jakarta.json.JsonObject Maven / Gradle / Ivy
/*
* Copyright (c) 2011, 2020 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package jakarta.json;
import java.util.Map;
/**
* {@code 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
* {@link JsonReader#readObject()}. For example:
*
* JsonReader jsonReader = Json.createReader(...);
* JsonObject object = jsonReader.readObject();
* jsonReader.close();
*
*
* It can also be built from scratch using a {@link JsonObjectBuilder}.
*
* For example 1: An empty JSON object can be built as follows:
*
* JsonObject object = Json.createObjectBuilder().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 = Json.createObjectBuilder()
* .add("firstName", "John")
* .add("lastName", "Smith")
* .add("age", 25)
* .add("address", Json.createObjectBuilder()
* .add("streetAddress", "21 2nd Street")
* .add("city", "New York")
* .add("state", "NY")
* .add("postalCode", "10021"))
* .add("phoneNumber", Json.createArrayBuilder()
* .add(Json.createObjectBuilder()
* .add("type", "home")
* .add("number", "212 555-1234"))
* .add(Json.createObjectBuilder()
* .add("type", "fax")
* .add("number", "646 555-4567")))
* .build();
*
*
* {@code JsonObject} can be written to JSON as follows:
*
* JsonWriter writer = ...
* JsonObject obj = ...;
* writer.writeObject(obj);
*
*
* {@code JsonObject} values can be {@link JsonObject}, {@link JsonArray},
* {@link JsonString}, {@link JsonNumber}, {@link JsonValue#TRUE},
* {@link JsonValue#FALSE}, {@link JsonValue#NULL}. These values can be
* accessed using various accessor methods.
*
* In the above example 2, "John" can be got using
*
* String firstName = object.getString("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 {@code 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.
*/
public interface JsonObject extends JsonStructure, Map {
/**
* Returns the array value to which the specified name is mapped.
* This is a convenience method for {@code (JsonArray)get(name)} to
* get the value.
*
* @param name the name whose associated value is to be returned
* @return the array value to which the specified name is mapped, or
* {@code null} if this object contains no mapping for the name
* @throws ClassCastException if the value to which the specified name
* is mapped is not assignable to JsonArray type
*/
JsonArray getJsonArray(String name);
/**
* Returns the object value to which the specified name is mapped.
* This is a convenience method for {@code (JsonObject)get(name)} to
* get the value.
*
* @param name the name whose associated value is to be returned
* @return the object value to which the specified name is mapped, or
* {@code null} if this object contains no mapping for the name
* @throws ClassCastException if the value to which the specified name
* is mapped is not assignable to JsonObject type
*/
JsonObject getJsonObject(String name);
/**
* Returns the number value to which the specified name is mapped.
* This is a convenience method for {@code (JsonNumber)get(name)} to
* get the value.
*
* @param name the name whose associated value is to be returned
* @return the number value to which the specified name is mapped, or
* {@code null} if this object contains no mapping for the name
* @throws ClassCastException if the value to which the specified name
* is mapped is not assignable to JsonNumber type
*/
JsonNumber getJsonNumber(String name);
/**
* Returns the string value to which the specified name is mapped.
* This is a convenience method for {@code (JsonString)get(name)} to
* get the value.
*
* @param name the name whose associated value is to be returned
* @return the string value to which the specified name is mapped, or
* {@code null} if this object contains no mapping for the name
* @throws ClassCastException if the value to which the specified name
* is mapped is not assignable to JsonString type
*/
JsonString getJsonString(String name);
/**
* A convenience method for
* {@code getJsonString(name).getString()}
*
* @param name whose associated value is to be returned as String
* @return the String value to which the specified name is mapped
* @throws NullPointerException if the specified name doesn't have any
* mapping
* @throws ClassCastException if the value for specified name mapping
* is not assignable to JsonString
*/
String getString(String name);
/**
* Returns the string value of the associated {@code JsonString} mapping
* for the specified name. If {@code JsonString} is found, then its
* {@link jakarta.json.JsonString#getString()} is returned. Otherwise,
* the specified default value is returned.
*
* @param name whose associated value is to be returned as String
* @param defaultValue a default value to be returned
* @return the string value of the associated mapping for the name,
* or the default value
*/
String getString(String name, String defaultValue);
/**
* A convenience method for
* {@code getJsonNumber(name).intValue()}
*
* @param name whose associated value is to be returned as int
* @return the int value to which the specified name is mapped
* @throws NullPointerException if the specified name doesn't have any
* mapping
* @throws ClassCastException if the value for specified name mapping
* is not assignable to JsonNumber
*/
int getInt(String name);
/**
* Returns the int value of the associated {@code JsonNumber} mapping
* for the specified name. If {@code JsonNumber} is found, then its
* {@link jakarta.json.JsonNumber#intValue()} is returned. Otherwise,
* the specified default value is returned.
*
* @param name whose associated value is to be returned as int
* @param defaultValue a default value to be returned
* @return the int value of the associated mapping for the name,
* or the default value
*/
int getInt(String name, int defaultValue);
/**
* Returns the boolean value of the associated mapping for the specified
* name. If the associated mapping is JsonValue.TRUE, then returns true.
* If the associated mapping is JsonValue.FALSE, then returns false.
*
* @param name whose associated value is to be returned as boolean
* @return the boolean value to which the specified name is mapped
* @throws NullPointerException if the specified name doesn't have any
* mapping
* @throws ClassCastException if the value for specified name mapping
* is not assignable to JsonValue.TRUE or JsonValue.FALSE
*/
boolean getBoolean(String name);
/**
* Returns the boolean value of the associated mapping for the specified
* name. If the associated mapping is JsonValue.TRUE, then returns true.
* If the associated mapping is JsonValue.FALSE, then returns false.
* Otherwise, the specified default value is returned.
*
* @param name whose associated value is to be returned as int
* @param defaultValue a default value to be returned
* @return the boolean value of the associated mapping for the name,
* or the default value
*/
boolean getBoolean(String name, boolean defaultValue);
/**
* Returns {@code true} if the associated value for the specified name is
* {@code JsonValue.NULL}.
*
* @param name name whose associated value is checked
* @return return true if the associated value is {@code JsonValue.NULL},
* otherwise false
* @throws NullPointerException if the specified name doesn't have any
* mapping
*/
boolean isNull(String name);
}