helper.database.cassandra.CassandraEntity Maven / Gradle / Ivy
package helper.database.cassandra;
import com.datastax.driver.core.DataType;
import com.datastax.driver.core.schemabuilder.Create;
import com.datastax.driver.core.schemabuilder.SchemaBuilder;
import com.datastax.driver.extras.codecs.jdk8.InstantCodec;
import com.datastax.driver.mapping.Mapper;
import com.datastax.driver.mapping.annotations.Column;
import com.google.common.base.MoreObjects;
import java.time.Instant;
import java.util.Objects;
/**
* Cassandra 实体。
*
* CQL 数据库除了主键之外，还有分区键，为了保证 {@link Mapper} 的正常使用，实体将只使用分区键。
*
* @author mrzhqiang
*/
public abstract class CassandraEntity {
protected static final String COL_COMMON_CREATED = "created";
protected static final String COL_COMMON_MODIFIED = "modified";
protected static final String COL_COMMON_DESCRIPTION = "description";
@Column(name = COL_COMMON_CREATED, codec = InstantCodec.class)
public Instant created = Instant.now();
@Column(name = COL_COMMON_MODIFIED, codec = InstantCodec.class)
public Instant modified = Instant.now();
@Column(name = COL_COMMON_DESCRIPTION)
public String description;
/**
* 返回秘钥空间名字。
*
* @return 秘钥空间名字。
*/
abstract public String keyspaceName();
/**
* 返回表名。
*
* @return 表名。
*/
abstract public String tableName();
/**
* 返回创建语句，用来检查表是否已创建。
*
* @return CQL 语句类。
*/
public Create createCQL() {
return SchemaBuilder.createTable(keyspaceName(), tableName())
.ifNotExists()
.addColumn(COL_COMMON_CREATED, DataType.timestamp())
.addColumn(COL_COMMON_MODIFIED, DataType.timestamp())
.addColumn(COL_COMMON_DESCRIPTION, DataType.text());
}
/**
* toString 的辅助方法。
*
* @return Guava 的 toString 辅助类。
*/
protected MoreObjects.ToStringHelper toStringHelper() {
return MoreObjects.toStringHelper(this)
.add("created", created)
.add("modified", modified)
.add("description", description);
}
@Override public int hashCode() {
return Objects.hash(created, modified, description);
}
@Override public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof CassandraEntity)) {
return false;
}
CassandraEntity other = ((CassandraEntity) obj);
return Objects.equals(this.created, other.created)
&& Objects.equals(this.modified, other.modified)
&& Objects.equals(this.description, other.description);
}
}