IotDb在springboot中的应用

---

说明

使用IotDb推荐的原生方法，版本0.12.2
IotDb 官网
github
参考文章

依赖

        <dependency>
            <groupId>org.apache.iotdb</groupId>
            <artifactId>iotdb-session</artifactId>
            <version>0.12.2</version>
        </dependency>

Property&Bean

@ConfigurationProperties(prefix = "iotdb")
public class IotDbProperties {

    @ApiModelProperty("IP")
    private String host;

    @ApiModelProperty("端口号，默认6667")
    private Integer port;

    @ApiModelProperty("用户名")
    private String username;

    @ApiModelProperty("密码")
    private String password;

    @ApiModelProperty("缓冲区大小")
    private Integer fetchSize;

    @Bean
    public Session iotSession(){
        return new Session(host,port,username,password,fetchSize);
    }

}

应用

@Service(value = "IotDb")
public class IotDbConnectServiceImpl {
    @Resource
    private Session iotDbSession;
    //IotDb 的path
    private final String path = "root.xx.xx.xx"

    private Object parseCellInfo() {
        try {
            iotDbSession.open(false);
            String sql = "select * from " + cellPath + " order by time desc limit 1";
            SessionDataSet ret = iotDbSession.executeQueryStatement(sql);
            //列头
            dataSet.getColumnNames();
            //每列的类型
            dataSet.getColumnTypes();
            
            while (dataSet.hasNext()) {
            	//返回一行记录
            	List<Field> fields = ret.next().getFields();
            	if (CollectionUtils.isEmpty(fields)){
                	return null;
            	}
            	//你的处理
            }
        } catch (StatementExecutionException | IoTDBConnectionException e) {
            throw new BusinessException(I18nMsgSystem.DATA_MISS.getMessage());
        }
    }
}

TIPS

返回的field内容如下：

每个field都包含一个dataType字段，要根据这个字段取对应类型的value。

private Object parseField(Field field) {
        switch (field.getDataType()){
            case FLOAT:
                return field.getFloatV();
            case INT32:
                return field.getIntV();
            case INT64:
                return field.getLongV();
            case DOUBLE:
                return field.getDoubleV();
            case BOOLEAN:
                return field.getBoolV();
            case TEXT:
                return field.getStringValue();
            default:
                break;
        }
        return null;
    }