public abstract class JsonValue
extends java.lang.Object
implements java.io.Serializable
The literal names true, false, and null are
represented by the constants TRUE
, FALSE
, and NULL
.
JSON objects and arrays are represented by the subtypes
JsonObject
and JsonArray
. Instances of these types can be created using the
public constructors.
Instances for JSON numbers and strings can be created using the
static factory methods valueOf(String)
, valueOf(long)
, valueOf(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 there is no doubt about the type of a JSON value, one of 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.
Modifier and Type | Field and Description |
---|---|
static JsonValue |
FALSE
Represents the JSON literal
false . |
static JsonValue |
NULL
The JSON literal
null . |
static JsonValue |
TRUE
Represents the JSON literal
true . |
Modifier and Type | Method and Description |
---|---|
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. |
java.lang.String |
asString()
Returns this JSON value as String, assuming that this value represents a JSON string.
|
boolean |
equals(java.lang.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 . |
static JsonValue |
readFrom(java.io.Reader reader)
Reads a JSON value from the given reader.
|
static JsonValue |
readFrom(java.lang.String text)
Reads a JSON value from the given string.
|
java.lang.String |
toString()
Returns the JSON string for this value in its minimal form, without any additional whitespace.
|
static JsonValue |
valueOf(boolean value)
Returns a JsonValue instance that represents the given
boolean value. |
static JsonValue |
valueOf(double value)
Returns a JsonValue instance that represents the given
double value. |
static JsonValue |
valueOf(float value)
Returns a JsonValue instance that represents the given
float value. |
static JsonValue |
valueOf(int value)
Returns a JsonValue instance that represents the given
int value. |
static JsonValue |
valueOf(long value)
Returns a JsonValue instance that represents the given
long value. |
static JsonValue |
valueOf(java.lang.String string)
Returns a JsonValue instance that represents the given string.
|
protected abstract void |
write(org.eclipse.rap.json.JsonWriter writer) |
void |
writeTo(java.io.Writer writer)
Writes the JSON representation for this object to the given writer.
|
public static final JsonValue TRUE
true
.public static final JsonValue FALSE
false
.public static final JsonValue NULL
null
.public static JsonValue readFrom(java.io.Reader reader) throws java.io.IOException
Characters are read in chunks and buffered internally, therefore wrapping an existing reader in
an additional BufferedReader
does not improve reading
performance.
reader
- the reader to read the JSON value fromjava.io.IOException
- if an I/O error occurs in the readerParseException
- if the input is not valid JSONpublic static JsonValue readFrom(java.lang.String text)
text
- the string that contains the JSON valueParseException
- if the input is not valid JSONpublic static JsonValue valueOf(int value)
int
value.value
- the value to get a JSON representation forpublic static JsonValue valueOf(long value)
long
value.value
- the value to get a JSON representation forpublic static JsonValue valueOf(float value)
float
value.value
- the value to get a JSON representation forpublic static JsonValue valueOf(double value)
double
value.value
- the value to get a JSON representation forpublic static JsonValue valueOf(java.lang.String string)
string
- the string to get a JSON representation forpublic static JsonValue valueOf(boolean value)
boolean
value.value
- the value to get a JSON representation forpublic boolean isObject()
JsonObject
.true
if this value is an instance of JsonObjectpublic boolean isArray()
JsonArray
.true
if this value is an instance of JsonArraypublic boolean isNumber()
true
if this value represents a JSON numberpublic boolean isString()
true
if this value represents a JSON stringpublic boolean isBoolean()
true
if this value represents either the JSON literal
true
or false
public boolean isTrue()
true
.true
if this value represents the JSON literal
true
public boolean isFalse()
false
.true
if this value represents the JSON literal
false
public boolean isNull()
null
.true
if this value represents the JSON literal
null
public JsonObject asObject()
JsonObject
, assuming that this value represents a JSON
object. If this is not the case, an exception is thrown.java.lang.UnsupportedOperationException
- if this value is not a JSON objectpublic JsonArray asArray()
JsonArray
, assuming that this value represents a JSON
array. If this is not the case, an exception is thrown.java.lang.UnsupportedOperationException
- if this value is not a JSON arraypublic int asInt()
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.
int
java.lang.UnsupportedOperationException
- if this value is not a JSON numberjava.lang.NumberFormatException
- if this JSON number can not be interpreted as int
valuepublic long asLong()
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.
long
java.lang.UnsupportedOperationException
- if this value is not a JSON numberjava.lang.NumberFormatException
- if this JSON number can not be interpreted as long
valuepublic float asFloat()
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.
float
java.lang.UnsupportedOperationException
- if this value is not a JSON numberpublic double asDouble()
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.
double
java.lang.UnsupportedOperationException
- if this value is not a JSON numberpublic java.lang.String asString()
java.lang.UnsupportedOperationException
- if this value is not a JSON stringpublic boolean asBoolean()
boolean
value, assuming that this value is either
true
or false
. If this is not the case, an exception is thrown.boolean
java.lang.UnsupportedOperationException
- if this value is neither true
or false
public void writeTo(java.io.Writer writer) throws java.io.IOException
Single elements are passed directly to the given writer. Therefore, if the writer is not
buffered, wrapping it in a BufferedWriter
can drastically
improve writing performance.
writer
- the writer to write this value tojava.io.IOException
- if an I/O error occurs in the writerpublic java.lang.String toString()
readFrom(String)
and to
create a value that is equal to this object.toString
in class java.lang.Object
public boolean equals(java.lang.Object object)
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.
equals
in class java.lang.Object
object
- the reference object with which to comparepublic int hashCode()
hashCode
in class java.lang.Object
protected abstract void write(org.eclipse.rap.json.JsonWriter writer) throws java.io.IOException
java.io.IOException
Copyright (c) EclipseSource and others 2002, 2017.
All rights reserved. This program and the accompanying materials
are made available under the terms of the
Eclipse Public License v1.0