package com.example.contects;


import android.content.Intent;
import android.os.Bundle;
import android.os.StrictMode;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;

import java.io.IOException;

import okhttp3.FormBody;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;

public class upload_insert extends AppCompatActivity {
    EditText et_name, et_exp, et_url;
final static int REQ_CODE_UPLOAD = 100;
    Button btn_upload = (Button) findViewById(R.id.btn_up);

@Override
    protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_upload_insert);
        StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
                .detectDiskReads()
                .detectDiskReads()
                .detectNetwork()
                .penaltyLog().build()
        );

et_name = (EditText) findViewById(R.id.et_name);
et_exp = (EditText) findViewById(R.id.et_exp);
et_url = (EditText) findViewById(R.id.et_url);

btn_upload.setOnClickListener(new View.OnClickListener() {
@Override
            public void onClick(View v) {
                Intent it1 = new Intent(upload_insert.this,this.getClass());
                startActivityForResult(it1,REQ_CODE_UPLOAD);
            }
        });
    }

private boolean check_data() { // 밑의 액티비티에서 확인
        boolean check = false;
if(et_name.getText().toString().equals("")) {
            Toast.makeText(upload_insert.this,"이름을 입력하세요.",Toast.LENGTH_SHORT).show();
            check = false;
        }
else if(et_exp.getText().toString().equals("")) {
            Toast.makeText(upload_insert.this,"설명을 입력하세요.",Toast.LENGTH_SHORT).show();
            check = false;
        }
else if(et_url.getText().toString().equals("")) {
            Toast.makeText(upload_insert.this,"이름을 입력하세요.",Toast.LENGTH_SHORT).show();
            check = false;
        }
else {
            check = true;
        }
return check;
    }


@Override
    protected void onActivityResult(int requestCode, @Nullable int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);

if(requestCode == REQ_CODE_UPLOAD) {
if(check_data()) {
                String urlStr = "http://172.30.1.21/web/db_insert1.php";
if(data_insert(urlStr)) {
                    Toast.makeText(getApplicationContext(),"DB 입력 성공",Toast.LENGTH_LONG).show();
                } else {
                    Toast.makeText(getApplicationContext(), "DB 입력 실패", Toast.LENGTH_LONG).show();
                }

            }
        }
    }


private boolean data_insert(String url) {
        OkHttpClient client = new OkHttpClient();

        RequestBody formBody = new FormBody.Builder()
                .add("id",et_name.getText().toString())
                .add("exp",et_exp.getText().toString())
                .add("url",et_url.getText().toString())
                .build();

        Request request = new Request.Builder()
                .url(url)
                .post(formBody)
                .build();

        Response response = null;
try {
            response = client.newCall(request).execute();

if(response.code() == 200 || response.code() == 201) {
                String res = response.body().string();
return res.equals("Success");
            }

        } catch (IOException e) {
            Log.e("TAG","Other Error" + e.getLocalizedMessage());
        }
return false;
    }
}

코드가 이렇게 되어있는데 

        btn_upload.setOnClickListener(new View.OnClickListener() {
@Override
            public void onClick(View v) {
                Intent it1 = new Intent(upload_insert.this,this.getClass());
                startActivityForResult(it1,REQ_CODE_UPLOAD);
            }
        });

버튼을 누르면 

    @Override
    protected void onActivityResult(int requestCode, @Nullable int resultCode, @Nullable Intent data) {
super.onActivityResult(requestCode, resultCode, data);

if(requestCode == REQ_CODE_UPLOAD) {
if(check_data()) {
                String urlStr = "http://172.30.1.21/web/db_insert1.php";
if(data_insert(urlStr)) {
                    Toast.makeText(getApplicationContext(),"DB 입력 성공",Toast.LENGTH_LONG).show();
                } else {
                    Toast.makeText(getApplicationContext(), "DB 입력 실패", Toast.LENGTH_LONG).show();
                }

            }
        }
    }

액티비티 내에서 인텐트 실행해야함

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