com.github.fge.jsonpatch

Class JsonPatch

java.lang.Object

com.github.fge.jsonpatch.JsonPatch

public final class JsonPatch
extends Object

Implementation of JSON Patch

JSON Patch, as its name implies, is an IETF draft describing a mechanism to apply a patch to any JSON value. This implementation covers all operations according to the specification; however, there are some subtle differences with regards to some operations which are covered in these operations' respective documentation.

An example of a JSON Patch is as follows:

     [
         {
             "op": "add",
             "path": "/-",
             "value": {
                 "productId": 19,
                 "name": "Duvel",
                 "type": "beer"
             }
         }
     ]
 

This patch contains a single operation which adds an item at the end of an array. A JSON Patch can contain more than one operation; in this case, all operations are applied to the input JSON value in their order of appearance, until all operations are applied or an error condition is encountered.

The main point where this implementation differs from the specification is initial JSON parsing. The draft says:

     Operation objects MUST have exactly one "op" member
 

and:

     Additionally, operation objects MUST have exactly one "path" member.
 

However, obeying these to the letter forces constraints on the JSON parser. Here, these constraints are not enforced, which means:

     [ { "op": "add", "op": "remove", "path": "/x" } ]
 

is parsed (as a remove operation, since it appears last).

IMPORTANT NOTE: the JSON Patch is supposed to be VALID when the constructor for this class (fromJson(JsonNode) is used.

Method Summary

Methods

Modifier and Type	Method and Description
JsonNode	apply(JsonNode node) Apply this patch to a JSON value
static JsonPatch	fromJson(JsonNode node) Static factory method to build a JSON Patch out of a JSON representation
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

fromJson

public static JsonPatch fromJson(JsonNode node)
                          throws IOException

Static factory method to build a JSON Patch out of a JSON representation

Parameters:

node - the JSON representation of the generated JSON Patch

Returns:

a JSON Patch

Throws:

IOException - input is not a valid JSON patch

NullPointerException - input is null

apply

public JsonNode apply(JsonNode node)
               throws JsonPatchException

Apply this patch to a JSON value

Parameters:

node - the value to apply the patch to

Returns:

the patched JSON value

Throws:

JsonPatchException - failed to apply patch

NullPointerException - input is null

toString

public String toString()

Overrides:

toString in class Object