| 类 | 作用 |
|---|---|
| ConditionalOnClass | classpath下有特定类 |
| ConditionalOnBean | 容器中有特定bean |
| ConditionalOnProperty | application.yaml中有特定的key |
| ConditionalOnWebApplication | 容器是一个web容器 |
当前运行的环境为linux才会注入特定的Bean
public class OnLinuxCondition implements Condition {
@Override
public boolean matches(ConditionContext context, AnnotatedTypemetadata metadata) {
Environment environment = context.getEnvironment();
String osName = environment.getProperty("os.name");
if (osName.contains("linux")) {
return true;
}
return false;
}
}
@Configuration
@ComponentScan("com.javashitang.condition")
public class AppConfig {
@Bean
@Conditional(OnLinuxCondition.class)
public User user() {
return new User();
}
}
@Target({ ElementType.TYPE, ElementType.METHOD })
@Retention(RetentionPolicy.RUNTIME)
@Conditional(OnLinuxCondition.class)
public @interface ConditionalOnLinux {
}
@Configuration
@ComponentScan("com.javashitang.condition")
public class AppConfig {
@Bean
@ConditionalOnLinux
public User user() {
return new User();
}
}
参考博客
