Module jdk.jfr
Package jdk.jfr

# Annotation Interface DataAmount

@Retention(RUNTIME) @Target({FIELD,TYPE,METHOD}) public @interface DataAmount
Event field annotation, specifies that a value represents an amount of data (for example, bytes).

The following example shows how the `DataAmount` annotation can be used to set the units `BITS` and `BYTES` to event fields.

    @Name("com.example.ImageRender")
    @Label("Image Render")
    public class ImageRender extends Event {
        @Label("Height")
        long height;

        @Label("Width")
        long width;

        @Label("Color Depth")
        @DataAmount(DataAmount.BITS)
        int colorDepth;

        @Label("Memory Size")
        @DataAmount // bytes by default
        long memorySize;
    }

Since:
  9

## Optional Element Summary

Optional Elements
Modifier and Type
Optional Element
Description
`String`
`value`
Returns the unit for the data amount, by default bytes.

## Field Summary

Fields
Modifier and Type
Field
Description
`static final String`
`BITS`
Unit for bits
`static final String`
`BYTES`
Unit for bytes

## Field Details

### BITS

static final String BITS
Unit for bits

See Also:
  - Constant Field Values

### BYTES

static final String BYTES
Unit for bytes

See Also:
  - Constant Field Values

## Element Details

### value

String value
Returns the unit for the data amount, by default bytes.

Returns:
  the data amount unit, default `BYTES`, not `null`

Default:
  `"BYTES"`