com.vaadin.flow.internal

Class JsonCodec

java.lang.Object

com.vaadin.flow.internal.JsonCodec

public class JsonCodec
extends Object

Utility for encoding objects to and from JSON.

Supported types are

• String
• Boolean and boolean
• Integer and int
• Double and double (NaN and infinity not supported)
• JsonValue and all its sub types
• Element (encoded as a reference to the element)
• Component (encoded as a reference to the root element)

Since:

1.0

Author:

Vaadin Ltd

Field Summary

Fields

Modifier and Type	Field and Description
static int	ARRAY_TYPE Type id for a complex type array containing a JsonArray.
static int	NODE_TYPE Type id for a complex type array containing an Element.
static int	RETURN_CHANNEL_TYPE Type id for a complex type array identifying a ReturnChannelRegistration reference.

Method Summary

Modifier and Type	Method and Description
static boolean	canEncodeWithoutTypeInfo(Class<?> type) Helper for checking whether the type is supported by encodeWithoutTypeInfo(Object).
static boolean	canEncodeWithTypeInfo(Class<?> type) Helper for checking whether the type is supported by encodeWithTypeInfo(Object).
static <T> T	decodeAs(elemental.json.JsonValue json, Class<T> type) Decodes the given JSON value as the given type.
static Serializable	decodeWithoutTypeInfo(elemental.json.JsonValue json) Helper for decoding any "primitive" value that is directly supported in JSON.
static elemental.json.JsonValue	encodeWithConstantPool(Object value, ConstantPool constantPool) Encodes a "primitive" value or a constant pool reference to JSON.
static elemental.json.JsonValue	encodeWithoutTypeInfo(Object value) Helper for encoding any "primitive" value that is directly supported in JSON.
static elemental.json.JsonValue	encodeWithTypeInfo(Object value) Helper for encoding values that might not have a native representation in JSON.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NODE_TYPE

public static final int NODE_TYPE

Type id for a complex type array containing an Element.

See Also:

Constant Field Values

ARRAY_TYPE

public static final int ARRAY_TYPE

Type id for a complex type array containing a JsonArray.

See Also:

Constant Field Values

RETURN_CHANNEL_TYPE

public static final int RETURN_CHANNEL_TYPE

Type id for a complex type array identifying a ReturnChannelRegistration reference.

See Also:

Constant Field Values

Method Detail

encodeWithTypeInfo

public static elemental.json.JsonValue encodeWithTypeInfo(Object value)

Helper for encoding values that might not have a native representation in JSON. Such types are encoded as an JSON array starting with an id defining the actual type and followed by the actual data. Supported value types are any native JSON type supported by encodeWithoutTypeInfo(Object), Element and Component (encoded as its root element).

Parameters:

value - the value to encode

Returns:

the value encoded as JSON

canEncodeWithoutTypeInfo

public static boolean canEncodeWithoutTypeInfo(Class<?> type)

Helper for checking whether the type is supported by encodeWithoutTypeInfo(Object). Supported value types are String, Integer, Double, Boolean, JsonValue.

Parameters:

type - the type to check

Returns:

whether the type can be encoded

canEncodeWithTypeInfo

public static boolean canEncodeWithTypeInfo(Class<?> type)

Helper for checking whether the type is supported by encodeWithTypeInfo(Object). Supported values types are Node, Component, ReturnChannelRegistration and anything accepted by canEncodeWithoutTypeInfo(Class).

Parameters:

type - the type to check

Returns:

whether the type can be encoded

encodeWithConstantPool

public static elemental.json.JsonValue encodeWithConstantPool(Object value,
                                                              ConstantPool constantPool)

Encodes a "primitive" value or a constant pool reference to JSON. This methods supports ConstantPoolKey in addition to the types supported by encodeWithoutTypeInfo(Object).

Parameters:

value - the value to encode

constantPool - the constant pool to use for encoding constant pool references

Returns:

the value encoded as JSON

encodeWithoutTypeInfo

public static elemental.json.JsonValue encodeWithoutTypeInfo(Object value)

Helper for encoding any "primitive" value that is directly supported in JSON. Supported values types are String, Number, Boolean, JsonValue. null is also supported.

Parameters:

value - the value to encode

Returns:

the value encoded as JSON

decodeWithoutTypeInfo

public static Serializable decodeWithoutTypeInfo(elemental.json.JsonValue json)

Helper for decoding any "primitive" value that is directly supported in JSON. Supported values types are String, Number, Boolean, JsonValue. null is also supported.

Parameters:

json - the JSON value to decode

Returns:

the decoded value

decodeAs

public static <T> T decodeAs(elemental.json.JsonValue json,
                             Class<T> type)

Decodes the given JSON value as the given type.

Supported types are String, Boolean, Integer, Double and primitives boolean, int, double

Type Parameters:

T - the decoded type

Parameters:

json - the JSON value

type - the type to decode as

Returns:

the value decoded as the given type

Throws:

IllegalArgumentException - if the type was unsupported