如何使用 Spring Boot 初始化 Cassandra 键空间和表

Question

我在 Spring Boot 应用程序中使用 Cassandra 作为数据源，并希望在应用程序启动之前初始化数据库。

到目前为止，我已经定义了一个扩展“AbstractCassandraConfiguration”类的“CassandraConfiguration”类，如下面的示例所示，我有一个扩展“CassandraRepository”的存储库。当我自己创建键空间和表时，应用程序运行良好。

但是，我想在应用程序启动时自动创建键空间和表。为此，我在资源文件夹下提供了一个 schema.cql 文件，但我无法使该脚本工作。

有谁知道我可以做些什么来自动创建键空间和表？

谢谢。

编辑：我正在使用 Cassandra 2.0.9、spring-boot 1.3.2.RELEASE 和 datastax cassandra 驱动程序 2.1.6 版本。

CassandraConfiguration.java

@Configuration
@PropertySource(value = { "classpath:cassandra.properties" })
@EnableCassandraRepositories(basePackages = { "bla.bla.bla.repository" })
public class CassandraConfiguration extends AbstractCassandraConfiguration {

    @Autowired
    private Environment environment;


    @Bean
    public CassandraClusterFactoryBean cluster() {
        CassandraClusterFactoryBean cluster = new CassandraClusterFactoryBean();
        cluster.setContactPoints( environment.getProperty( "cassandra.contactpoints" ) );
        cluster.setPort( Integer.parseInt( environment.getProperty( "cassandra.port" ) ) );
        return cluster;
    }


    @Bean
    public CassandraMappingContext cassandraMapping() throws ClassNotFoundException {
        return new BasicCassandraMappingContext();
    }


    @Bean
    public CassandraConverter converter() throws ClassNotFoundException {
        return new MappingCassandraConverter(cassandraMapping());
    }


    @Override
    protected String getKeyspaceName() {
        return environment.getProperty( "cassandra.keyspace" );
    }


    @Bean
    public CassandraSessionFactoryBean session() throws Exception {

        CassandraSessionFactoryBean session = new CassandraSessionFactoryBean();
        session.setCluster(cluster().getObject());
        session.setKeyspaceName(environment.getProperty("cassandra.keyspace"));
        session.setConverter(converter());
        session.setSchemaAction(SchemaAction.NONE);

        return session;
    }


    @Override
    public SchemaAction getSchemaAction() {
        return SchemaAction.RECREATE_DROP_UNUSED;
    }
}

Answer 1

如果您仍然遇到此问题，在 Spring Boot 2 和 SD Cassandra 2.0.3 中，您可以进行这种简单的 Java 配置并开箱即用地设置所有内容。

@Configuration
@EnableCassandraRepositories(basePackages = "com.example.repository")
public class DbConfigAutoStart extends AbstractCassandraConfiguration {

    /*
     * Provide a contact point to the configuration.
     */
    @Override
    public String getContactPoints() {
        return "exampleContactPointsUrl";
    }

    /*
     * Provide a keyspace name to the configuration.
     */
    @Override
    public String getKeyspaceName() {
        return "exampleKeyspace";
    }

    /*
     * Automatically creates a Keyspace if it doesn't exist
     */
    @Override
    protected List<CreateKeyspaceSpecification> getKeyspaceCreations() {
        CreateKeyspaceSpecification specification = CreateKeyspaceSpecification
                .createKeyspace("exampleKeyspace").ifNotExists()
                .with(KeyspaceOption.DURABLE_WRITES, true).withSimpleReplication();
        return Arrays.asList(specification);
    }


    /*
     * Automatically configure a table if doesn't exist
     */
    @Override
    public SchemaAction getSchemaAction() {
        return SchemaAction.CREATE_IF_NOT_EXISTS;
    }


    /*
     * Get the entity package (where the entity class has the @Table annotation)
     */
    @Override
    public String[] getEntityBasePackages() {
        return new String[] { "com.example.entity" };
    }

你很高兴

Answer 2

您的返回类型 BasicCassandraMappingContext() 可能已被弃用。使用

@Bean
public CassandraMappingContext mappingContext() throws ClassNotFoundException {
    CassandraMappingContext mappingContext= new CassandraMappingContext();
    mappingContext.setInitialEntitySet(getInitialEntitySet());
    return mappingContext;
}
@Override
public String[] getEntityBasePackages() {
    return new String[]{"base-package name of all your entity, annotated 
with @Table"};
}

@Override
protected Set<Class<?>> getInitialEntitySet() throws ClassNotFoundException {
    return CassandraEntityClassScanner.scan(getEntityBasePackages());
}

而不是，

@Bean
public CassandraMappingContext cassandraMapping() throws ClassNotFoundException {
    return new BasicCassandraMappingContext();
}

还设置：

session.setSchemaAction(SchemaAction.RECREATE_DROP_UNUSED);

和排除：

@Override
public SchemaAction getSchemaAction() {
    return SchemaAction.RECREATE_DROP_UNUSED;
}

获取参考here。

Answer 3

我正在使用spring-boot 1.5.10.RELEASE 和cassandra 3.0.16，但您可以尝试缩小版本。要创建密钥空间，您可以从 application.yml 或 application.properties 导入密钥空间名称。使用 @Table 注释，如果您设置了实体基础包，您的表应该会自动生成。

@Value("${cassandra.keyspace}")
private String keySpace;

@Override
public String[] getEntityBasePackages() {
    return new String[]{"com.example.your.entities"};
}

@Override
protected List<CreateKeyspaceSpecification> getKeyspaceCreations() {
    return Arrays.asList(
            CreateKeyspaceSpecification.createKeyspace()
                    .name(keySpace)
                    .ifNotExists()
    );
}

Answer 4

最后我通过将 setKeyspaceCreations(getKeyspaceCreations()) 添加到 CassandraClusterFactoryBean 覆盖并确保启用 @ComponentScan 来使其工作。

import com.datastax.driver.core.PlainTextAuthProvider;
import com.datastax.driver.core.policies.ConstantReconnectionPolicy;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.cassandra.config.*;
import org.springframework.data.cassandra.core.cql.keyspace.CreateKeyspaceSpecification;
import org.springframework.data.cassandra.core.cql.keyspace.DropKeyspaceSpecification;
import org.springframework.data.cassandra.core.cql.keyspace.KeyspaceOption;
import org.springframework.data.cassandra.repository.config.EnableReactiveCassandraRepositories;

import java.util.Arrays;
import java.util.List;



@Configuration
@EnableReactiveCassandraRepositories(basePackages = "com.company.domain.data")
public class CassandraConfig extends AbstractReactiveCassandraConfiguration{
@Value("${spring.data.cassandra.contactpoints}") private String contactPoints;
@Value("${spring.data.cassandra.port}") private int port;
@Value("${spring.data.cassandra.keyspace-name}") private String keyspace;

@Value("${spring.data.cassandra.username}") private String userName;
@Value("${spring.data.cassandra.password}") private String password;
@Value("${cassandra.basepackages}") private String basePackages;


@Override protected String getKeyspaceName() {
    return keyspace;
}
@Override protected String getContactPoints() {
    return contactPoints;
}
@Override protected int getPort() {
    return port;
}
@Override public SchemaAction getSchemaAction() {
    return SchemaAction.CREATE_IF_NOT_EXISTS;
}
@Override
public String[] getEntityBasePackages() {
    return new String[]{"com.company.domain.data"};
}

@Override
public CassandraClusterFactoryBean cluster() {
    PlainTextAuthProvider authProvider = new PlainTextAuthProvider(userName, password);

    CassandraClusterFactoryBean cluster=new CassandraClusterFactoryBean();

    cluster.setJmxReportingEnabled(false);
    cluster.setContactPoints(contactPoints);
    cluster.setPort(port);
    cluster.setAuthProvider(authProvider);
    cluster.setKeyspaceCreations(getKeyspaceCreations());
    cluster.setReconnectionPolicy(new ConstantReconnectionPolicy(1000));

    return cluster;
}


@Override
protected List<CreateKeyspaceSpecification> getKeyspaceCreations() {

    CreateKeyspaceSpecification specification = CreateKeyspaceSpecification.createKeyspace(keyspace)
            .ifNotExists()
            .with(KeyspaceOption.DURABLE_WRITES, true);

    return Arrays.asList(specification);
}



@Override
protected List<DropKeyspaceSpecification> getKeyspaceDrops() {
    return Arrays.asList(DropKeyspaceSpecification.dropKeyspace(keyspace));
}



}

Answer 5

之前的答案基于来自spring-data-cassandra 的AbstractCassandraConfiguration。如果您使用spring-boot，那么它可以为您自动配置Cassandra，无需扩展AbstractCassandraConfiguration。但是，即使在这种情况下，您也需要做一些工作来自动创建密钥空间。我已经决定在我们公司的 spring-boot 启动器中添加一个自动配置，但您也可以在您的应用程序中将其定义为常规配置。

/**
 * create the configured keyspace before the first cqlSession is instantiated. This is guaranteed by running this
 * autoconfiguration before the spring-boot one.
 */
@ConditionalOnClass(CqlSession.class)
@ConditionalOnProperty(name = "spring.data.cassandra.create-keyspace", havingValue = "true")
@AutoConfigureBefore(CassandraAutoConfiguration.class)
public class CassandraCreateKeyspaceAutoConfiguration {

    private static final Logger logger = LoggerFactory.getLogger(CassandraCreateKeyspaceAutoConfiguration.class);

    public CassandraCreateKeyspaceAutoConfiguration(CqlSessionBuilder cqlSessionBuilder, CassandraProperties properties) {
        // It's OK to mutate cqlSessionBuilder because it has prototype scope.
        try (CqlSession session = cqlSessionBuilder.withKeyspace((CqlIdentifier) null).build()) {
            logger.info("Creating keyspace {} ...", properties.getKeyspaceName());
            session.execute(CreateKeyspaceCqlGenerator.toCql(
                    CreateKeyspaceSpecification.createKeyspace(properties.getKeyspaceName()).ifNotExists()));
        }
    }
}

在我的例子中，我还添加了一个配置属性来控制创建，spring.data.cassandra.create-keyspace，如果您不需要灵活性，可以省略它。

请注意，spring-boot 自动配置取决于某些配置属性，这是我在开发环境中拥有的：

spring:
  data:
    cassandra:
      keyspace-name: mykeyspace
      contact-points: 127.0.0.1
      port: 9042
      local-datacenter: datacenter1
      schema-action: CREATE_IF_NOT_EXISTS
      create-keyspace: true

更多详情：spring-boot and Cassandra