如何使用 Spring 引导初始化 Cassandra 键空间和表

Question

我在 Spring 启动应用程序中使用 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，我所做的是，我已经定义了一个类"CassandraConfiguration"扩展了"AbstractCassandraConfiguration"类，如下面的示例所示，我有一个扩展"CassandraRepository"的存储库。当我自己创建密钥空间和表时，应用程序工作正常。

但是，我想在应用程序启动时自动创建密钥空间和表。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。

有没有人知道我可以做些什么来自动创建密钥空间和表？

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。

卡桑德拉配置.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

如果您仍然遇到问题，在 Spring Boot 2 和 SD Cassandra 2.0.3 中，您可以执行这种简单的 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" };
    }

你很好去

Answer 2

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

并排除：

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

在此处获取参考。

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 批注，如果已设置实体基础包，则应自动生成表。

@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 Overpreing中来使其工作，并确保启用@ComponentScan。

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

之前的答案是基于spring-data-cassandra 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。我已经确定了添加到我们公司的 spring-boot 启动器中的自动配置，但您也可以在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()));
        }
    }
}

就我而言，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，则可以将其省略。

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

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

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