Package com.restfb.json

Klasse JsonValue

java.lang.Object

com.restfb.json.JsonValue

Alle implementierten Schnittstellen:

Serializable

Bekannte direkte Unterklassen:

JsonArray, JsonObject

public abstract class JsonValue
extends Object
implements Serializable

Represents a JSON value. This can be a JSON object, an array, a number, a string, or one of the literals true, false, and null.

The literals true, false, and null are represented by the constants Json.TRUE, Json.FALSE, and Json.NULL.

JSON objects and arrays are represented by the subtypes JsonObject and JsonArray. Instances of these types can be created using the public constructors of these classes.

Instances that represent JSON numbers, strings and boolean values can be created using the static factory methods Json.value(String), Json.value(long), Json.value(double), etc.

In order to find out whether an instance of this class is of a certain type, the methods isObject(), isArray(), isString(), isNumber() etc. can be used.

If the type of a JSON value is known, the methods asObject(), asArray(), asString(), asInt(), etc. can be used to get this value directly in the appropriate target type.

This class is not supposed to be extended by clients.

Siehe auch:

• Serialisierte Form

Feldübersicht

Felder

Modifizierer und Typ	Feld	Beschreibung
protected static final String	ARRAY_IS_NULL
protected static final String	NAME_IS_NULL
protected static final String	OBJECT_IS_NULL
protected static final String	STRING_IS_NULL
protected static final String	VALUE_IS_NULL

Methodenübersicht

Modifizierer und Typ	Methode	Beschreibung
JsonArray	asArray()	Returns this JSON value as JsonArray, assuming that this value represents a JSON array.
boolean	asBoolean()	Returns this JSON value as a boolean value, assuming that this value is either true or false.
double	asDouble()	Returns this JSON value as a double value, assuming that this value represents a JSON number.
float	asFloat()	Returns this JSON value as a float value, assuming that this value represents a JSON number.
int	asInt()	Returns this JSON value as an int value, assuming that this value represents a JSON number that can be interpreted as Java int.
long	asLong()	Returns this JSON value as a long value, assuming that this value represents a JSON number that can be interpreted as Java long.
JsonObject	asObject()	Returns this JSON value as JsonObject, assuming that this value represents a JSON object.
String	asString()	Returns this JSON value as String, assuming that this value represents a JSON string.
boolean	equals(Object object)	Indicates whether some other object is "equal to" this one according to the contract specified in Object.equals(Object).
int	hashCode()
boolean	isArray()	Detects whether this value represents a JSON array.
boolean	isBoolean()	Detects whether this value represents a boolean value.
boolean	isFalse()	Detects whether this value represents the JSON literal false.
boolean	isNull()	Detects whether this value represents the JSON literal null.
boolean	isNumber()	Detects whether this value represents a JSON number.
boolean	isObject()	Detects whether this value represents a JSON object.
boolean	isString()	Detects whether this value represents a JSON string.
boolean	isTrue()	Detects whether this value represents the JSON literal true.
String	toString()	Returns the JSON string for this value in its minimal form, without any additional whitespace.
String	toString(WriterConfig config)	Returns the JSON string for this value using the given formatting.
void	writeTo(Writer writer)	Writes the JSON representation of this value to the given writer in its minimal form, without any additional whitespace.
void	writeTo(Writer writer, WriterConfig config)	Writes the JSON representation of this value to the given writer using the given formatting.

Von Klasse geerbte Methoden java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Felddetails

STRING_IS_NULL

protected static final String STRING_IS_NULL

Siehe auch:

• Konstantenfeldwerte

OBJECT_IS_NULL

protected static final String OBJECT_IS_NULL

Siehe auch:

• Konstantenfeldwerte

NAME_IS_NULL

protected static final String NAME_IS_NULL

Siehe auch:

• Konstantenfeldwerte

VALUE_IS_NULL

protected static final String VALUE_IS_NULL

Siehe auch:

• Konstantenfeldwerte

ARRAY_IS_NULL

protected static final String ARRAY_IS_NULL

Siehe auch:

• Konstantenfeldwerte

Methodendetails

isObject

public boolean isObject()

Detects whether this value represents a JSON object. If this is the case, this value is an instance of JsonObject.

Gibt zurück:

true if this value is an instance of JsonObject

isArray

public boolean isArray()

Detects whether this value represents a JSON array. If this is the case, this value is an instance of JsonArray.

Gibt zurück:

true if this value is an instance of JsonArray

isNumber

public boolean isNumber()

Detects whether this value represents a JSON number.

Gibt zurück:

true if this value represents a JSON number

isString

public boolean isString()

Detects whether this value represents a JSON string.

Gibt zurück:

true if this value represents a JSON string

isBoolean

public boolean isBoolean()

Detects whether this value represents a boolean value.

Gibt zurück:

true if this value represents either the JSON literal true or false

isTrue

public boolean isTrue()

Detects whether this value represents the JSON literal true.

