无法在android中通过截击请求传递参数

嗨，我无法通过截击请求传递参数。 我目前使用GET方法。但当我传递参数时，它显示“null error”

我尝试过的
下面是我的活动代码。 我尝试传递“dayorder”参数，结果我尝试获取特定的“dayorder的时段”作为结果数组，并在TextView中打印它

public class AttendanceActivity extends AppCompatActivity {

private TextView today;
private TextView todayDate;
private TextView textViewResult;
private String dayorder;


protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_attendance);

    today = (TextView) findViewById(R.id.textDay);
    todayDate = (TextView) findViewById(R.id.textDate);
    textViewResult=(TextView)findViewById(R.id.textViewResult);
    chechDate();
}

public void chechDate(){
        Calendar rightNow = Calendar.getInstance();
        if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.MONDAY){
            today.setText("Monday");
        }else if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.TUESDAY){
            today.setText("Tuesday");
        }else if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.WEDNESDAY){
            today.setText("Wednesday");
        }else if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.THURSDAY){
            today.setText("Thursday");
        }else if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.FRIDAY){
            today.setText("Friday");
        }else if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY){
            today.setText("Saturday");
        } else if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY){
            today.setText("Sunday");
        }else{
            today.setText("Unable to get day");
        }

        Calendar c = Calendar.getInstance();
        System.out.println("Current time => " + c.getTime());

        SimpleDateFormat df = new SimpleDateFormat("dd-MMM-yyyy");
        String formattedDate = df.format(c.getTime());

    dayorder=today.toString();
        todayDate.setText(formattedDate);

    getData();


    }

private void getData() {

    dayorder = today.getText().toString().trim();



    StringRequest stringRequest = new StringRequest(Request.Method.GET, SUBJECT_URL,
            new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    if (response.trim().equals("success")) {
                        Toast.makeText(AttendanceActivity.this, response, Toast.LENGTH_LONG).show();

                        showJSON(response);

                    } else {
                        Toast.makeText(AttendanceActivity.this, response, Toast.LENGTH_LONG).show();


                    }
                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Toast.makeText(AttendanceActivity.this, "Unable to connect. Please connect to Internet!", Toast.LENGTH_LONG).show();
                }
            }) {
        @Override
        protected Map<String, String> getParams(){
            Map<String, String> map = new HashMap<>();
            map.put(KEY_DAYORDER, dayorder);
            return map;
        }
    };

    RequestQueue requestQueue = Volley.newRequestQueue(this);
    requestQueue.add(stringRequest);
}

private void showJSON(String response){
    String period1="";
    String period2="";
    String period3="";
    String period4="";
    String period5="";
    String period6="";
    String period7="";

    try {
        JSONObject jsonObject = new JSONObject(response);
        JSONArray result = jsonObject.getJSONArray(Config.JSON_SUBJECTARRAY);
        JSONObject collegeData = result.getJSONObject(0);
        period1 = collegeData.getString(Config.KEY_PERIOD1);
        period2 = collegeData.getString(Config.KEY_PERIOD2);
        period3 = collegeData.getString(Config.KEY_PERIOD3);
        period4 = collegeData.getString(Config.KEY_PERIOD4);
        period5 = collegeData.getString(Config.KEY_PERIOD5);
        period6 = collegeData.getString(Config.KEY_PERIOD6);
        period7 = collegeData.getString(Config.KEY_PERIOD7);

    } catch (JSONException e) {
        e.printStackTrace();
    }
    textViewResult.setText(period1+period2+period3+period4+period5+period6+period7);
}

