我正在尝试在我的android应用程序中使用php、json和mysql制作一个身份验证系统，但是我一直在尝试 connection to url refused .
这是我第一次使用这种方法，它是基于一个教程，当然我会感谢任何其他的建议
这是我用java编写的register活动类：

public class RegisterActivity extends Activity {

private Button btn_register;
private TextView btn_login;

private EditText et_login;
private EditText et_pass, et_confirm_pass;

JSONParser jsonParser = new JSONParser();

// url to create new product
private static String url_create_user = "http://172.16.21.5/ladies_api/register.php";

// JSON Node names
private static final String TAG_SUCCESS = "success";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_register);

    btn_login = (TextView) findViewById(R.id.tv_login);
    btn_register = (Button) findViewById(R.id.btn_reg);

    et_login = (EditText) findViewById(R.id.et_username);
    et_pass = (EditText) findViewById(R.id.et_password);
    et_confirm_pass = (EditText) findViewById(R.id.et_c_password);

    btn_register.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            String login = et_login.getText().toString();
            String pwd = et_pass.getText().toString();
            String c_pwd = et_confirm_pass.getText().toString();
            /**REGISTER USER, GO TO HOME */
            //new CreateNewUser().execute();
            AsyncDataClass asyncRequestObject = new AsyncDataClass();

            asyncRequestObject.execute(url_create_user, login, pwd);
        }
    });

    btn_login.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent = new Intent(RegisterActivity.this, LoginActivity.class);
            startActivity(intent);
        }
    });
}

private class AsyncDataClass extends AsyncTask<String, Void, String>{

    @Override
    protected String doInBackground(String... params) {
        HttpParams httpParameters = new BasicHttpParams();

        HttpConnectionParams.setConnectionTimeout(httpParameters, 5000);

        HttpConnectionParams.setSoTimeout(httpParameters, 5000);

        HttpClient httpClient = new DefaultHttpClient(httpParameters);

        HttpPost httpPost = new HttpPost(params[0]);

        String jsonResult = "";

        try {

            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);

            nameValuePairs.add(new BasicNameValuePair("username", params[1]));

            nameValuePairs.add(new BasicNameValuePair("pwd", params[2]));

            httpPost.setEntity(new UrlEncodedFormEntity(nameValuePairs));

            HttpResponse response = httpClient.execute(httpPost);

            jsonResult = inputStreamToString(response.getEntity().getContent()).toString();

            System.out.println("Returned Json object " + jsonResult.toString());

        } catch (ClientProtocolException e) {

            e.printStackTrace();

        } catch (IOException e) {

            e.printStackTrace();

        }

        return jsonResult;
    }
    @Override

    protected void onPreExecute() {

        super.onPreExecute();

    }

    @Override

    protected void onPostExecute(String result) {

        super.onPostExecute(result);

        System.out.println("Resulted Value: " + result);

        if(result.equals("") || result == null){

            Toast.makeText(RegisterActivity.this, "Server connection failed", Toast.LENGTH_LONG).show();

            return;

        }

        int jsonResult = returnParsedJsonObject(result);

        if(jsonResult == 0){

            Toast.makeText(RegisterActivity.this, "Invalid username or password or email", Toast.LENGTH_LONG).show();

            return;

        }

        if(jsonResult == 1){

            Intent intent = new Intent(RegisterActivity.this, MainActivity.class);

            startActivity(intent);

        }

    }

private StringBuilder inputStreamToString(InputStream is) {

    String rLine = "";

    StringBuilder answer = new StringBuilder();

    BufferedReader br = new BufferedReader(new InputStreamReader(is));

    try {

        while ((rLine = br.readLine()) != null) {

            answer.append(rLine);

        }

    } catch (IOException e) {

        e.printStackTrace();

    }

    return answer;

}
private int returnParsedJsonObject(String result){

        JSONObject resultObject = null;

        int returnedResult = 0;

        try {

            resultObject = new JSONObject(result);

            returnedResult = resultObject.getInt("success");

        } catch (JSONException e) {

            e.printStackTrace();

        }

        return returnedResult;

    }
}
}

这是jasonparser类

public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";

// constructor
public JSONParser() {

}

// function get json from url
// by making HTTP POST or GET method
public JSONObject makeHttpRequest(String url, String method,
                                  List<NameValuePair> params) {

    // Making HTTP request
    try {

        // check for request method
        if(method == "POST"){
            // request method is POST
            // defaultHttpClient
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);
            httpPost.setEntity(new UrlEncodedFormEntity(params));

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();

        }else if(method == "GET"){
            // request method is GET
            DefaultHttpClient httpClient = new DefaultHttpClient();
            String paramString = URLEncodedUtils.format(params, "utf-8");
            url += "?" + paramString;
            HttpGet httpGet = new HttpGet(url);

