Package io.vertx.core.parsetools

## Interface JsonParser

- All Superinterfaces:
    `Handler<Buffer>`, `ReadStream<JsonEvent>`, `StreamBase`

      public interface JsonParser
      extends Handler<Buffer>, ReadStream<JsonEvent>

  A parser class which allows to incrementally parse json elements and emit json parse events instead of parsing a json element fully. This parser is convenient for parsing large json structures.

  The parser also parses concatenated json streams or line delimited json streams.

  The parser can also parse entire object or array when it is convenient, for instance a very large array of small objects can be parsed efficiently by handling array start/end and object events.

  Whenever the parser fails to parse or process the stream, the `exceptionHandler(Handler)` is called with the cause of the failure and the current handling stops. After such event, the parser should not handle data anymore.
  Author:
    Julien Viet

- - ### Method Summary

    All Methods Static Methods Instance Methods Abstract Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `JsonParser` | `arrayEventMode()` | Flip the parser to emit a stream of events for each new json array.
    `JsonParser` | `arrayValueMode()` | Flip the parser to emit a single value event for each new json array.
    `void` | `end()` | End the stream, this must be called after all the json stream has been processed.
    `JsonParser` | `endHandler​(Handler<Void> endHandler)` | Set an end handler.
    `JsonParser` | `exceptionHandler​(Handler<Throwable> handler)` | Set an exception handler on the read stream.
    `JsonParser` | `fetch​(long amount)` | Fetch the specified `amount` of elements.
    `JsonParser` | `handler​(Handler<JsonEvent> handler)` | Set a data handler.
    `static JsonParser` | `newParser()` | Create a new `JsonParser` instance.
    `static JsonParser` | `newParser​(ReadStream<Buffer> stream)` | Create a new `JsonParser` instance.
    `JsonParser` | `objectEventMode()` | Flip the parser to emit a stream of events for each new json object.
    `JsonParser` | `objectValueMode()` | Flip the parser to emit a single value event for each new json object.
    `JsonParser` | `pause()` | Pause the `ReadStream`, it sets the buffer in `fetch` mode and clears the actual demand.
    `JsonParser` | `resume()` | Resume reading, and sets the buffer in `flowing` mode.
    `JsonParser` | `write​(Buffer buffer)` | Handle a `Buffer`, pretty much like calling `Handler.handle(Object)`.

    - ### Methods inherited from interface io.vertx.core.Handler

      `handle`

    - ### Methods inherited from interface io.vertx.core.streams.ReadStream

      `collect, pipe, pipeTo`

- - ### Method Detail

    - #### newParser

          static JsonParser newParser()

      Create a new `JsonParser` instance.

    - #### newParser

          static JsonParser newParser​(ReadStream<Buffer> stream)

      Create a new `JsonParser` instance.

    - #### write

          JsonParser write​(Buffer buffer)

      Handle a `Buffer`, pretty much like calling `Handler.handle(Object)`.
      Returns:
        a reference to this, so the API can be used fluently

    - #### end

          void end()

      End the stream, this must be called after all the json stream has been processed.

    - #### objectEventMode

          JsonParser objectEventMode()

      Flip the parser to emit a stream of events for each new json object.
      Returns:
        a reference to this, so the API can be used fluently

    - #### objectValueMode

          JsonParser objectValueMode()

      Flip the parser to emit a single value event for each new json object. Json object currently streamed won't be affected.
      Returns:
        a reference to this, so the API can be used fluently

    - #### arrayEventMode

          JsonParser arrayEventMode()

      Flip the parser to emit a stream of events for each new json array.
      Returns:
        a reference to this, so the API can be used fluently

    - #### arrayValueMode

          JsonParser arrayValueMode()

      Flip the parser to emit a single value event for each new json array. Json array currently streamed won't be affected.
      Returns:
        a reference to this, so the API can be used fluently

    - #### pause

          JsonParser pause()

      Description copied from interface: `ReadStream`
      Pause the `ReadStream`, it sets the buffer in `fetch` mode and clears the actual demand.

      While it's paused, no data will be sent to the data `handler`.

      Specified by:
        `pause` in interface `ReadStream<JsonEvent>`
      Returns:
        a reference to this, so the API can be used fluently

    - #### resume

          JsonParser resume()

      Description copied from interface: `ReadStream`
      Resume reading, and sets the buffer in `flowing` mode.

      If the `ReadStream` has been paused, reading will recommence on it.
      Specified by:
        `resume` in interface `ReadStream<JsonEvent>`
      Returns:
        a reference to this, so the API can be used fluently

    - #### fetch

          JsonParser fetch​(long amount)

      Description copied from interface: `ReadStream`
      Fetch the specified `amount` of elements. If the `ReadStream` has been paused, reading will recommence with the specified `amount` of items, otherwise the specified `amount` will be added to the current stream demand.
      Specified by:
        `fetch` in interface `ReadStream<JsonEvent>`
      Returns:
        a reference to this, so the API can be used fluently

    - #### endHandler

          JsonParser endHandler​(Handler<Void> endHandler)

      Description copied from interface: `ReadStream`
      Set an end handler. Once the stream has ended, and there is no more data to be read, this handler will be called.
      Specified by:
        `endHandler` in interface `ReadStream<JsonEvent>`
      Returns:
        a reference to this, so the API can be used fluently

    - #### handler

          JsonParser handler​(Handler<JsonEvent> handler)

      Description copied from interface: `ReadStream`
      Set a data handler. As data is read, the handler will be called with the data.
      Specified by:
        `handler` in interface `ReadStream<JsonEvent>`
      Returns:
        a reference to this, so the API can be used fluently

    - #### exceptionHandler

          JsonParser exceptionHandler​(Handler<Throwable> handler)

      Description copied from interface: `ReadStream`
      Set an exception handler on the read stream.
      Specified by:
        `exceptionHandler` in interface `ReadStream<JsonEvent>`
      Specified by:
        `exceptionHandler` in interface `StreamBase`
      Parameters:
        `handler` - the exception handler
      Returns:
        a reference to this, so the API can be used fluently