发送POST请求时无法获取POST参数，请使用Retrofit

Question

我正在使用Retrofit 2.0.0将POST请求发送到我的REST API。

private class AuthTask extends AsyncTask<String, String, String> { 
    protected String doInBackground(String... params) { 
     Call<Auth> call = service.auth(params[0], params[1]); 
     try { 
      Auth authResponse = call.execute().body(); 
      Log.i(AuthActivity.class.getName(), authResponse.public_key); 
     } catch (IOException ex) { 
      Log.e(AuthActivity.class.getName(), "Error."); 
      return "error"; 
     } 
     return "success"; 
    } 

    protected void onPostExecute(String result) { 
     Log.i(AuthTask.class.getName(), "Done"); 
    } 
} 

---

public class Auth { 
    public String public_key; 
} 

---

public interface AuthService { 
    @FormUrlEncoded 
    @POST("auth") 
    Call<Auth> auth(@Field("username") String username, @Field("publickey") String publickey); 
} 

这里是我的请求日志输出：

12-14 19:36:54.014 30318-30373/com.app D/OkHttp: --> POST /auth HTTP/1.1 
12-14 19:36:54.014 30318-30373/com.app D/OkHttp: username=ghtbznz&publickey=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCedhOhP9MgYufDxPKH1DdtJiBBdBtbsUy8R7kg%0AWm1Edm7c3ThToMxMgjvOAsHn8rP1Ka1eVN34hC4HV2%2BoomRaWH25WbunN9ZVRqBnowsTOd40eEKh%0A6dsO8Cl3u65VsArDyZyEQa7Ofx29i2juOpWRG%2F6tp9FVnJzZt5dBDkWOKwIDAQAB%0A 
12-14 19:36:54.014 30318-30373/com.app D/OkHttp: --> END POST (256-byte body) 

这里是为响应日志输出：

12-14 19:42:20.358 2549-2804/com.app D/OkHttp: <-- HTTP/1.1 200 OK (1790ms) 
12-14 19:42:20.358 2549-2804/com.app D/OkHttp: Date: Mon, 14 Dec 2015 18:42:16 GMT 
12-14 19:42:20.358 2549-2804/com.app D/OkHttp: Server: Apache/2.2.22 (Debian) 
12-14 19:42:20.358 2549-2804/com.app D/OkHttp: Vary: Accept-Encoding 
12-14 19:42:20.358 2549-2804/com.app D/OkHttp: Keep-Alive: timeout=5, max=99 
12-14 19:42:20.366 2549-2804/com.app D/OkHttp: Connection: Keep-Alive 
12-14 19:42:20.366 2549-2804/com.app D/OkHttp: Content-Type: text/html 
12-14 19:42:20.366 2549-2804/com.app D/OkHttp: OkHttp-Selected-Protocol: http/1.1 
12-14 19:42:20.366 2549-2804/com.app D/OkHttp: OkHttp-Sent-Millis: 1450118540088 
12-14 19:42:20.366 2549-2804/com.app D/OkHttp: OkHttp-Received-Millis: 1450118540358 
12-14 19:42:20.373 2549-2804/com.app D/OkHttp: 
12-14 19:42:20.373 2549-2804/com.app D/OkHttp: 
12-14 19:42:20.373 2549-2804/com.app D/OkHttp: 
12-14 19:42:20.373 2549-2804/com.app D/OkHttp: array(0) { 
12-14 19:42:20.373 2549-2804/com.app D/OkHttp: } 
12-14 19:42:20.373 2549-2804/com.app D/OkHttp: Notice: Undefined index: username in /home/auth/index.php on line 45 
12-14 19:42:20.373 2549-2804/com.app D/OkHttp: Notice: Undefined index: publickey in /home/auth/index.php on line 46 
12-14 19:42:20.373 2549-2804/com.app D/OkHttp: <-- END HTTP (251-byte body) 

在我的PHP文件，这是我找回POST参数：

$user = $_POST["username"]; 
$pk = $_POST["publickey"]; 

奇怪的是，当我使用curl发送POST请求一切正常。所以我的问题是为什么我无法使用Retrofit发送正确的POST参数？

Answer 1

我在我的Android手机上安装了应用程序鲨鱼，并嗅探了流量。最后，我发现发生了重定向（301），因此所有POST参数都消失了。

解决方案非常简单。只需在REST端点之后添加斜线即可：

public interface AuthService { 
    @FormUrlEncoded 
    @POST("auth/") 
    Call<Auth> auth(@Field("username") String username, @Field("publickey") String publickey); 
} 

Answer 2

改装可能类似于Angular，因为数据作为MIME类型“application/json”而不是“application/x-www-form-urlencoded”或“multipart/form-data”发布。如果它是“application/json”，PHP将不会将数据解析到$ _POST中。所以，你必须做你自己。我做这样的事情...

if (isset($_SERVER['CONTENT_TYPE']) 
    and stripos($_SERVER['CONTENT_TYPE'], 'application/json') !== false 
) { 
    $jsonEncoded = file_get_contents('php://input'); 
    $jsonDecoded = json_decode($jsonEncoded, true); 
    if (is_array($jsonDecoded)) { 
     foreach ($jsonDecoded as $varName => $varValue) { 
      $_POST[$varName] = $varValue; 
     } 
    } 
}