            HttpResponse httpResponse = httpClient.execute(httpGet);
            HttpEntity 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, "iso-8859-1"), 8);
        StringBuilder sb = new StringBuilder();
        String line = null;
        while ((line = reader.readLine()) != null) {
            sb.append(line + "\n");
        }
        is.close();
        json = sb.toString();
    } catch (Exception e) {
    }

    // try parse the string to a JSON object
    try {
        jObj = new JSONObject(json);
    } catch (JSONException e) {

    }

    // return JSON String
    return jObj;

}
}

这是logcat
04-29 02:04:05.803 15719-15719/hivemind.com.ladies d/viewrootimpl:viewpostimeinputstage进程指针0 04-29 02:04:05.983 15719-15719/hivemind.com.ladies d/viewrootimpl:viewpostimeinputstage进程指针1 04-29 02:04:05.983 15719-17866/hivemind.com.ladies i/system.out:thread-10038（apachehttplog）：issbsettingenabled falsethread-10038（apachehttplog）：isshipbuild true 04-29 02:04:05.993 15719-17866/hivemind.com.i/system.out:thread-10038（apachehttplog）：getdebuglevel 0x4f4c thread-10038（apachehttplog）：智能绑定设置为false thread-10038（apachehttplog）：智能绑定设置为false，ship\u build为true，日志到文件为false，dbg为false，调试级别（1-低，2-中，3-高）是1 04-29 02:04:08.993 15719-17866/hivemind.com.ladies i/system.out:asynctask#5 calls detatch（）04-29 02:04:08.993 15719-17866/hivemind.com.ladies w/system.err:org.apache.http.conn.httphostconnectexception:连接到http://172.16.21.5 refused 在org.apache.http.impl.conn.defaultclientconnectionoperator.openconnection（defaultclientconnectionoperator。java:248)在org.apache.http.impl.conn.abstractpoolentry.open（abstractpoolentry.org.apache.http.impl.conn.abstractpoolentry.open）上。java:172)在org.apache.http.impl.conn.abstractpooledconnadapter.open（abstractpooledconnadapter。java:130)在org.apache.http.impl.client.defaultrequestdirector.executeoriginal（defaultrequestdirector。java:1337)在org.apache.http.impl.client.defaultrequestdirector.execute（defaultrequestdirector。java:705)在org.apache.http.impl.client.abstracthttpclient.execute（abstracthttpclient。java:578)在org.apache.http.impl.client.abstracthttpclient.execute（abstracthttpclient。java:494)在org.apache.http.impl.client.abstracthttpclient.execute（abstracthttpclient。java:472)在hivemind.com.ladies.authentication.registeractivity$asyncdataclass.doinbackground（registeractivity。java:116)在hivemind.com.ladies.authentication.registeractivity$asyncdataclass.doinbackground（registeractivity。java:90)在android.os.asynctask$2.call（asynctask。java:295)在java.util.concurrent.futuretask.run（futuretask。java:237)在android.os.asynctask$serialexecutor$1.run（asynctask。java:234)在java.util.concurrent.threadpoolexecutor.runworker（threadpoolexecutor。java:1113)在java.util.concurrent.threadpoolexecutor$worker.run（threadpoolexecutor。java:588)在java.lang.thread.run（线程。java:818)原因：java.net.connectexception:5000ms后连接到/172.16.21.5（端口80）失败：isconnected失败：ehostunach（没有到的路由）主机）在libcore.io.iobridge.isconnected（iobridge。java:234)在libcore.io.iobridge.connecterrno（iobridge。java:171)在libcore.io.iobridge.connect（iobridge。java:122)在java.net.plainsocketimpl.connect（plainsocketimpl。java:183)在java.net.plainsocketimpl.connect（plainsocketimpl。java:452)在java.net.socket.connect（socket。java:884)在org.apache.http.conn.scheme.plainsocketfactory.connectsocket（plainsocketfactory）。java:124)在org.apache.http.impl.conn.defaultclientconnectionoperator.openconnection（defaultclientconnectionoperator。java:193) ... 另外15个原因：android.system.errnoexception:isconnected失败：libcore.io.iobridge.isconnected（iobridge）处的ehostunach（没有到主机的路由）。java:223) ... 22更多04-29 02:04:09.003 15719-15719/hivemind.com.ladies i/system.out:结果值：04-29 02:04:09.053 15719-15719/hivemind.com.ladies d/viewrootimpl:#1 mview=android.widget.linearlayout{29e5577 v.e。。。。。。一。0,0-0,0}04-29 02:04:09.133 15719-15719/hivemind.com.d/viewrootimpl:msg\u resized\u report:ci=rect（0，0-0，0）vi=rect（0，0-0，0）or=1 04-29 02:04:09.143 15719-15719/hivemind.com.ladies w/displaylistcanvas:displaylistcanvas在未绑定的rendernode上启动（没有mowningview）04-29 02:04:12.553 15719-15719/hivemind.com.ladies d/viewrootimpl:#3 mview=null