ConditionalOnProperty

配置Spring Boot通過@ConditionalOnProperty來控制Configuration是否生效

1、matchIfMissing屬性：從application.properties中讀取某個屬性值，如果該值為空，默認值為true

@Configuration
@ConditionalOnClass({ Feign.class }) @ConditionalOnProperty(value = "feign.oauth2.enabled", matchIfMissing = true) public class OAuth2FeignAutoConfiguration { @Bean @ConditionalOnBean(OAuth2ClientContext.class) public RequestInterceptor oauth2FeignRequestInterceptor(OAuth2ClientContext oauth2ClientContext) { return new OAuth2FeignRequestInterceptor(oauth2ClientContext); } }

 

2、havingValue屬性：通過其兩個屬性name以及havingValue來實現的，其中name用來從application.properties中讀取某個屬性值，如果該值為空，則返回false;如果值不為空，則將該值與havingValue指定的值進行比較，如果一樣則返回true;否則返回false。如果返回值為false，則該configuration不生效；為true則生效。

@Configuration
//如果synchronize在配置文件中並且值為true
@ConditionalOnProperty(name = "synchronize", havingValue = "true")
public class SecondDatasourceConfig {

    @Bean(name = "SecondDataSource")
    @Qualifier("SecondDataSource")
    @ConfigurationProperties(prefix = "spring.second.datasource")
    public DataSource jwcDataSource() {
        return DataSourceBuilder.create().build();
    }
}