Spring数据Cassandra配置动态更改

Question

我正在尝试对我的应用程序做类似的事情。我正在使用以下版本的Spring boot和Cassandra：

Spring数据卡桑德拉-2.0。8.释放Spring护套启动器父级-2.0。4.RELEASE我需要动态更改Cassandra的一些属性（主要是主机名），并希望它与应用程序建立新的连接。对于配置更改，我们有内部云配置更改管理，它在更改时运行良好，并侦听更改。这是我的班级：

@Configuration
@Order(Ordered.HIGHEST_PRECEDENCE)
@RefreshScope
@EnableCassandraRepositories(basePackages = {"com.*.*.*.dao.repo"})
public class AppConfig {

    private static final Logger LOGGER = LoggerFactory.getLogger(AppConfig.class);

    @Value("${application['cassandraPort']}")
    private String cassandraPort;

    @Value("${application['cassandraEndpoint']}")
    private String cassandraEndpoint;

    @Value("${application['keyspaceName']}")
    private String keyspaceName;

    @Value("${application['cassandraConsistency']}")
    private String cassandraConsistency;

    @Value("${application['cassandraUserName']}")
    private String cassandraUserName;




    @Autowired
    private AppConfig appConfig;


    public AppConfig() {

        System.out.println("AppConfig Constructor");

    }




    public String getCassandraPort() {
        return cassandraPort;
    }

    public void setCassandraPort(String cassandraPort) {
        this.cassandraPort = cassandraPort;
    }

    public String getCassandraEndpoint() {
        return cassandraEndpoint;
    }

    public void setCassandraEndpoint(String cassandraEndpoint) {
        this.cassandraEndpoint = cassandraEndpoint;
    }

    public String getKeyspaceName() {
        return keyspaceName;
    }

    public void setKeyspaceName(String keyspaceName) {
        this.keyspaceName = keyspaceName;
    }

    public String getCassandraConsistency() {
        return cassandraConsistency;
    }

    public void setCassandraConsistency(String cassandraConsistency) {
        this.cassandraConsistency = cassandraConsistency;
    }

    public String getCassandraUserName() {
        return cassandraUserName;
    }

    public void setCassandraUserName(String cassandraUserName) {
        this.cassandraUserName = cassandraUserName;
    }




    @Bean
    // @RefreshScope
    public CassandraConverter converter() {
        return new MappingCassandraConverter(this.mappingContext());
    }


    @Bean
    // @RefreshScope
    public CassandraMappingContext mappingContext() {
        return new CassandraMappingContext();
    }


    @Bean
    //@RefreshScope
    public CassandraSessionFactoryBean session() {


        CassandraSessionFactoryBean session = new CassandraSessionFactoryBean();

        session.setCluster(this.cluster().getObject());
        session.setKeyspaceName(appConfig.getKeyspaceName());
        session.setConverter(this.converter());
        session.setSchemaAction(SchemaAction.NONE);
        return session;
    }

    @Bean
    //@RefreshScope
    public CassandraClusterFactoryBean cluster() {
        CassandraClusterFactoryBean cluster = new CassandraClusterFactoryBean();

        cluster.setContactPoints(appConfig.getCassandraEndpoint());
        cluster.setPort(Integer.valueOf(appConfig.getCassandraPort()));
        cluster.setUsername(appConfig.getCassandraUserName());
        cluster.setPassword("password");
        cluster.setQueryOptions(new QueryOptions().setConsistencyLevel(ConsistencyLevel.LOCAL_QUORUM));

        return cluster;
    }

}

但是，当我尝试将@RefreshScope与该配置类一起使用时，应用程序无法启动。这是它在控制台中显示的内容：

***************************
APPLICATION FAILED TO START
***************************

Description:

Parameter 2 of constructor in org.springframework.boot.autoconfigure.data.cassandra.CassandraDataAutoConfiguration required a bean of type 'com.datastax.driver.core.Cluster' that could not be found.
    - Bean method 'cassandraCluster' not loaded because auto-configuration 'CassandraAutoConfiguration' was excluded


Action:

Consider revisiting the entries above or defining a bean of type 'com.datastax.driver.core.Cluster' in your configuration.

有没有一些关于使用@ReresScope与Cassandra Bean的指南？如果早些时候有人这样做了，你能分享吗？

Answer 1

你在这里混合了一些东西。

1. 配置包含属性和bean定义

为了清理，我们将尽可能多地重用Spring Boot提供的内容，并且只声明真正需要的内容。

按照以下步骤解决问题（基于上述代码）：

1. 创建一个封装属性的@ConfigurationPropertiesbean，或者更好地重用CassandraProperties。
2. 重新启用CassandraAutoConfiguration并删除您自己的MappingContext和CassandraConzerbean，只保留Cluster和会话bean定义
3. 根据需要声明Cluster和会话bean，并使它们使用@ReresScope。你的配置类应该看起来像：

配置示例：

@Configuration
public class MyConfig {

    @Bean(destroyMethod = "close")
    @RefreshScope
    public Cluster cassandraCluster(CassandraProperties properties) {
        Cluster.Builder builder = Cluster.builder().addContactPoints(properties.getContactPoints().toArray(new String[0]))
                .withoutJMXReporting();

        return builder.build();
    }

    @Bean(destroyMethod = "close")
    @RefreshScope
    public Session cassandraSession(CassandraProperties properties, Cluster cluster) {
        return cluster.connect(properties.getKeyspaceName());
    }
}