Codec

Type Parameters:: T - desired resulting type

public interface Codec<T>

Codec instances are used to convert a Value to a concrete type. There are pre-defined codecs for each FaunaDB primitive types. Each Codec implementation returns a Result instance for the conversion attempt. If the conversion attempt fails, the Result instance will contain an error message. Custom codecs can be created by implementing the Codec interface.

Example:


 class User {
   static final Codec<User> USER_CODEC = new Codec<User>() {
     public Result<User> decode(Value value) {
       return Result.success(new User(
         value.at("username").to(String.class).getOrElse("<no name>"),
         value.at("password").to(String.class).getOrElse(null)
       ));
     }

     public Result<Value> encode(User user) {
       return Value.from(ImmutableMap.of(
         "username", user.username,
         "password", person.password
       ));
     }
   }

   final String username, password;

   Person(String username, String password) {
     this.firstName = firstName;
     this.lastName = lastName;
   }
 }

 //...
 Value result = client.query(getUser).get();
 Result<User> user = result.at("data").to(User.USER_CODEC);

It is possible to annotate classes and let the internal framework encode/decode instances of the class automatically.

Refer to the annotations FaunaField, FaunaConstructor, FaunaIgnore and FaunaEnum for more details.

See Also:: FaunaField, FaunaConstructor, FaunaEnum, FaunaIgnore, Encoder, Decoder, Language.Value(Object), Result

Field Summary

Fields
Modifier and Type	Field and Description
`static Codec<java.util.List<Value>>`	`ARRAY` Converts a `Value` to an `List` of `Value`
`static Codec<java.lang.Boolean>`	`BOOLEAN` Converts a `Value` to a `Boolean`
`static Codec<java.lang.Byte>`	`BYTE` Converts a `Value` to a `Byte`
`static Codec<byte[]>`	`BYTES` Converts a `Value` to an array of bytes
`static Codec<java.lang.Character>`	`CHAR` Converts a `Value` to a `Character`
`static Codec<java.time.LocalDate>`	`DATE` Converts a `Value` to a `LocalDate`
`static Codec<java.lang.Double>`	`DOUBLE` Converts a `Value` to a `Double`
`static Codec<java.lang.Float>`	`FLOAT` Converts a `Value` to a `Float`
`static Codec<java.lang.Integer>`	`INTEGER` Converts a `Value` to a `Integer`
`static Codec<java.lang.Long>`	`LONG` Converts a `Value` to a `Long`
`static Codec<java.util.Map<java.lang.String,Value>>`	`OBJECT` Converts a `Value` to a `Map` of `String` to `Value`
`static Codec<Value.RefV>`	`REF` Converts a `Value` to a `Value.RefV`
`static Codec<Value.SetRefV>`	`SET_REF` Converts a `Value` to a `Value.SetRefV`
`static Codec<java.lang.Short>`	`SHORT` Converts a `Value` to a `Short`
`static Codec<java.lang.String>`	`STRING` Converts a `Value` to a `String`
`static Codec<java.time.Instant>`	`TIME` Converts a `Value` to an `Instant`
`static Codec<Value>`	`VALUE` Convert a `Value` to itself.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type Method and Description

Result<T> decode(Value value)

Result<Value> encode(T value)

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`Result<T>`	`decode(Value value)`
`Result<Value>`	`encode(T value)`

Field Detail

VALUE
```
static final Codec<Value> VALUE
```
Convert a Value to itself. Returns a failed Result if null.

REF
```
static final Codec<Value.RefV> REF
```
Converts a Value to a Value.RefV

SET_REF

static final Codec<Value.SetRefV> SET_REF

Converts a Value to a Value.SetRefV

LONG

static final Codec<java.lang.Long> LONG

Converts a Value to a Long

INTEGER

static final Codec<java.lang.Integer> INTEGER

Converts a Value to a Integer

SHORT

static final Codec<java.lang.Short> SHORT

Converts a Value to a Short

BYTE

static final Codec<java.lang.Byte> BYTE

Converts a Value to a Byte

CHAR

static final Codec<java.lang.Character> CHAR

Converts a Value to a Character

TIME

static final Codec<java.time.Instant> TIME

Converts a Value to an Instant

STRING

static final Codec<java.lang.String> STRING

Converts a Value to a String

DOUBLE

static final Codec<java.lang.Double> DOUBLE

Converts a Value to a Double

FLOAT

static final Codec<java.lang.Float> FLOAT

Converts a Value to a Float

BOOLEAN

static final Codec<java.lang.Boolean> BOOLEAN

Converts a Value to a Boolean

DATE

static final Codec<java.time.LocalDate> DATE

Converts a Value to a LocalDate

ARRAY

static final Codec<java.util.List<Value>> ARRAY

Converts a Value to an List of Value

OBJECT

static final Codec<java.util.Map<java.lang.String,Value>> OBJECT

Converts a Value to a Map of String to Value

BYTES
```
static final Codec<byte[]> BYTES
```
Converts a Value to an array of bytes

Method Detail

decode
```
Result<T> decode(Value value)
```

encode
```
Result<Value> encode(T value)
```

Interface Codec<T>