cassandra + spring-boot使用简记，亲测可用

一. spring-boot 融合cassandra

1. maven 依赖

         
            //不要引入了，避免启动时，必须保证cassandra可用
           
               com.datastax.cassandra
               cassandra-driver-core
               3.4.0
           
   
           
               com.datastax.cassandra
               cassandra-driver-mapping
               3.4.0
           

    

2. 属性文件配置

   cassandra.cluster-name=test-cluster
   cassandra.keyspace-name=test
   cassandra.contact-points=ip1,ip2,ip3
   cassandra.port=9042
   cassandra.username=xiaoming
   cassandra.password=password

    

3. config创建

   @Configuration
   @ConditionalOnProperty(name = "use.db", havingValue = "cassandra")
   public class CassandraConfig {
       @Value("${cassandra.keyspace-name}")
       private String keyspaceName;
       @Value("${cassandra.contact-points}")
       private String host;
       /**
        * 端口
        */
       @Value("${cassandra.port}")
       private int port;
       /**
        * 集群名称
        */
       @Value("${cassandra.cluster-name}")
       private String clusterName;
       /**
        * 用户名
        */
       @Value("${cassandra.username}")
       private String userName;
   
       /**
        * 密码
        */
       @Value("${cassandra.password}")
       private String password;
   
   
       @Bean
       public Cluster cluster() {
           return Cluster.builder()
                   .addContactPoints(host.split(","))
                   .withPort(port)
                   .withClusterName(clusterName)
                   .withCredentials(userName, password)
                   .build();
       }
   
       @Bean
       public NamingStrategy namingStrategy() {
   //java 驼峰命令， 对应cassandra我也选择驼峰命名， 个人喜好^-^
           return new DefaultNamingStrategy(LOWER_CAMEL_CASE, LOWER_CAMEL_CASE);
       }
   
       @Bean
       public Session session(Cluster cluster) {
           Session session = cluster.connect();
           setupKeyspace(session, keyspaceName);
           CassandraHolder.CASS_SESSION = session;
           return session;
       }
   
       private void setupKeyspace(Session session, String keyspace) {
           Map replication = new HashMap<>();
           session.execute(createKeyspace(keyspace).ifNotExists().with().replication(replication));
           session.execute("USE " + keyspace);
       }
   
       @Bean
       public MappingManager mappingManager(Session session, NamingStrategy namingStrategy) {
           PropertyMapper propertyMapper = new DefaultPropertyMapper().setNamingStrategy(namingStrategy);
           MappingConfiguration configuration = MappingConfiguration.builder().withPropertyMapper(propertyMapper).build();
           MappingManager result = new MappingManager(session, configuration);
           CassandraHolder.MANAGER = result;
           return result;
       }
   }

    

4. 改，查，删，批量保存

   /**
   * 留给子类实现
   */
    protected Mapper getMapper(Class clazz) {
           return MANAGER != null ? MANAGER.mapper(clazz) : null;
       }
    public void save(T entity) {
           mapper().save(entity);
       }
   
   
       public int batchSave(List list) {
           if (ArrayUtils.isEmpty(list)) {
               return 0;
           }
           BatchStatement batch = new BatchStatement(BatchStatement.Type.UNLOGGED);
           //任意一个节点写入成功
           batch.setConsistencyLevel(ConsistencyLevel.ANY);
           try {
               for (T data : list) {
                   Statement insert = insertInto(table()).values(column(), bindData(data));
                   batch.add(insert);
                   if (batch.size() == 200) {
                       CASS_SESSION.execute(batch);
                       batch.clear();
                   }
               }
               CASS_SESSION.execute(batch);
               batch.clear();
           } catch (Exception e) {
               log.error("批量存储失败:", e);
           }
   
           return list.size();
       }
   
       public abstract T findOne(String id, String key);
   
       public void delete(T entity) {
           mapper().delete(entity);
       }
   /**
   * 一个典型的entity
   */
   @Data
   @Table(name = "table")
   public class Test{
       @PartitionKey
       private String pk;
       @ClusteringColumn
       private String ck;
       private String ip;
       private Date createTime;
   }
   /*-------------------------批操作实现子类部分代码 开始-----------------------*/
       private String TABLE = "mobileIndex";
       private String[] COLUMN = {"pk", "ck", "ip", "\"createTime\""};
       private Mapper mapper;
   
       @Override
       protected String table() {
           return TABLE;
       }
   
       @Override
       protected String[] column() {
           return COLUMN;
       }
   
       @Override
       protected Object[] bindData(Test entity) {
           return new Object[]{entity.getPk(), entity.getCk(), entity.getIp(), entity.getCreateTime()};
       }
   /*-------------------------批操作实现子类部分代码 结束-----------------------*/

    

二. cassandra 使用特殊点

使用cql建表时，如果表名或属性名想保持驼峰命名法，记得带上双引号，否则均会被定义成纯小写；