- org.apache.tapestry5.json.JSONCollection
- - org.apache.tapestry5.json.JSONObject

All Implemented Interfaces:

, <,>
```
public final class JSONObject
extends JSONCollection
implements <,>
```
A modifiable set of name/value mappings. Names are unique, non-null strings. Values may be any mix of JSONObjects, JSONArrays, Strings, Booleans, Integers, Longs, Doubles or NULL. Values may not be null, , , or of any type not listed here.
This class can coerce values to another type when requested.
- When the requested type is a boolean, strings will be coerced using a case-insensitive comparison to "true" and "false".
- When the requested type is a double, other types will be coerced using . Strings that can be coerced using will be.
- When the requested type is an int, other types will be coerced using . Strings that can be coerced using will be, and then cast to int.
- types will be coerced using . Strings that can be coerced using will be, and then cast to long. This two-step conversion is lossy for very large values. For example, the string "9223372036854775806" yields the long 9223372036854775807.
- When the requested type is a String, other non-null values will be coerced using . Although null cannot be coerced, the sentinel value NULL is coerced to the string "null".
This class can look up both mandatory and optional values:
- Use getType() to retrieve a mandatory value. This fails with a RuntimeException if the requested name has no value or if the value cannot be coerced to the requested type.
- Use opt() to retrieve an optional value.
Warning: this class represents null in two incompatible ways: the standard Java null reference, and the sentinel value NULL. In particular, calling put(name, null) removes the named entry from the object but put(name, JSONObject.NULL) stores an entry whose value is JSONObject.NULL.
Instances of this class are not thread safe.
See Also:

Serialized Form

Nested Class Summary
- Nested classes/interfaces inherited from interface java.util.
  < extends , extends >

Field Summary

Fields
Modifier and Type Field Description

static NULL
A sentinel value used to explicitly define a name with no value.

Constructor Summary

Constructors
Constructor	Description
`JSONObject()`	Creates a `JSONObject` with no name/value mappings.
`... keysAndValues)`	Constructs a new JSONObject using a series of String keys and object values.
`json)`	Creates a new `JSONObject` with name/value mappings from the JSON string.
`JSONObject(JSONObject copyFrom, ... names)`	Creates a new `JSONObject` by copying mappings for the listed names from the given object.

