javax.json

Interface JsonObject

All Superinterfaces:

JsonStructure, JsonValue, Map<String,JsonValue>

public interface JsonObject
extends JsonStructure, Map<String,JsonValue>

JsonObject class represents an immutable JSON object value (an unordered collection of zero or more name/value pairs). It also provides unmodifiable map view to the JSON object name/value mappings.

A JsonObject instance can be created from an input source using JsonReader.readObject(). For example:

 JsonReader jsonReader = new JsonReader(...);
 JsonObject object = jsonReader.readObject();
 jsonReader.close();
 

It can also be built from scratch using a JsonObjectBuilder.

For example 1: An empty JSON object can be built as follows:

 JsonObject object = new JsonObjectBuilder().build();
 

For example 2: The following JSON

 {
     "firstName": "John", "lastName": "Smith", "age": 25,
     "address" : {
         "streetAddress", "21 2nd Street",
         "city", "New York",
         "state", "NY",
         "postalCode", "10021"
     },
     "phoneNumber": [
         { "type": "home", "number": "212 555-1234" },
         { "type": "fax", "number": "646 555-4567" }
     ]
 }
 

can be built using :

 JsonObject value = new JsonObjectBuilder()
     .add("firstName", "John")
     .add("lastName", "Smith")
     .add("age", 25)
     .add("address", new JsonObjectBuilder()
         .add("streetAddress", "21 2nd Street")
         .add("city", "New York")
         .add("state", "NY")
         .add("postalCode", "10021"))
     .add("phoneNumber", new JsonArrayBuilder()
         .add(new JsonObjectBuilder()
             .add("type", "home")
             .add("number", "212 555-1234"))
         .add(new JsonObjectBuilder()
             .add("type", "fax")
             .add("number", "646 555-4567")))
     .build();
 

JsonObject can be written to JSON as follows:

 JsonWriter writer = ...
 JsonObject obj = ...;
 writer.writeobject(obj);
 

JsonObject values can be JsonObject, JsonArray, JsonString, JsonNumber, JsonValue.TRUE, JsonValue.FALSE, JsonValue.NULL. These values can be accessed using various accessor methods.

In the above example 2, "John" can be got using

 String firstName = object.getStringValue("firstName");
 

This map object provides read-only access to the JSON object data, and attempts to modify the map, whether direct or via its collection views, result in an UnsupportedOperationException.

The map object's iteration ordering is based on the order in which name/value pairs are added to the corresponding builder or the order in which name/value pairs appear in the corresponding stream.

Author:

Jitendra Kotamraju

Nested Class Summary

Nested classes/interfaces inherited from interface javax.json.JsonValue

JsonValue.ValueType

Nested classes/interfaces inherited from interface java.util.Map

Map.Entry<K,V>

Field Summary

Fields inherited from interface javax.json.JsonValue

FALSE, NULL, TRUE

Method Summary

Methods

Modifier and Type	Method and Description
int	getIntValue(String name) A convenience method for getValue(name, JsonNumber.class).getIntValue()
String	getStringValue(String name) A convenience method for getValue(name, JsonString.class).getValue()
<T extends JsonValue> T	getValue(String name, Class<T> clazz) Returns the value to which the specified name is mapped.

Methods inherited from interface javax.json.JsonValue

getValueType, toString

Methods inherited from interface java.util.Map

clear, containsKey, containsValue, entrySet, equals, get, hashCode, isEmpty, keySet, put, putAll, remove, size, values

Method Detail

getValue

<T extends JsonValue> T getValue(String name,
                               Class<T> clazz)

Returns the value to which the specified name is mapped. This is just a convenience method for (T) get(name) to get the value.

Parameters:

name - the name(key) whose associated value is to be returned

clazz - value class

Returns:

the value to which the specified name is mapped, or null if this object contains no mapping for the name(key)

Throws:

ClassCastException - if the value for specified name/key mapping is not assignable to the type T

getStringValue

String getStringValue(String name)

A convenience method for getValue(name, JsonString.class).getValue()

Parameters:

name - whose associated value is to be returned as String

Returns:

the String value to which the specified name is mapped, null if this object contains no mapping for the name

Throws:

ClassCastException - if the value for specified name mapping is not assignable to JsonString

getIntValue

int getIntValue(String name)

A convenience method for getValue(name, JsonNumber.class).getIntValue()

Parameters:

name - whose associated value is to be returned as int

Returns:

the int value to which the specified name is mapped, null if this object contains no mapping for the name

Throws:

ClassCastException - if the value for specified name mapping is not assignable to JsonNumber