DataScheme (QD Core API 3.342)

All Known Implementing Classes:

DefaultScheme
```
@Service
public interface DataScheme
```
The DataScheme defines overall scheme of data records and fields. It contains an indexed list of data records and provides quick access to them.
For the QD, the data scheme represents description of processed data. It shall be provided by some external entity (the APS), and it shall be constant throughout the lifetime of the QD systems.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods Deprecated Methods
Modifier and Type	Method and Description
`DataIntField`	`findIntFieldByName(String name)` Deprecated. Find record using `findRecordByName(String)` and find its field using `DataRecord.findFieldByName(String)`.
`DataObjField`	`findObjFieldByName(String name)` Deprecated. Find record using `findRecordByName(String)` and find its field using `DataRecord.findFieldByName(String)`.
`DataRecord`	`findRecordByName(String name)` Returns data record by its name.
`SymbolCodec`	`getCodec()` Returns symbol codec used in this scheme.
`default String`	`getDigest()` Returns digest of the scheme.
`DataRecord`	`getRecord(int index)` Returns data record by its index within this scheme.
`int`	`getRecordCount()` Returns number of records in this scheme.
`<T> T`	`getService(Class<T> service_class)` Extension point for additional scheme-specific services.

- Method Detail
  - getCodec
```
SymbolCodec getCodec()
```
    Returns symbol codec used in this scheme.
  - getRecordCount
```
int getRecordCount()
```
    Returns number of records in this scheme.
  - getRecord
```
DataRecord getRecord(int index)
```
    Returns data record by its index within this scheme. The record index in the scheme coincides with its identifier and is also used for identification of data record in serialized form.
    
    Throws:
    
    IndexOutOfBoundsException - if the index is out of range (index < 0 || index >= getRecordCount()).
  - findRecordByName
```
DataRecord findRecordByName(String name)
```
    Returns data record by its name. Returns null if no such records exists.
  - findIntFieldByName
```
DataIntField findIntFieldByName(String name)
```
    Deprecated. Find record using findRecordByName(String) and find its field using DataRecord.findFieldByName(String).
    
    Returns Int-field by its full name. Returns null if no such fields exists.
  - findObjFieldByName
```
DataObjField findObjFieldByName(String name)
```
    Deprecated. Find record using findRecordByName(String) and find its field using DataRecord.findFieldByName(String).
    
    Returns Obj-field by its full name. Returns null if no such fields exists.
  - getService
```
<T> T getService(Class<T> service_class)
```
    Extension point for additional scheme-specific services. The following services are now supported:
    This method returns null if no scheme-specific override for the corresponding service is found.
    Default implementation in DefaultScheme is to use Services.createService(java.lang.Class<T>, java.lang.ClassLoader, java.lang.String) with this scheme's class loader.
  - getDigest
```
default String getDigest()
```
    Returns digest of the scheme.
    Returns null by default.
    
    Returns:
    
    Digest of the scheme.

Interface DataScheme

Method Summary

Method Detail

getCodec

getRecordCount

getRecord

findRecordByName

findIntFieldByName

findObjFieldByName

getService

getDigest