Method Summary

All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`JSONObject`	`name, value)`	Appends `value` to the array already mapped to `name`.
`JSONObject`	`name, value)`	Appends values to the array mapped to `name`.
`void`	`clear()`	Removes all of the mappings from this JSONObject.
`boolean`	`key)`	Returns `true` if this JSONObject contains a mapping for the specified key.
`boolean`	`value)`	Returns `true` if this JSONObject maps one or more keys to the specified value.
`JSONObject`	`copy()`	Returns a new JSONObject that is a shallow copy of this JSONObject.
`<<,>>`	`entrySet()`	Returns a view of the mappings contained in this JSONObject.
`boolean`	`obj)`
	`name)`	Returns the value mapped by `name`, or throws if no such mapping exists.
`boolean`	`name)`	Returns the value mapped by `name` if it exists and is a boolean or can be coerced to a boolean, or throws otherwise.
`boolean`	`name, boolean defaultValue)`	Returns the value to which the specified key is mapped and a boolean, or `defaultValue` if this JSONObject contains no mapping for the key.
`double`	`name)`	Returns the value mapped by `name` if it exists and is a double or can be coerced to a double, or throws otherwise.
`int`	`name)`	Returns the value mapped by `name` if it exists and is an int or can be coerced to an int, or throws otherwise.
`int`	`name, int defaultValue)`	Returns the value to which the specified key is mapped and an int, or `defaultValue` if this JSONObject contains no mapping for the key.
`JSONArray`	`name)`	Returns the value mapped by `name` if it exists and is a `JSONArray`, or throws otherwise.
`JSONArray`	`name, JSONArray defaultValue)`	Returns the value to which the specified key is mapped and a JSONArray, or `defaultValue` if this JSONObject contains no mapping for the key.
`JSONObject`	`name)`	Returns the value mapped by `name` if it exists and is a `JSONObject`, or throws otherwise.
`JSONObject`	`name, JSONObject defaultValue)`	Returns the value to which the specified key is mapped and a JSONObject, or `defaultValue` if this map contains no mapping for the key.
`long`	`name)`	Returns the value mapped by `name` if it exists and is a long or can be coerced to a long, or throws otherwise.
`long`	`name, int defaultValue)`	Returns the value to which the specified key is mapped and a long, or `defaultValue` if this JSONObject contains no mapping for the key.
	`key, defaultValue)`	Returns the value to which the specified key is mapped, or `defaultValue` if this JSONObject contains no mapping for the key.
	`name)`	Returns the value mapped by `name` if it exists, coercing it if necessary, or throws if no such mapping exists.
	`name, defaultValue)`	Returns the value to which the specified key is mapped and a string, or `defaultValue` if this JSONObject contains no mapping for the key.
`boolean`	`name)`	Deprecated. use `containsKey(Object)` instead
`JSONObject`	`key)`	Navigates into a nested JSONObject, creating the JSONObject if necessary.
`boolean`	`isEmpty()`	Returns `true` if this JSONObject contains no key-value mappings.
`boolean`	`name)`	Returns true if this object has no mapping for `name` or if it has a mapping whose value is `NULL`.
`<>`	`keys()`	Returns the set of `String` names in this object.
`<>`	`keySet()`	Returns a view of the keys contained in this JSONObject.
`int`	`length()`	Deprecated. Use `size()` instead.
	`key, value, <? super ,? super ,? extends > remappingFunction)`	If the specified key is not already associated with a value or is associated with null, associates it with the given non-null value.
`JSONArray`	`names()`	Returns an array containing the string names in this object.
`static`	`number)`	Encodes the number as a JSON string.
	`name)`	Returns the value mapped by `name`, or null if no such mapping exists.
`JSONObject`	`name, value)`	Maps `name` to `value`, clobbering any existing name/value mapping with the same name.
`void`	`<? extends ,? extends > newProperties)`	Invokes `put(String, Object)` for each value from the map.
`static`	`data)`	Encodes `data` as a JSON string.
	`name)`	Removes the named mapping if it exists; does nothing otherwise.
`int`	`size()`	Returns the number of key-value mappings in this JSONObject.
`<,>`	`toMap()`	Returns a Map of the keys and values of the JSONObject.
`<>`	`values()`	Returns a view of the values contained in this JSONObject.

Methods inherited from class org.apache.tapestry5.json.JSONCollection
prettyPrint, print, print, toCompactString, toString, toString

Methods inherited from class java.lang.
, , , , , , , ,

Methods inherited from interface java.util.
, , , , , , , , ,

- Field Detail
  - NULL
```
public static final  NULL
```
    A sentinel value used to explicitly define a name with no value. Unlike null, names with this value:
    
    show up in the names() array
    show up in the keys() iterator
    return true for has(String)
    do not throw on get(java.lang.Object)
    are included in the encoded JSON string.
    
    This value violates the general contract of by returning true when compared to null. Its JSONCollection.toString() method returns "null".
- Constructor Detail
  - JSONObject
```
public JSONObject()
```
    Creates a JSONObject with no name/value mappings.
  - JSONObject
```
public  json)
```
    Creates a new JSONObject with name/value mappings from the JSON string.
    
    Parameters:
    
    json - a JSON-encoded string containing an object.
    
    Throws:
    
    - if the parse fails or doesn't yield a JSONObject.
  - JSONObject
```
public JSONObject(JSONObject copyFrom,
                  ... names)
```
    Creates a new JSONObject by copying mappings for the listed names from the given object. Names that aren't present in copyFrom will be skipped.
    
    Parameters:
    
    copyFrom - The source object.
    
    names - The names of the fields to copy.
    
    Throws:
    
    - On internal errors. Shouldn't happen.
  - JSONObject
```
public ... keysAndValues)
```
    Constructs a new JSONObject using a series of String keys and object values. Object values should be compatible with put(String, Object). Keys must be strings (toString() will be invoked on each key). Prior to release 5.4, keysAndValues was type String...; changing it to Object... makes it much easier to initialize a JSONObject in a single statement, which is more readable.
    
