      
        
         src/main/resources/
         true
         
           **/*.xml
           **/*.yml
         
        
        
         src/main/resources/
         false
         
           **/*.xml
           **/*.yml
         
        
      
     
   
  

该配置用来在打包的时候修改配置文件。

3、编写DefaultProfileUtil工具类来添加默认启动配置文件:

import org.springframework.boot.SpringApplication;
import org.springframework.core.env.Environment;
 
import java.util.HashMap;
import java.util.Map;
 
/**
 * Utility class to load a Spring profile to be used as default
 * when there is no spring.profiles.active set in the environment or as command line argument.
 * If the value is not available in application.yml then dev profile will be used as default.
 */
public final class DefaultProfileUtil {
 
  private static final String SPRING_PROFILE_DEFAULT = "spring.profiles.default";
 
  private DefaultProfileUtil(){
  }
 
  /**
   * Set a default to use when no profile is configured.
   *
   * @param app the spring application
   */
  public static void addDefaultProfile(SpringApplication app) {
    Map defProperties = new HashMap<>();
    /*
    * The default profile to use when no other profiles are defined
    * This cannot be set in the application.yml file.
    * See https://github.com/spring-projects/spring-boot/issues/1219
    */
    defProperties.put(SPRING_PROFILE_DEFAULT, Constants.SPRING_PROFILE_DEVELOPMENT);
    app.setDefaultProperties(defProperties);
    System.out.println(app);
  }
 
  /**
   * Get the profiles that are applied else get default profiles.
   */
  public static String[] getActiveProfiles(Environment env) {
    String[] profiles = env.getActiveProfiles();
    if (profiles.length == 0) {
      return env.getDefaultProfiles();
    }
    return profiles;
  }
}

public class Constants {
 
  public static final String SPRING_PROFILE_DEVELOPMENT = "dev";
  public static final String SPRING_PROFILE_PRODUCTION = "prod";
  private Constants() {
  }
}

4、修改application.yml配置文件，添加(采用application.properties文件)：

spring:
  profiles:
   active: #spring.profiles.active#

maven的构建的时候会替换#spring.profiles.active#

5、修改项目的启动类：

@SpringBootApplication
public class Demo1Application {
 
  private static final Logger log = LoggerFactory.getLogger(Demo1Application.class);
 
  public static void main(String[] args) {
   SpringApplication app = new SpringApplication(Demo1Application.class);
   DefaultProfileUtil.addDefaultProfile(app);
   Environment env = app.run(args).getEnvironment();
   log.info("\n----------------------------------------------------------\n\t" +
         "Application '{}' is running! Access URLs:\n\t" +
         "Local: \t\thttp://localhost:{}\n\t" +
         "----------------------------------------------------------",
      env.getProperty("spring.application.name"),
      env.getProperty("server.port"));
  }
}

以上修改完成之后，在启动的时候会显示：The following profiles are active: dev 默认dev模式切换成功。

6、构建项目：

采用mvn clean package -Pprod命令构建，最后的配置文件会被改成：