{
  "added_at": "2026-11-09",
  "category": "reconstruction-cases",
  "class": "game",
  "description_en": "butterfly emulates the e-AMUSEMENT service used by DDR A so the game can connect to a local server. Its Java code handles profiles, scores, options and rivals, with support code for the service's packet encryption and compression.",
  "description_zh": "butterfly 模拟 DDR A 使用的 e-AMUSEMENT 服务，让游戏连接本地服务器。Java 代码处理玩家资料、成绩、选项和对手，并包含服务数据包加密与压缩的相关代码。",
  "entry_url": "https://awesomerea.org/resources/butterfly-ddr-a-service-case/",
  "entry_url_zh": "https://awesomerea.org/zh/resources/butterfly-ddr-a-service-case/",
  "evidence_url": "https://github.com/skogaby/butterfly/blob/469b79a9858f2153ab9e51b8b2754b2d3d8ff94e/README.md",
  "group": "cases",
  "id": "butterfly-ddr-a-service-case",
  "json_url": "https://awesomerea.org/resources/butterfly-ddr-a-service-case/record.json",
  "kind": "case-study",
  "markdown_url": "https://awesomerea.org/resources/butterfly-ddr-a-service-case/index.md",
  "markdown_url_zh": "https://awesomerea.org/zh/resources/butterfly-ddr-a-service-case/index.md",
  "name": "butterfly: emulating DDR A online services",
  "name_zh": "butterfly：模拟 DDR A 在线服务",
  "reconstruction_method": "other",
  "record_type": "resource",
  "relationship": "independent-reconstruction",
  "requirement_facets": [
    "prerequisites",
    "prerequisites",
    "limits",
    "license"
  ],
  "requirements": [
    "Java 11 or later on Windows, macOS or Linux.",
    "Set the game's services URL to http://localhost and turn off url_slash.",
    "Change options in the server's SQLite database; the server has no web UI. Event progress is not tracked.",
    "Licensed under Apache-2.0."
  ],
  "requirements_zh": [
    "在 Windows、macOS 或 Linux 上使用 Java 11 或更新版本。",
    "将游戏的 services URL 设为 http://localhost，并关闭 url_slash。",
    "需在服务器的 SQLite 数据库中修改选项；服务器没有网页界面。事件进度未被记录。",
    "采用 Apache-2.0 许可证。"
  ],
  "targets": [
    "game",
    "protocol"
  ],
  "url": "https://github.com/skogaby/butterfly",
  "verification": "source-reviewed",
  "verified_at": "2026-11-09"
}