    Since:
    
    5.2.0
- Method Detail
  - copy
```
public JSONObject copy()
```
    Returns a new JSONObject that is a shallow copy of this JSONObject.
    
    Since:
    
    5.4
  - length
```
public int length()
```
    Deprecated.
    Use size() instead.
    
    Returns the number of name/value mappings in this object.
    
    Returns:
    
    the length of this.
  - put
```
public  name,
                       value)
```
    Maps name to value, clobbering any existing name/value mapping with the same name. If the value is null, any existing mapping for name is removed.
    
    Specified by:
    
    in interface <,>
    
    Parameters:
    
    name - The name of the new value.
    
    value - a JSONObject, JSONArray, String, Boolean, Integer, Long, Double, NULL, or null. May not be or .
    
    Returns:
    
    this object.
    
    Throws:
    
    - if the value is an invalid double (infinite or NaN).
  - accumulate
```
public  name,
                              value)
```
    Appends value to the array already mapped to name. If this object has no mapping for name, this inserts a new mapping. If the mapping exists but its value is not an array, the existing and new values are inserted in order into a new array which is itself mapped to name. In aggregate, this allows values to be added to a mapping one at a time. Note that append(String, Object) provides better semantics. In particular, the mapping for name will always be a JSONArray. Using accumulate will result in either a JSONArray or a mapping whose type is the type of value depending on the number of calls to it.
    
    Parameters:
    
    name - The name of the field to change.
    
    value - a JSONObject, JSONArray, String, Boolean, Integer, Long, Double, or .
    
    Returns:
    
    this object after mutation.
    
    Throws:
    
    - If the object being added is an invalid number.
  - append
```
public  name,
                          value)
```
    Appends values to the array mapped to name. A new JSONArray mapping for name will be inserted if no mapping exists. If the existing mapping for name is not a will be thrown.
    
    Parameters:
    
    name - The name of the array to which the value should be appended.
    
    value - The value to append.
    
    Returns:
    
    this object.
    
    Throws:
    
    JSONTypeMismatchException - if name is null or if the mapping for name is non-null and is not a JSONArray.
  - isNull
```
public boolean  name)
```
    Returns true if this object has no mapping for name or if it has a mapping whose value is NULL.
    
    Parameters:
    
    name - The name of the value to check on.
    
    Returns:
    
    true if the field doesn't exist or is null.
  - has
```
public boolean  name)
```
    Deprecated.
    use containsKey(Object) instead
    
    Returns true if this object has a mapping for name. The mapping may be NULL.
    
    Parameters:
    
    name - The name of the value to check on.
    
    Returns:
    
    true if this object has a field named name
  - opt
```
public   name)
```
    Returns the value mapped by name, or null if no such mapping exists.
    
    Parameters:
    
    name - The name of the value to get.
    
    Returns:
    
    The value.
  - getBoolean
```
public boolean  name)
```
    Returns the value mapped by name if it exists and is a boolean or can be coerced to a boolean, or throws otherwise.
    
    Parameters:
    
    name - The name of the field we want.
    
    Returns:
    
    The selected value if it exists.
    
    Throws:
    
    JSONValueNotFoundException - if the mapping doesn't exist
    
    JSONTypeMismatchException - if the mapping cannot be coerced to a boolean.
  - getBooleanOrDefault
```
public boolean  name,
                                   boolean defaultValue)
```
    Returns the value to which the specified key is mapped and a boolean, or defaultValue if this JSONObject contains no mapping for the key.
    
    Parameters:
    
    name - the key whose associated value is to be returned
    
    defaultValue - the default mapping of the key
    
    Returns:
    
    the value to which the specified key is mapped, or defaultValue if this JSONObject contains no mapping for the key
    
    Throws:
    
    JSONTypeMismatchException - if the mapping cannot be coerced to a boolean.
    
    Since:
    
    5.7
  - getDouble
```
public double  name)
```
    Returns the value mapped by name if it exists and is a double or can be coerced to a double, or throws otherwise.
    
    Parameters:
    
    name - The name of the field we want.
    