Gibt zurück:

true if this value represents the JSON literal true

isFalse

public boolean isFalse()

Detects whether this value represents the JSON literal false.

Gibt zurück:

true if this value represents the JSON literal false

isNull

public boolean isNull()

Detects whether this value represents the JSON literal null.

Gibt zurück:

true if this value represents the JSON literal null

asObject

public JsonObject asObject()

Returns this JSON value as JsonObject, assuming that this value represents a JSON object. If this is not the case, an exception is thrown.

Gibt zurück:

a JSONObject for this value

Löst aus:

UnsupportedOperationException - if this value is not a JSON object

asArray

public JsonArray asArray()

Returns this JSON value as JsonArray, assuming that this value represents a JSON array. If this is not the case, an exception is thrown.

Gibt zurück:

a JSONArray for this value

Löst aus:

UnsupportedOperationException - if this value is not a JSON array

asInt

public int asInt()

Returns this JSON value as an int value, assuming that this value represents a JSON number that can be interpreted as Java int. If this is not the case, an exception is thrown.

To be interpreted as Java int, the JSON number must neither contain an exponent nor a fraction part. Moreover, the number must be in the Integer range.

Gibt zurück:

this value as int

Löst aus:

UnsupportedOperationException - if this value is not a JSON number

NumberFormatException - if this JSON number can not be interpreted as int value

asLong

public long asLong()

Returns this JSON value as a long value, assuming that this value represents a JSON number that can be interpreted as Java long. If this is not the case, an exception is thrown.

To be interpreted as Java long, the JSON number must neither contain an exponent nor a fraction part. Moreover, the number must be in the Long range.

Gibt zurück:

this value as long

Löst aus:

UnsupportedOperationException - if this value is not a JSON number

NumberFormatException - if this JSON number can not be interpreted as long value

asFloat

public float asFloat()

Returns this JSON value as a float value, assuming that this value represents a JSON number. If this is not the case, an exception is thrown.

If the JSON number is out of the Float range, Float.POSITIVE_INFINITY or Float.NEGATIVE_INFINITY is returned.

Gibt zurück:

this value as float

Löst aus:

UnsupportedOperationException - if this value is not a JSON number

asDouble

public double asDouble()

Returns this JSON value as a double value, assuming that this value represents a JSON number. If this is not the case, an exception is thrown.

If the JSON number is out of the Double range, Double.POSITIVE_INFINITY or Double.NEGATIVE_INFINITY is returned.

Gibt zurück:

this value as double

Löst aus:

UnsupportedOperationException - if this value is not a JSON number

asString

public String asString()

Returns this JSON value as String, assuming that this value represents a JSON string. If this is not the case, an exception is thrown.

Gibt zurück:

the string represented by this value

Löst aus:

UnsupportedOperationException - if this value is not a JSON string

asBoolean

public boolean asBoolean()

Returns this JSON value as a boolean value, assuming that this value is either true or false. If this is not the case, an exception is thrown.

Gibt zurück:

this value as boolean

Löst aus:

UnsupportedOperationException - if this value is neither true or false

writeTo

public void writeTo(Writer writer)
             throws IOException

Writes the JSON representation of this value to the given writer in its minimal form, without any additional whitespace.

Writing performance can be improved by using a BufferedWriter.

Parameter:

writer - the writer to write this value to

Löst aus:

IOException - if an I/O error occurs in the writer

writeTo

public void writeTo(Writer writer,
 WriterConfig config)
             throws IOException

Writes the JSON representation of this value to the given writer using the given formatting.

Writing performance can be improved by using a BufferedWriter.

Parameter:

writer - the writer to write this value to

config - a configuration that controls the formatting or null for the minimal form

Löst aus:

IOException - if an I/O error occurs in the writer

toString

public String toString()

Returns the JSON string for this value in its minimal form, without any additional whitespace. The result is guaranteed to be a valid input for the method Json.parse(String) and to create a value that is equal to this object.

Setzt außer Kraft:

toString in Klasse Object

Gibt zurück:

a JSON string that represents this value

toString

public String toString(WriterConfig config)

Returns the JSON string for this value using the given formatting.

Parameter:

config - a configuration that controls the formatting or null for the minimal form

Gibt zurück:

a JSON string that represents this value

equals

public boolean equals(Object object)

Indicates whether some other object is "equal to" this one according to the contract specified in Object.equals(Object).

Two JsonValues are considered equal if and only if they represent the same JSON text. As a consequence, two given JsonObjects may be different even though they contain the same set of names with the same values, but in a different order.

Setzt außer Kraft:

equals in Klasse Object

Parameter:

object - the reference object with which to compare

Gibt zurück:

true if this object is the same as the object argument; false otherwise

hashCode

public int hashCode()

Setzt außer Kraft:

hashCode in Klasse Object