如何基于配置属性条件化创建Spring Boot中的Bean

你可以直接使用Spring Boot提供的@ConditionalOnProperty注解实现需求，这个注解专门用于基于配置属性的条件化Bean创建，比@ConditionalOnExpression更直观简洁。

修改后的Bean代码 #

@Bean
@ConditionalOnProperty(name = "enable.userconnection", havingValue = "false", matchIfMissing = false)
public CachingConnectionFactory connectionFactory(AxonConnectionFactory axonConnectionFactory, Integer jmsSessionCacheSize) {
    CachingConnectionFactory connectionFactory = new CachingConnectionFactory();
    connectionFactory.setTargetConnectionFactory(axonConnectionFactory);
    connectionFactory.setReconnectOnException(true);
    connectionFactory.setSessionCacheSize(jmsSessionCacheSize);
    return connectionFactory;
}

@Bean
@ConditionalOnProperty(name = "enable.userconnection", havingValue = "true")
public UserCredentialsConnectionFactoryAdapter userCredentialsConnectionFactoryAdapter() throws Exception {
    UserCredentialsConnectionFactoryAdapter connectionFactoryAdapter = new UserCredentialsConnectionFactoryAdapter();
    connectionFactoryAdapter.setUsername(getUsername());
    connectionFactoryAdapter.setPassword(getPassword());
    connectionFactoryAdapter.setTargetConnectionFactory(
        messagingJMSService().getConnectionFactory(getName()));
    return connectionFactoryAdapter;
}

注解说明 #

• @ConditionalOnProperty(name = "enable.userconnection", havingValue = "false")：仅当配置enable.userconnection=false时，才会创建CachingConnectionFactory Bean
• @ConditionalOnProperty(name = "enable.userconnection", havingValue = "true")：仅当配置enable.userconnection=true时，才会创建UserCredentialsConnectionFactoryAdapter Bean
• matchIfMissing = false（可选）：确保当该配置属性未定义时，不会创建对应的Bean；若希望属性未配置时默认启用CachingConnectionFactory，可将该值改为true

内容的提问来源于stack exchange，提问作者TechGeek