    Returns:
    
    The selected value if it exists.
    
    Throws:
    
    JSONValueNotFoundException - if the mapping doesn't exist
    
    JSONTypeMismatchException - if the mapping cannot be coerced to a double.
  - getInt
```
public int  name)
```
    Returns the value mapped by name if it exists and is an int or can be coerced to an int, or throws otherwise.
    
    Parameters:
    
    name - The name of the field we want.
    
    Returns:
    
    The selected value if it exists.
    
    Throws:
    
    JSONValueNotFoundException - if the mapping doesn't exist
    
    JSONTypeMismatchException - if the mapping cannot be coerced to an int.
  - getIntOrDefault
```
public int  name,
                           int defaultValue)
```
    Returns the value to which the specified key is mapped and an int, or defaultValue if this JSONObject contains no mapping for the key.
    
    Parameters:
    
    name - the key whose associated value is to be returned
    
    defaultValue - the default mapping of the key
    
    Returns:
    
    the value to which the specified key is mapped, or defaultValue if this JSONObject contains no mapping for the key
    
    Throws:
    
    JSONTypeMismatchException - if the mapping cannot be coerced to an int.
    
    Since:
    
    5.7
  - getLong
```
public long  name)
```
    Returns the value mapped by name if it exists and is a long or can be coerced to a long, or throws otherwise. Note that JSON represents numbers as doubles, so this is lossy; use strings to transfer numbers via JSON without loss.
    
    Parameters:
    
    name - The name of the field that we want.
    
    Returns:
    
    The value of the field.
    
    Throws:
    
    JSONValueNotFoundException - if the mapping doesn't exist
    
    JSONTypeMismatchException - if the mapping cannot be coerced to a long.
  - getLongOrDefault
```
public long  name,
                             int defaultValue)
```
    Returns the value to which the specified key is mapped and a long, or defaultValue if this JSONObject contains no mapping for the key.
    
    Parameters:
    
    name - the key whose associated value is to be returned
    
    defaultValue - the default mapping of the key
    
    Returns:
    
    the value to which the specified key is mapped, or defaultValue if this JSONObject contains no mapping for the key
    
    Throws:
    
    JSONTypeMismatchException - if the mapping cannot be coerced to a long.
    
    Since:
    
    5.7
  - getString
```
public   name)
```
    Returns the value mapped by name if it exists, coercing it if necessary, or throws if no such mapping exists.
    
    Parameters:
    
    name - The name of the field we want.
    
    Returns:
    
    The value of the field.
    
    Throws:
    
    JSONValueNotFoundException - if the mapping doesn't exist
    
    JSONTypeMismatchException - if the mapping cannot be coerced to String
  - getStringOrDefault
```
public   name,
                                  defaultValue)
```
    Returns the value to which the specified key is mapped and a string, or defaultValue if this JSONObject contains no mapping for the key.
    
    Parameters:
    
    name - the key whose associated value is to be returned
    
    defaultValue - the default mapping of the key
    
    Returns:
    
    the value to which the specified key is mapped, or defaultValue if this JSONObject contains no mapping for the key
    
    Throws:
    
    JSONTypeMismatchException - if the mapping cannot be coerced to a string.
    
    Since:
    
    5.7
  - getJSONArray
```
public  name)
```
    Returns the value mapped by name if it exists and is a JSONArray, or throws otherwise.
    
    Parameters:
    
    name - The field we want to get.
    
    Returns:
    
    The value of the field (if it is a JSONArray.
    
    Throws:
    
    JSONValueNotFoundException - if the mapping doesn't exist
    
    JSONTypeMismatchException - if the mapping is not a JSONArray.
  - getJSONArrayOrDefault
```
public  name,
                                       JSONArray defaultValue)
```
    Returns the value to which the specified key is mapped and a JSONArray, or defaultValue if this JSONObject contains no mapping for the key.
    
    Parameters:
    
    name - the key whose associated value is to be returned
    
    defaultValue - the default mapping of the key
    
    Returns:
    
    the value to which the specified key is mapped, or defaultValue if this JSONObject contains no mapping for the key
    
    Throws:
    
    JSONTypeMismatchException - if the mapping cannot be coerced to a JSONArray.
    
