听马伟奇的《十分钟完成开源中国》仿写，写登陆模块时访问https://www.oschina.net/action/api/login_validate
提交参数"keep_login","username","pwd"无响应，不能返回登陆结果字符串，请问这是怎么回事？
public class LoginActivity extends AppCompatActivity {
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
Request request = ItheimaHttp.newGetRequest("action/api/login_validate");
request.putParams("keep_login",1)
.putParams("username","xx@qq.com")
.putParams("pwd","xx");
Call call = ItheimaHttp.send(request, new HttpResponseListener<String>() {
@Override
public void onResponse(String s, Headers headers) {
System.out.println(s);
}
});
}
}
响应函数是运行了的，但是字符串里面是空的，日志也没有报错。