我有一个resteasy客户端，它使用InvocationCallback进行异步调用，该调用将响应返回到completed（）方法中。
当我在debug或do中查看响应对象时
response.getHeaders()
我只有两个
Content-Type:application/json
Server:Jetty(6.1.26)
在调试模式下，当我查看日志时会得到
2018-08-10 11:48:46,603 DEBUG (21321) %T pool-6-thread-1 [apache.http.headers] http-outgoing-0 << HTTP/1.1 200 OK
2018-08-10 11:48:46,603 DEBUG (21321) %T pool-6-thread-1 [apache.http.headers] http-outgoing-0 << Content-Type: application/json
2018-08-10 11:48:46,603 DEBUG (21321) %T pool-6-thread-1 [apache.http.headers] http-outgoing-0 << Content-Encoding: gzip
2018-08-10 11:48:46,603 DEBUG (21321) %T pool-6-thread-1 [apache.http.headers] http-outgoing-0 << Content-Length: 459
2018-08-10 11:48:46,603 DEBUG (21321) %T pool-6-thread-1 [apache.http.headers] http-outgoing-0 << Server: Jetty(6.1.26)
所以他们在那里。为什么在getHeader（）中未返回“ Content-Length：459”和“ Content-Encoding：gzip”。 response.getLength（）返回-1;实际上，getLength表示它提供了Content-Length的值。
public void completed(Response response) {
log.info("Response Completed with response: " + response.getStatus());
response.getHeaders();// returns only 2 in multiValuemap
response.getLength(); // returns -1
}