如何将带有参数的https发送请求发送至api

Question

我正在尝试向发送json响应的api发送https post请求，这是一个搜索功能，因此需要1个参数，但是我无法从api中获得预期的结果，这是我的代码

Handler.java

import android.util.Log;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.scheme.Scheme;
import org.apache.http.conn.scheme.SchemeRegistry;
import org.apache.http.conn.ssl.SSLSocketFactory;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.impl.conn.SingleClientConnManager;
import org.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpParams;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.util.List;

import javax.net.ssl.HttpsURLConnection;

public class Handler {
    static InputStream is = null;
    static String response = null;
    public final static int GET = 1;
    public final static int POST = 2;

    public Handler(){

    }
    public String makeServiceCall(String url, int method) {
        return this.makeServiceCall(url, method, null);
    }

    public String makeServiceCall(String url, int method, List<NameValuePair> params){
        try {

            SchemeRegistry schemeRegistry = new SchemeRegistry();
            schemeRegistry.register(new Scheme("https", SSLSocketFactory.getSocketFactory(), 443));
            HttpParams params2 = new BasicHttpParams();
            SingleClientConnManager mgr = new SingleClientConnManager(params2, schemeRegistry);
            DefaultHttpClient httpClient = new DefaultHttpClient(mgr, params2);
            HttpEntity httpEntity = null;
            HttpResponse httpResponse = null;

            if(method == POST){
                HttpPost httpPost = new HttpPost(url);
                if(params != null){
                    httpPost.setEntity(new UrlEncodedFormEntity(params));
                }
                httpResponse = httpClient.execute(httpPost);
            } else if (method == GET) {
                HttpGet httpGet = new HttpGet(url);
                httpResponse = httpClient.execute(httpGet);
            }
            httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e){
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(is, "UTF-8"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while((line = reader.readLine()) != null){
                sb.append(line + "\n");
            }
            is.close();
            response = sb.toString();
        } catch (Exception e){
            Log.e("Buffer Error", "Error : " + e.toString());
        }
        return response;
    }

makeServiceCall用于向url发出请求，但仅适用于GET请求，而不能用于POST请求，我该如何解决？