    Since:
    
    5.7
  - getJSONObject
```
public  name)
```
    Returns the value mapped by name if it exists and is a JSONObject, or throws otherwise.
    
    Parameters:
    
    name - The name of the field that we want.
    
    Returns:
    
    a specified field value (if it is a JSONObject)
    
    Throws:
    
    JSONValueNotFoundException - if the mapping doesn't exist
    
    JSONTypeMismatchException - if the mapping is not a JSONObject.
  - getJSONObjectOrDefault
```
public  name,
                                         JSONObject defaultValue)
```
    Returns the value to which the specified key is mapped and a JSONObject, or defaultValue if this map contains no mapping for the key.
    
    Parameters:
    
    name - the key whose associated value is to be returned
    
    defaultValue - the default mapping of the key
    
    Returns:
    
    the value to which the specified key is mapped, or defaultValue if this map contains no mapping for the key
    
    Throws:
    
    JSONTypeMismatchException - if the mapping cannot be coerced to a JSONObject.
    
    Since:
    
    5.7
  - keys
```
public <> keys()
```
    Returns the set of String names in this object. The returned set is a view of the keys in this object. will remove the corresponding mapping from this object and set iterator behaviour is undefined if this object is modified after it is returned. See keys().
    
    Returns:
    
    The names in this object.
  - names
```
public JSONArray names()
```
    Returns an array containing the string names in this object. This method returns null if this object contains no mappings.
    
    Returns:
    
    the names.
  - numberToString
```
public static   number)
```
    Encodes the number as a JSON string.
    
    Parameters:
    
    number - a finite value. May not be or .
    
    Returns:
    
    The encoded number in string form.
    
    Throws:
    
    - On internal errors. Shouldn't happen.
  - quote
```
public static   data)
```
    Encodes data as a JSON string. This applies quotes and any necessary character escaping.
    
    Parameters:
    
    data - the string to encode. Null will be interpreted as an empty string.
    
    Returns:
    
    the quoted string.
  - equals
```
public boolean  obj)
```
    Specified by:
    
    in interface <,>
    
    Overrides:
    
    in class
  - toMap
```
public <,> toMap()
```
    Returns a Map of the keys and values of the JSONObject. The returned map is unmodifiable. Note that changes to the JSONObject will be reflected in the map. In addition, null values in the JSONObject are represented as NULL in the map.
    
    Returns:
    
    unmodifiable map of properties and values
    
    Since:
    
    5.4
  - in
```
public  key)
```
    Navigates into a nested JSONObject, creating the JSONObject if necessary. They key must not exist, or must be a JSONObject.
    
    Parameters:
    
    key -
    
    Returns:
    
    the nested JSONObject
    
    Throws:
    
    - if the current value for the key is not null and not JSONObject
  - size
```
public int size()
```
    Returns the number of key-value mappings in this JSONObject. If it contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.
    
    Specified by:
    
    in interface <,>
    
    Returns:
    
    the number of key-value mappings in this JSONObject
    
    Since:
    
    5.7
  - isEmpty
```
public boolean isEmpty()
```
    Returns true if this JSONObject contains no key-value mappings.
    
    Specified by:
    
    in interface <,>
    
    Returns:
    
    true if this JSONObject contains no key-value mappings
    
    Since:
    
    5.7
  - containsKey
```
public boolean  key)
```
    Returns true if this JSONObject contains a mapping for the specified key.
    
    Specified by:
    
    in interface <,>
    
    Parameters:
    
    key - key whose presence in this map is to be tested
    
    Returns:
    
    true if this map contains a mapping for the specified key
    
    Since:
    
    5.7
  - containsValue
```
public boolean  value)
```
    Returns true if this JSONObject maps one or more keys to the specified value.
    
    Specified by:
    
    in interface <,>
    
    Parameters:
    
    value - value whose presence in this map is to be tested
    
    Returns:
    
    true if this JSONObject maps one or more keys to the specified value
    
    Since:
    
    5.7
  - get
```
public   name)
```
    Returns the value mapped by name, or throws if no such mapping exists.
    
