通过@Profile条件装配

@Profile注解可以在激活不同的配置文件时，实现装配不同的类。

  1. 定义一个Calculate接口，提供sum方法；

    1. public interface Calculate {
    2.  Integer sum(Integer ...numbers);
    3. }

  2. 创建两个实现类Java7Calculate、Java8Calculate，分别通过Java7的for循环和Java8的lambda方式实现sum方法；

  3. 在Java7Calculate上添加注解@Profile(“Java7”)；

    1. @Profile("Java7")
    2. @Service
    3. public class Java7Calculate implements Calculate {
    4.  @Override
    5.  public Integer sum(Integer... numbers) {
    6.      System.out.println("Java7 sum");
    7.      int sum = 0;
    8.      for (int i = 0; i < numbers.length; i++) {
    9.          sum += numbers[i];
    10.      }
    11.      return sum;
    12.  }
    13. }

  4. 在Java8Calculate上添加注解@Profile(“Java8”)；

    1. @Profile("Java8")
    2. @Service
    3. public class Java8Calculate implements Calculate{
    4.  @Override
    5.  public Integer sum(Integer... numbers) {
    6.      System.out.println("Java8 sum");
    7.      return Stream.of(numbers).reduce(0, Integer::sum);
    8.  }
    9. }

  5. 创建启动类ProfileBootstrap，配置profiles为“Java7”；

    @ComponentScan(basePackages = "com.xxx")
public class ProfileBootstrap {
 public static void main(String[] args) {
     ConfigurableApplicationContext context = new SpringApplicationBuilder(ProfileBootstrap.class)
             .web(WebApplicationType.NONE)
             .profiles("Java7")
             .run(args);
     Calculate calculate = context.getBean(Calculate.class);
     Integer sum = calculate.sum(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
     System.out.println("calculate.sum(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)=" + sum);
     context.close();
 }
}

  6. 运行结果如下图： image.png

  7. 配置启动类ProfileBootstrap的profiles为“Java8”；

    @ComponentScan(basePackages = "com.xxx")
public class ProfileBootstrap {
 public static void main(String[] args) {
     ConfigurableApplicationContext context = new SpringApplicationBuilder(ProfileBootstrap.class)
             .web(WebApplicationType.NONE)
             .profiles("Java8")
             .run(args);
     Calculate calculate = context.getBean(Calculate.class);
     Integer sum = calculate.sum(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
     System.out.println("calculate.sum(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)=" + sum);
     context.close();
 }
}

  8. 运行结果如下图： image.png