如何使用 Apache HTTPClient 4.5 发送带有 JSON 参数的 POST。获取 415 不支持的媒体类型

Question

我正在尝试向我的服务器（使用 Apache HTTPClient 4.5）发送一个 POST 请求，其中包含一组 JSON 参数。我已经关注了一些 SO 问题，但是 运行 遇到了问题。

当我使用 javascript 控制台发送请求时，它有效！像这样：

//Using JS console, I send a POST request and it works.
$.post('/createConfigData', {
    "tailSign": "A7ALE",
    "active": "Y"
});
//Get back 201

当我使用 Apache HTTPClient 4.5 尝试做与上面相同的事情时，我得到 415 unsupported media type:

HttpPost httppost = new HttpPost('/createConfigData');
String jsondata = "{\"tailSign\": \"A7ALE\",\"active\": \"Y\"}";

StringEntity jsonparam = new StringEntity(jsondata);
jsonparam.setContentType("application/json;charset=utf-8");
jsonparam.setChunked(true);

httppost.addHeader("content-type", "application/x-www-form-urlencoded;charset=UTF-8");
httppost.setEntity(jsonparam);

httpresponse = httpclient.execute(target, httppost);

我从 working 请求 得到的数据是：

• 请求Headers:
  • 主持人："mysite.com"
  • User-Agent: "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:25.0) Gecko/20100101 Firefox/25.0"
  • 接受："*/*"
  • Accept-Language: "en-US,en;q=0.5"
  • Accept-Encoding: "gzip, deflate"
  • Content-Type: "application/x-www-form-urlencoded; charset=UTF-8"
  • 推荐人："mysite.com/index.html"
  • Content-Length: "288"
  • Cookie："JSESSIONID=..."
  • Proxy-Authorization: "Basic ..."
  • 连接："keep-alive"
  • 编译指示："no-cache"
  • Cache-Control: "no-cache"
• 回复Headers:
  • 年龄：“0”
  • 连接："Keep-Alive"
  • Content-Type: "application/json;charset=UTF-8"
  • 日期："Wed, 19 Oct 2016 17:57:34 GMT"
  • 服务器："Apache-Coyote/1.1"
  • Transfer-Encoding: "chunked"

我对在哪里设置内容类型有点困惑，无论是 entity 还是 httppost

=======================

更多测试用例

将 httppost 的 内容类型设置为 json 给我 400

HttpPost httppost = new HttpPost('/createConfigData');
String jsondata = "{\"tailSign\": \"A7ALE\",\"active\": \"Y\"}";

StringEntity jsonparam = new StringEntity(jsondata);
jsonparam.setChunked(true);

httppost.addHeader("content-type", "application/json;charset=UTF-8");
httppost.setEntity(jsonparam);

httpresponse = httpclient.execute(target, httppost);

---

将 httppost 的 内容类型设置为 x-www-form-urlencoded 给我 415

HttpPost httppost = new HttpPost('/createConfigData');
String jsondata = "{\"tailSign\": \"A7ALE\",\"active\": \"Y\"}";

StringEntity jsonparam = new StringEntity(jsondata);
jsonparam.setChunked(true);

httppost.addHeader("content-type", "application/x-www-form-urlencoded;charset=UTF-8");
httppost.setEntity(jsonparam);

httpresponse = httpclient.execute(target, httppost);

---

我也试过添加这一行：

httppost.addHeader("Accept", "*/*");

---

==================

解决方案

使用 wireshark 我发现有一条错误消息伴随着 400 错误请求！只是我的 JSON 不正确。

HTTP/1.1 400 Bad Request
Server: Apache-Coyote/1.1
Content-Type: application/json;charset=UTF-8
Transfer-Encoding: chunked
Date: Wed, 19 Oct 2016 21:33:25 GMT
Proxy-Connection: Keep-Alive
Connection: Keep-Alive

{"code":400,"message":"Field ConfigName is Null, Invalid Value for Seat Count, Missing counts for DSU, ICMT, SVDU, TPMU, Login user details not found, Please enter valid lruData","fleetData":{"airlineData":null,"dimAircraftJson":null,"configData":null}}

Answer 1

您得到 415 不受支持的媒体类型 因为您已经将 content-type header 覆盖为 application/x-www-form-urlencoded;字符集=UTF-8。只需将其更改为：

HttpPost httppost = new HttpPost('/createConfigData');
String jsondata = "{\"tailSign\": \"A7ALE\",\"active\": \"Y\"}";
StringEntity jsonparam = new StringEntity(jsondata);
jsonparam.setChunked(true);

httppost.addHeader("content-type", "application/json;charset=UTF-8");
httppost.setEntity(jsonparam);

httpresponse = httpclient.execute(target, httppost);