https://github.com/eclipse-ee4j/jsonp: Jakarta JSON Processing defines a Java(R) based framework for parsing, generating, transforming, and querying JSON documents. (Eclipse Foundation)
  • Dmitry Kornilov (Oracle)
  • Lukas Jungmann (Oracle) 
/*
 * Copyright (c) 2015, 2017 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 javax.json;


This interface represents an immutable implementation of a JSON Pointer
as defined by RFC 6901.



 A JSON Pointer, when applied to a target JsonValue, defines a reference location in the target.


 An empty JSON Pointer string defines a reference to the target itself.


 If the JSON Pointer string is non-empty, it must be a sequence of '/' prefixed tokens, and the target must either be a JsonArray or JsonObject. If the target is a JsonArray, the pointer defines a reference to an array element, and the last token specifies the index. If the target is a JsonObject, the pointer defines a reference to a name/value pair, and the last token specifies the name. 


 The method getValue() returns the referenced value. Methods add(), replace(), and remove() execute operations specified in RFC 6902. 


See Also:
Since:1.1
/**
 * <p>This interface represents an immutable implementation of a JSON Pointer
 * as defined by <a href="http://tools.ietf.org/html/rfc6901">RFC 6901</a>.
 * </p>
 * <p> A JSON Pointer, when applied to a target {@link JsonValue},
 * defines a reference location in the target.</p>
 * <p> An empty JSON Pointer string defines a reference to the target itself.</p>
 * <p> If the JSON Pointer string is non-empty, it must be a sequence
 * of '/' prefixed tokens, and the target must either be a {@link JsonArray}
 * or {@link JsonObject}. If the target is a {@code JsonArray}, the pointer
 * defines a reference to an array element, and the last token specifies the index.
 * If the target is a {@link JsonObject}, the pointer defines a reference to a
 * name/value pair, and the last token specifies the name.
 * </p>
 * <p> The method {@link #getValue getValue()} returns the referenced value.
 * Methods {@link #add add()}, {@link #replace replace()},
 * and {@link #remove remove()} execute operations specified in
 * <a href="http://tools.ietf.org/html/rfc6902">RFC 6902</a>. </p>
 *
 * @see <a href="http://tools.ietf.org/html/rfc6901">RFC 6901</a>
 * @see <a href="http://tools.ietf.org/html/rfc6902">RFC 6902</a>
 *
 * @since 1.1
 */
public interface JsonPointer {

    
Adds or replaces a value at the referenced location in the specified target with the specified value. 
    

  1. If the reference is the target (empty JSON Pointer string), the specified value, which must be the same type as specified target, is returned.
    2. 

  2. If the reference is an array element, the specified value is inserted into the array, at the referenced index. The value currently at that location, and any subsequent values, are shifted to the right (adds one to the indices). Index starts with 0. If the reference is specified with a "-", or if the index is equal to the size of the array, the value is appended to the array.
    3. 

  3. If the reference is a name/value pair of a JsonObject, and the referenced value exists, the value is replaced by the specified value. If the value does not exist, a new name/value pair is added to the object.
    4. 



Params:
  • target – the target referenced by this JsonPointer
  • value – the value to be added
Type parameters:
  • <T> – the target type, must be a subtype of JsonValue
Throws:
  • NullPointerException – if target is null
  • JsonException – if the reference is an array element and the index is out of range (index < 0 || index > array size), or if the pointer contains references to non-existing objects or arrays.
Returns:the transformed target after the value is added.
/**
     * Adds or replaces a value at the referenced location in the specified
     * {@code target} with the specified {@code value}.
     * <ol>
     * <li>If the reference is the target (empty JSON Pointer string),
     * the specified {@code value}, which must be the same type as
     * specified {@code target}, is returned.</li>
     * <li>If the reference is an array element, the specified {@code value} is inserted
     * into the array, at the referenced index. The value currently at that location, and
     * any subsequent values, are shifted to the right (adds one to the indices).
     * Index starts with 0. If the reference is specified with a "-", or if the
     * index is equal to the size of the array, the value is appended to the array.</li>
     * <li>If the reference is a name/value pair of a {@code JsonObject}, and the
     * referenced value exists, the value is replaced by the specified {@code value}.
     * If the value does not exist, a new name/value pair is added to the object.</li>
     * </ol>
     *
     * @param <T> the target type, must be a subtype of {@link JsonValue}
     * @param target the target referenced by this {@code JsonPointer}
     * @param value the value to be added
     * @return the transformed {@code target} after the value is added.
     * @throws NullPointerException if {@code target} is {@code null}
     * @throws JsonException if the reference is an array element and
     * the index is out of range ({@code index < 0 || index > array size}),
     * or if the pointer contains references to non-existing objects or arrays.
     */
    <T extends JsonStructure> T add(T target, JsonValue value);

    
Removes the value at the reference location in the specified target. 
Params:
  • target – the target referenced by this JsonPointer
Type parameters:
  • <T> – the target type, must be a subtype of JsonValue
Throws:
Returns:the transformed target after the value is removed.
/**
     * Removes the value at the reference location in the specified {@code target}.
     *
     * @param <T> the target type, must be a subtype of {@link JsonValue}
     * @param target the target referenced by this {@code JsonPointer}
     * @return the transformed {@code target} after the value is removed.
     * @throws NullPointerException if {@code target} is {@code null}
     * @throws JsonException if the referenced value does not exist,
     *    or if the reference is the target.
     */
    <T extends JsonStructure> T remove(T target);

    
Replaces the value at the referenced location in the specified target with the specified value. 
Params:
  • target – the target referenced by this JsonPointer
  • value – the value to be stored at the referenced location
Type parameters:
  • <T> – the target type, must be a subtype of JsonValue
Throws:
Returns:the transformed target after the value is replaced.
/**
     * Replaces the value at the referenced location in the specified
     * {@code target} with the specified {@code value}.
     *
     * @param <T> the target type, must be a subtype of {@link JsonValue}
     * @param target the target referenced by this {@code JsonPointer}
     * @param value the value to be stored at the referenced location
     * @return the transformed {@code target} after the value is replaced.
     * @throws NullPointerException if {@code target} is {@code null}
     * @throws JsonException if the referenced value does not exist,
     *    or if the reference is the target.
     */
    <T extends JsonStructure> T replace(T target, JsonValue value);

    
Returns true if there is a value at the referenced location in the specified target. 
Params:
  • target – the target referenced by this JsonPointer
Returns:true if this pointer points to a value in a specified target.
/**
     * Returns {@code true} if there is a value at the referenced location in the specified {@code target}.
     *
     * @param target the target referenced by this {@code JsonPointer}
     * @return {@code true} if this pointer points to a value in a specified {@code target}.
     */
    boolean containsValue(JsonStructure target);

    
Returns the value at the referenced location in the specified target. 
Params:
  • target – the target referenced by this JsonPointer
Throws:
Returns:the referenced value in the target.
/**
     * Returns the value at the referenced location in the specified {@code target}.
     *
     * @param target the target referenced by this {@code JsonPointer}
     * @return the referenced value in the target.
     * @throws NullPointerException if {@code target} is null
     * @throws JsonException if the referenced value does not exist
     */
    JsonValue getValue(JsonStructure target);
}