公共课堂出席活动扩展了AppCompative活动{
今日私人文本视图；
私有文本视图todayDate；
私有文本视图文本视图结果；
私有字符串日顺序；
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity\u考勤）；
今天=（TextView）findViewById（R.id.textDay）；
todayDate=（TextView）findViewById（R.id.textDate）；
textViewResult=（TextView）findViewById（R.id.textViewResult）；
chechDate（）；
}
公共无效支票（）{
Calendar rightNow=Calendar.getInstance（）；
if（rightNow.get（Calendar.DAY\u OF_WEEK）=Calendar.MONDAY）{
今天.setText（“星期一”）；
}else if（rightNow.get（Calendar.DAY\u OF_WEEK）=Calendar.周二）{
今天。setText（“星期二”）；
}else if（rightNow.get（Calendar.DAY\u OF_WEEK）=Calendar.周三）{
今天。setText（“星期三”）；
}else if（rightNow.get（Calendar.DAY\u OF_WEEK）=Calendar.周四）{
今天。setText（“星期四”）；
}else if（rightNow.get（Calendar.DAY\u OF_WEEK）=Calendar.FRIDAY）{
今天。setText（“星期五”）；
}else if（rightNow.get（Calendar.DAY\u OF_WEEK）=Calendar.SATURDAY）{
今天.setText（“星期六”）；
}else if（rightNow.get（Calendar.DAY\u OF_WEEK）=Calendar.SUNDAY）{
今天。setText（“星期日”）；
}否则{
today.setText（“无法获取日期”）；
}
Calendar c=Calendar.getInstance（）；
System.out.println（“当前时间=>”+c.getTime（））；
SimpleDataFormat df=新的SimpleDataFormat（“dd MMM yyyy”）；
字符串formattedDate=df.format（c.getTime（））；
dayorder=today.toString（）；
todayDate.setText（格式化日期）；
getData（）；
}
私有void getData（）{
dayorder=today.getText（）.toString（）.trim（）；
StringRequest StringRequest=新的StringRequest（Request.Method.GET，SUBJECT\u URL，
新的Response.Listener（）{
@凌驾
公共void onResponse（字符串响应）{
if（response.trim（）.equals（“success”））{
Toast.makeText（AttendanceActivity.this、response、Toast.LENGTH_LONG.show（）；
showJSON（响应）；
}否则{
Toast.makeText（AttendanceActivity.this、response、Toast.LENGTH_LONG.show（）；
}
}
},
新的Response.ErrorListener（）{
@凌驾
公共无效onErrorResponse（截击错误）{
Toast.makeText（AttendanceActivity.this，“无法连接。请连接到Internet！”，Toast.LENGTH\u LONG.show（）；
}
}) {
@凌驾
受保护的映射getParams（）{
Map Map=newhashmap（）；
图.put（键_DAYORDER，DAYORDER）；
返回图；
}
};
RequestQueue RequestQueue=Volley.newRequestQueue（this）；
添加（stringRequest）；
}
私有void showJSON（字符串响应）{
字符串周期1=“”；
字符串周期2=“”；
字符串周期3=“”；
字符串周期4=“”；
字符串周期5=“”；
字符串周期6=“”；
字符串周期7=“”；
试一试{
JSONObject JSONObject=新JSONObject（响应）；
JSONArray result=jsonObject.getJSONArray（Config.JSON_SUBJECTARRAY）；
JSONObject collegeData=result.getJSONObject（0）；
period1=collegeData.getString（Config.KEY\u period1）；
period2=collegeData.getString（Config.KEY\u period2）；
period3=collegeData.getString（Config.KEY\u period3）；
period4=collegeData.getString（Config.KEY\u period4）；
period5=collegeData.getString（Config.KEY\u period5）；
period6=collegeData.getString（Config.KEY\u period6）；
period7=collegeData.getString（Config.KEY\u period7）；
}捕获（JSONException e）{
e、 printStackTrace（）；
}
textViewResult.setText（period1+period2+period3+period4+period5+period6+period7）；
}

---

}

在getRequest中，您通过Url提供参数？“paramKey=”value

为了你的案子

StringRequest stringRequest = new StringRequest(Request.Method.GET, SUBJECT_URL?"KEY_DAYORDER="dayorder,
            new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    if (response.trim().equals("success")) {
                        Toast.makeText(AttendanceActivity.this, response, Toast.LENGTH_LONG).show();

                        showJSON(response);

                    } else {
                        Toast.makeText(AttendanceActivity.this, response, Toast.LENGTH_LONG).show();


                    }
                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Toast.makeText(AttendanceActivity.this, "Unable to connect. Please connect to Internet!", Toast.LENGTH_LONG).show();
                }
            }) };

StringRequest StringRequest=newstringrequest（Request.Method.GET，SUBJECT\u URL？）KEY\u DAYORDER=“DAYORDER，
新的Response.Listener（）{
@凌驾
公共void onResponse（字符串响应）{
if（response.trim（）.equals（“success”））{
Toast.makeText（AttendanceActivity.this、response、Toast.LENGTH_LONG.show（）；
showJSON（响应）；
}否则{
Toast.makeText（AttendanceActivity.this、response、Toast.LENGTH_LONG.show（）；
}
}
},
新的Response.ErrorListener（）{
@凌驾
公共无效onErrorResponse（截击错误）{
Toast.makeText（AttendanceActivity.this，“无法连接。请连接到Internet！”，Toast.LENGTH\u LONG.show（）；
}
}) };

在getRequest中，您通过Url提供参数？“paramKey=”value

为了你的案子

StringRequest stringRequest = new StringRequest(Request.Method.GET, SUBJECT_URL?"KEY_DAYORDER="dayorder,
            new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    if (response.trim().equals("success")) {
                        Toast.makeText(AttendanceActivity.this, response, Toast.LENGTH_LONG).show();

                        showJSON(response);

                    } else {
                        Toast.makeText(AttendanceActivity.this, response, Toast.LENGTH_LONG).show();


                    }
                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Toast.makeText(AttendanceActivity.this, "Unable to connect. Please connect to Internet!", Toast.LENGTH_LONG).show();
                }
            }) };

StringRequest StringRequest=newstringrequest（Request.Method.GET，SUBJECT\u URL？）KEY\u DAYORDER=“DAYORDER，
新的Response.Listener（）{
@凌驾
公共void onResponse（字符串响应）{
if（response.trim（）.equals（“success”））{
Toast.makeText（AttendanceActivity.this、response、Toast.LENGTH_LONG.show（）；
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;
import android.widget.Toast;

import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.ibm.icu.text.SimpleDateFormat;
import com.ibm.icu.util.Calendar;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.HashMap;
import java.util.Map;

import static com.example.vicky.module1.Config.KEY_DAYORDER;
import static com.example.vicky.module1.Config.KEY_PERIOD1;
import static com.example.vicky.module1.Config.SUBJECT_URL;

public class AttendanceActivity extends AppCompatActivity {
    private TextView today;
    private TextView todayDate;
    private TextView textViewResult;    
    private String dayorder;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_attendance);

    today = (TextView) findViewById(R.id.textDay);
    todayDate = (TextView) findViewById(R.id.textDate);
    textViewResult=(TextView)findViewById(R.id.textViewResult);

    chechDate();
}

public void chechDate(){
        Calendar rightNow = Calendar.getInstance();
        if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.MONDAY){
            today.setText("Monday");
        }else if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.TUESDAY){
            today.setText("Tuesday");
        }else if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.WEDNESDAY){
            today.setText("Wednesday");
        }else if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.THURSDAY){
            today.setText("Thursday");
        }else if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.FRIDAY){
            today.setText("Friday");
        }else if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY){
            today.setText("Saturday");
        } else if (rightNow.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY){
            today.setText("Sunday");
        }else{
            today.setText("Unable to get day");
        }
        Calendar c = Calendar.getInstance();
        System.out.println("Current time => " + c.getTime());
        SimpleDateFormat df = new SimpleDateFormat("dd-MMM-yyyy");
        String formattedDate = df.format(c.getTime());
        todayDate.setText(formattedDate);
    getData();
    }

private void getData(){
    dayorder = today.getText().toString().trim();

    StringRequest stringRequest = new StringRequest(Request.Method.POST, SUBJECT_URL,
            new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    Toast.makeText(AttendanceActivity.this,response,Toast.LENGTH_LONG).show();
                    showJSON(response);
                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Toast.makeText(AttendanceActivity.this,error.toString(),Toast.LENGTH_LONG).show();
                }
            }){
        @Override
        protected Map<String,String> getParams(){
            Map<String,String> params = new HashMap<String, String>();
            params.put(KEY_DAYORDER, dayorder);

            return params;
        }

    };

    RequestQueue requestQueue = Volley.newRequestQueue(this);
    requestQueue.add(stringRequest);
}

private void showJSON(String response){
    String period1="";
    String period2="";
    String period3="";
    String period4="";
    String period5="";
    String period6="";
    String period7="";

    try {
        Toast.makeText(AttendanceActivity.this, "showjson try method", Toast.LENGTH_SHORT).show();


        JSONObject jsonObject = new JSONObject(response);
        JSONArray result = jsonObject.getJSONArray(Config.JSON_SUBJECTARRAY);
        JSONObject collegeData = result.getJSONObject(0);
        period1 = collegeData.getString(KEY_PERIOD1);


        textViewResult.setText(period1);

    } catch (JSONException e) {
        e.printStackTrace();
    }

    }

}