    Specified by:
    
    in interface <,>
    
    Parameters:
    
    name - The name of the value to get.
    
    Returns:
    
    The value.
    
    Throws:
    
    JSONValueNotFoundException - if no such mapping exists.
  - getOrDefault
```
public   key,
                            defaultValue)
```
    Returns the value to which the specified key is mapped, or defaultValue if this JSONObject contains no mapping for the key.
    
    Specified by:
    
    in interface <,>
    
    Parameters:
    
    key - the key whose associated value is to be returned
    
    defaultValue - the default mapping of the key
    
    Returns:
    
    the value to which the specified key is mapped, or defaultValue if this JSONObject contains no mapping for the key
    
    Since:
    
    5.7
  - remove
```
public   name)
```
    Removes the named mapping if it exists; does nothing otherwise.
    
    Specified by:
    
    in interface <,>
    
    Parameters:
    
    name - The name of the mapping to remove.
    
    Returns:
    
    the value previously mapped by name, or null if there was no such mapping.
  - putAll
```
public void <? extends ,? extends > newProperties)
```
    Invokes put(String, Object) for each value from the map.
    
    Specified by:
    
    in interface <,>
    
    Parameters:
    
    newProperties - to add to this JSONObject
    
    Since:
    
    5.7
  - clear
```
public void clear()
```
    Removes all of the mappings from this JSONObject.
    
    Specified by:
    
    in interface <,>
    
    Since:
    
    5.7
  - keySet
```
public <> keySet()
```
    Returns a view of the keys contained in this JSONObject. The set is backed by the JSONObject, so changes to the map are reflected in the set, and vice-versa.
    
    Specified by:
    
    in interface <,>
    
    Returns:
    
    a set view of the keys contained in this JSONObject
    
    Since:
    
    5.7
  - values
```
public <> values()
```
    Returns a view of the values contained in this JSONObject. The collection is backed by the JSONObject, so changes to the map are reflected in the collection, and vice-versa.
    
    Specified by:
    
    in interface <,>
    
    Returns:
    
    a collection view of the values contained in this JSONObject
    
    Since:
    
    5.7
  - entrySet
```
public <<,>> entrySet()
```
    Returns a view of the mappings contained in this JSONObject. The set is backed by the JSONObject, so changes to the map are reflected in the set, and vice-versa.
    
    Specified by:
    
    in interface <,>
    
    Returns:
    
    a set view of the mappings contained in this JSONObject
    
    Since:
    
    5.7
  - merge
```
public   key,
                     value,
                    <? super ,? super ,? extends > remappingFunction)
```
    If the specified key is not already associated with a value or is associated with null, associates it with the given non-null value. Otherwise, replaces the associated value with the results of the given remapping function, or removes if the result is null.
    
    Specified by:
    
    in interface <,>
    
    Parameters:
    
    key - key with which the resulting value is to be associated
    
    value - the non-null value to be merged with the existing value associated with the key or, if no existing value or a null value is associated with the key, to be associated with the key
    
    remappingFunction - the function to recompute a value if present
    
    Returns:
    
    the new value associated with the specified key, or null if no value is associated with the key
    
    Throws:
    
    - if the specified key is null or the value or remappingFunction is null
    
    Since:
    
    5.7

Class JSONObject

Nested Class Summary

Nested classes/interfaces inherited from interface java.util.

Field Summary

Constructor Summary

Method Summary

Methods inherited from class org.apache.tapestry5.json.JSONCollection

Methods inherited from class java.lang.

Methods inherited from interface java.util.

Field Detail

NULL

Constructor Detail

JSONObject

JSONObject

JSONObject

JSONObject

Method Detail

copy

length

put

accumulate

append

isNull

has

opt

getBoolean

getBooleanOrDefault

getDouble

getInt

getIntOrDefault

getLong

getLongOrDefault

getString

getStringOrDefault

getJSONArray

getJSONArrayOrDefault

getJSONObject

getJSONObjectOrDefault

keys

names

numberToString

quote

equals

toMap

in

size

isEmpty

containsKey

containsValue

get

getOrDefault

remove

putAll

clear

keySet

values

entrySet

merge