我正在尝试建立到APIendpoint的持久HTTP连接，该endpoint在新事件发生时发布分块JSON响应。我想提供一个回调，每次服务器发送新数据块时都会调用该回调，并无限期地保持连接打开。据我所知，HttpClient和HttpUrlConnection都不提供此功能。
有没有办法在不使用TCP套接字的情况下实现这一点？
一种解决方案是使用分隔符，例如\n\n来分隔每个json事件。您可以在发送之前从原始json中删除空行。调用setChankedStreamingMode（0）允许您在内容进来时读取内容（而不是在整个请求被缓冲之后）。然后您可以简单地遍历每一行，存储它们，直到到达空行，然后将存储的行解析为JSON。
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setChunkedStreamingMode(0);
conn.connect();
InputStream is = conn.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
StringBuffer sBuffer = new StringBuffer();
String line;
while ((line = reader.readLine()) != null) {
if (line.length() == 0) {
processJsonEvent(sBuffer.toString());
sBuffer.delete(0, sBuffer.length());
} else {
sBuffer.append(line);
sBuffer.append("\n");
}
}
据我所知，Android的HttpURLConnection不支持通过持久HTTP连接接收数据块；相反，它等待响应完全完成。
但是，使用HttpClient可以：
HttpClient httpClient = new DefaultHttpClient();
try {
HttpUriRequest request = new HttpGet(new URI("https://www.yourStreamingUrlHere.com"));
} catch (URISyntaxException e) {
e.printStackTrace();
}
try {
HttpResponse response = httpClient.execute(request);
InputStream responseStream = response.getEntity().getContent();
BufferedReader rd = new BufferedReader(new InputStreamReader(responseStream));
String line;
do {
line = rd.readLine();
// handle new line of data here
} while (!line.isEmpty());
// reaching here means the server closed the connection
} catch (Exception e) {
// connection attempt failed or connection timed out
}
