Android HttpRequest崩溃

Question

我正在尝试在Android中创建一个登录系统。但每当我使用HttpRequest时，应用程序崩溃了。我使用Android Studio（0.8.9）和Sony Xperia L（4.2.2）作为测试设备。 我已经尝试了近30种不同的代码，但没有任何作用。 抱歉我的英语不好，我来自德国。 这是我的代码。

package de.bailey_rud.klasse10b;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
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.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import android.app.Activity;
import android.os.Bundle;
import android.os.StrictMode;
import android.util.Log;

public class FirstActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        if (android.os.Build.VERSION.SDK_INT > 9) {

            StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()

                    .permitAll().build();

            StrictMode.setThreadPolicy(policy);

        }

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_first);

        makePostRequest();

    }
    private void makePostRequest() {


        HttpClient httpClient = new DefaultHttpClient();
        // replace with your url
        HttpPost httpPost = new HttpPost("http://www.bailey-rud.de/api-login.php");


        //Post Data
        List<NameValuePair> nameValuePair = new ArrayList<NameValuePair>(2);
        nameValuePair.add(new BasicNameValuePair("username", "test_user"));
        nameValuePair.add(new BasicNameValuePair("password", "123456789"));


        //Encoding POST data
        try {
            httpPost.setEntity(new UrlEncodedFormEntity(nameValuePair));
        } catch (UnsupportedEncodingException e) {
            // log exception
            e.printStackTrace();
        }

        //making POST request.
        try {
            HttpResponse response = httpClient.execute(httpPost);
            // write response to log
            Log.d("Http Post Response:", response.toString());
        } catch (ClientProtocolException e) {
            // Log exception
            e.printStackTrace();
        } catch (IOException e) {
            // Log exception
            e.printStackTrace();
        }

    }

}