BigDecimal Support

[pavlo-pastushok]

Can you please, add BigDecimal support into InfluxDBResultMapper. Thanks

[shimonm]

I am also in need of this change, currently using Double, but I am afraid that this won't do in the long run, when it comes to really big decimal precision numbers. Thanks.

[asashour]

I quickly checked, but I see that both InfluxDB and Java use IEEE 754 64-bit floating point numbers.

Below is a sample case, in which both systems return the same values. Can you provider a case in which there are different ones?

> insert hello value=12345678901234567890.12345678901234567890
> insert hello value=1234567890.12345678901234567890
> select * from hello
name: hello
time                value
----                -----
1548082690161733800 12345678901234567000
1548082802711734800 1234567890.1234567

public class InfluxTest {

    private InfluxDB influxDB;
    private String database;
    private InfluxDBResultMapper mapper = new InfluxDBResultMapper();
    String measurement = "hello";

    @Before
    public void setup() {
        influxDB = InfluxDBFactory.connect("http://localhost:8086", "root", "root");
        database = "mydb";
        influxDB.createDatabase(database);
        influxDB.setDatabase(database);
    }

    @After
    public void cleanup() {
        influxDB.close();
    }

    @Test
    public void test() {
        QueryResult queryResult = influxDB.query(new Query("SELECT * FROM " + measurement, database));

        List<Abc> list = mapper.toPOJO(queryResult, Abc.class);
        for (Abc a : list) {
            System.out.println(String.format("%f", a.value));
            System.out.println(a.value);
        }
    }
    
    @Measurement(name="hello")
    public static class Abc {
        
        @Column(name = "value")
        private double value;

    }
}

With output:

12345678901234567000.000000
1.2345678901234567E19
1234567890.123457
1.2345678901234567E9