@bigcyy
研究出来了，贴这里供大家参考，我这里是mirai最新的稳定版
//判断其是否是文件信息
boolean isFileMsg = message.stream().anyMatch((singleMessage) -> singleMessage instanceof FileMessage);
if (isFileMsg) { //如果是文件
Optional<SingleMessage> first = message.stream().filter((singleMessage) -> singleMessage instanceof FileMessage).findFirst();
SingleMessage singleMessage;
if(first.isPresent()) {
singleMessage = first.get();
AbsoluteFile absoluteFile = ((FileMessage) singleMessage).toAbsoluteFile(group); //从刚刚发送文件的的群里获取该文件
String fileName = absoluteFile.getName();
String url = absoluteFile.getUrl(); //得到url
OkHttpClient okHttpClient = new OkHttpClient(); //用okhttp发送请求，转成流
Request request = new Request.Builder().url(url).build();
okHttpClient.newCall(request).enqueue(new Callback() {
@Override
public void onFailure(@NotNull Call call, @NotNull IOException e) {
e.printStackTrace();
}
@Override
public void onResponse(@NotNull Call call, @NotNull Response response) throws IOException {
try {
InputStream inputStream = response.body().byteStream(); //转成流
ExternalResource res = ExternalResource.create(inputStream).toAutoCloseable(); //用mirai的ExternalResource包装
pushGroup.getFiles().uploadNewFile("/" + fileName, res);
inputStream.close();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
}
