Question

我将我的Android应用程序中的参数发送到后端并尝试在我的POST方法中检索我的Android客户端发送的参数，但即使客户端发送的参数不是空，我也会继续获取空参数。

Java POST方法：

@POST
@Produces({ "application/json" })
@Path("/login")
public LoginResponse Login(@FormParam("email") String email, @FormParam("password") String password) {
    LoginResponse response = new LoginResponse();

    if(email != null && password != null && email.length() != 0 && password.length() != 0){
        //Detect if null or empty
        //Code
    }

    return response;
}

Android客户端：

HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://MY_APP_NAME.appspot.com/user/login");

String json = "";
JSONObject jsonObject = new JSONObject();

try {
    jsonObject.accumulate("email", "roger@gmail.com");
    jsonObject.accumulate("password", "123");

    json = jsonObject.toString();

    StringEntity se = new StringEntity(json);
    httppost.setEntity(se);
    httppost.setHeader("Content-Type", "application/json");
    httppost.setHeader("ACCEPT", "application/json");
    HttpResponse httpResponse = httpclient.execute(httppost);
}
catch(Exception ex) { }

我相信方法和客户端的Content-Type也是一样的。为什么我没有从Java后端方法接收参数？

选中：

网址正确且连接正常
应用发送的参数不为空

Answer 1

我们希望得到你，试试NameValuePair

public void postData() {
    HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost("http://www.yoursite.com/yourscript.php");

    try {

        List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
        nameValuePairs.add(new BasicNameValuePair("id", "123"));
        nameValuePairs.add(new BasicNameValuePair("string", "Hey"));
        httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

        // Execute HTTP Post Request
        HttpResponse response = httpclient.execute(httppost);

    } catch (ClientProtocolException e) {
        // Catch Protocol Exception
    } catch (IOException e) {
        // Catch IOException
    }
}

Answer 2

如果您遇到类似问题，我建议您使用Fiddler 这是一个免费的http检查器和调试器，通过它您可以看到您的应用程序发送到后端服务器的http请求和后端答案。

祝你好运

Java REST API：POST方法获取NULL参数

2 个答案: