大文件字符串读取

def readJsonFileToString(filePath: String):String = {
    val sb = new StringBuilder
    val buffer = new Array[Char](8192)
    val reader = new BufferedReader(new InputStreamReader(new FileInputStream(filePath), "UTF-8"))
    try {
      var n = 0
      while ({
        n = reader.read(buffer)
        n != -1
      }) {
        sb.appendAll(buffer, 0, n)
      }
    } finally {
      reader.close()
    }
    sb.toString()
  }

大文件写入

    val mapper = new ObjectMapper()
    val factory = new JsonFactory(mapper)
    val out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("/zzDatas/xxx4.json"), "UTF-8"))
    val jsonGenerator = factory.createGenerator(out)
    try {
      mapper.writeValue(jsonGenerator, gisMap)
    } finally {
      jsonGenerator.close()
      out.close()
    }