/**
* Method for locating node specified by given JSON pointer instances. Method will never return
* null; if no matching node exists, will return a node for which {@link #isMissingNode()} returns
* true.
*
* @return Node that matches given JSON Pointer: if no match exists, will return a node for which
* {@link #isMissingNode()} returns true.
* @since 2.3
*/
@Override
public final JsonNode at(JsonPointer ptr) {
// Basically: value nodes only match if we have "empty" path left
if (ptr.matches()) {
return this;
}
JsonNode n = _at(ptr);
if (n == null) {
return MissingNode.getInstance();
}
return n.at(ptr.tail());
}
/**
* Convenience method that is functionally equivalent to:
*
* <pre>
* return at(JsonPointer.valueOf(jsonPointerExpression));
* </pre>
*
* <p>Note that if the same expression is used often, it is preferable to construct {@link
* JsonPointer} instance once and reuse it: this method will not perform any caching of compiled
* expressions.
*
* @param jsonPtrExpr Expression to compile as a {@link JsonPointer} instance
* @return Node that matches given JSON Pointer: if no match exists, will return a node for which
* {@link TreeNode#isMissingNode()} returns true.
* @since 2.3
*/
@Override
public final JsonNode at(String jsonPtrExpr) {
return at(JsonPointer.compile(jsonPtrExpr));
}