kafka Json 源码

kafka Json 代码

文件路径：/core/src/main/scala/kafka/utils/Json.scala

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package kafka.utils

import com.fasterxml.jackson.core.{JsonParseException, JsonProcessingException}
import com.fasterxml.jackson.databind.ObjectMapper
import com.fasterxml.jackson.databind.node.MissingNode
import kafka.utils.json.JsonValue

import scala.reflect.ClassTag

/**
 * Provides methods for parsing JSON with Jackson and encoding to JSON with a simple and naive custom implementation.
 */
object Json {

  private val mapper = new ObjectMapper()

  /**
   * Parse a JSON string into a JsonValue if possible. `None` is returned if `input` is not valid JSON.
   */
  def parseFull(input: String): Option[JsonValue] = tryParseFull(input).toOption

  /**
   * Parse a JSON string into either a generic type T, or a JsonProcessingException in the case of
   * exception.
   */
  def parseStringAs[T](input: String)(implicit tag: ClassTag[T]): Either[JsonProcessingException, T] = {
    try Right(mapper.readValue(input, tag.runtimeClass).asInstanceOf[T])
    catch { case e: JsonProcessingException => Left(e) }
  }

  /**
   * Parse a JSON byte array into a JsonValue if possible. `None` is returned if `input` is not valid JSON.
   */
  def parseBytes(input: Array[Byte]): Option[JsonValue] =
    try Option(mapper.readTree(input)).map(JsonValue(_))
    catch { case _: JsonProcessingException => None }

  def tryParseBytes(input: Array[Byte]): Either[JsonProcessingException, JsonValue] =
    try Right(mapper.readTree(input)).map(JsonValue(_))
    catch { case e: JsonProcessingException => Left(e) }

  /**
   * Parse a JSON byte array into either a generic type T, or a JsonProcessingException in the case of exception.
   */
  def parseBytesAs[T](input: Array[Byte])(implicit tag: ClassTag[T]): Either[JsonProcessingException, T] = {
    try Right(mapper.readValue(input, tag.runtimeClass).asInstanceOf[T])
    catch { case e: JsonProcessingException => Left(e) }
  }

  /**
   * Parse a JSON string into a JsonValue if possible. It returns an `Either` where `Left` will be an exception and
    * `Right` is the `JsonValue`.
   * @param input a JSON string to parse
   * @return An `Either` which in case of `Left` means an exception and `Right` is the actual return value.
   */
  def tryParseFull(input: String): Either[JsonProcessingException, JsonValue] =
    if (input == null || input.isEmpty)
      Left(new JsonParseException(MissingNode.getInstance().traverse(), "The input string shouldn't be empty"))
    else
      try Right(mapper.readTree(input)).map(JsonValue(_))
      catch { case e: JsonProcessingException => Left(e) }

  /**
   * Encode an object into a JSON string. This method accepts any type supported by Jackson's ObjectMapper in
   * the default configuration. That is, Java collections are supported, but Scala collections are not (to avoid
   * a jackson-scala dependency).
   */
  def encodeAsString(obj: Any): String = mapper.writeValueAsString(obj)

  /**
   * Encode an object into a JSON value in bytes. This method accepts any type supported by Jackson's ObjectMapper in
   * the default configuration. That is, Java collections are supported, but Scala collections are not (to avoid
   * a jackson-scala dependency).
   */
  def encodeAsBytes(obj: Any): Array[Byte] = mapper.writeValueAsBytes(obj)
}

相关信息

kafka 源码目录

相关文章

kafka Annotations 源码

kafka CommandDefaultOptions 源码

kafka CommandLineUtils 源码

kafka CoreUtils 源码

kafka DelayedItem 源码

kafka Exit 源码

kafka FileLock 源码

kafka Implicits 源码

kafka KafkaScheduler 源码

kafka Log4jController 源码