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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 {@link 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 {@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.
*
* The method {@link #getValue getValue()} returns the referenced value.
* Methods {@link #add add()}, {@link #replace replace()},
* and {@link #remove remove()} execute operations specified in
* RFC 6902.
*
* @see RFC 6901
* @see RFC 6902
*
* @since 1.1
*/
public interface JsonPointer {
/**
* Adds or replaces a value at the referenced location in the specified
* {@code target} with the specified {@code value}.
*
* - 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.
* - 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.
* - 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.
*
*
* @param 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 add(T target, JsonValue value);
/**
* Removes the value at the reference location in the specified {@code target}.
*
* @param 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 remove(T target);
/**
* Replaces the value at the referenced location in the specified
* {@code target} with the specified {@code value}.
*
* @param 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 replace(T target, JsonValue value);
/**
* 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 {@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);
}