DEVOCEAN

dependencies {
    implementation 'com.android.volley:volley:1.2.0'
}

<uses-permission android:name="android.permission.INTERNET" />

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
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;

public class MainActivity extends Activity {
    private TextView responseText;

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

        responseText = findViewById(R.id.responseText);

        // Volley의 요청 큐 초기화
        RequestQueue queue = Volley.newRequestQueue(this);

        // 네트워크 요청 생성
        String url = "http://127.0.0.1/posts/1";
        StringRequest stringRequest = new StringRequest(Request.Method.GET, url,
            new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {
                    // 요청 성공 시 응답 처리
                    responseText.setText("응답: " + response);
                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    // 요청 실패 시 에러 처리
                    responseText.setText("에러: " + error.getMessage());
                }
            });

        // 요청 큐에 요청 추가
        queue.add(stringRequest);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/responseText"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="응답을 여기에 표시합니다."
        android:textSize="18sp" />

</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp">

    <EditText
        android:id="@+id/editText_search"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="책 검색" />

    <Button
        android:id="@+id/button_search"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="검색" />

    <ProgressBar
        android:id="@+id/progressBar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:visibility="gone" />

    <ListView
        android:id="@+id/listView_books"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:divider="@android:color/darker_gray"
        android:dividerHeight="1dp" />

    <Button
        android:id="@+id/button_load_more"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="더보기"
        android:layout_centerHorizontal="true"
        android:layout_alignParentBottom="true"
        android:layout_margin="16dp"
        android:visibility="gone" />

    <TextView
        android:id="@+id/textView_noData"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="데이터가 없습니다."
        android:textSize="20sp"
        android:visibility="gone" />

</LinearLayout>

import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;
import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
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.JsonObjectRequest;
import com.android.volley.toolbox.Volley;
import com.book.Book;
import com.book.BookAdapter;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import uxpp.uc.R;

public class MagicMenuBookSearchWebViewActivity extends AppCompatActivity {

    private static final String BASE_URL = "https://dapi.kakao.com/v3/search/book";
    private static final String API_KEY = "[자신이 발급한 kakao openapi key]";

    private EditText searchEditText;
    private Button searchButton;
    private ListView listView;
    private ProgressBar progressBar;
    private TextView noDataTextView;
    private Button loadMoreButton; // 추가 데이터를 불러오는 버튼

    private RequestQueue requestQueue;
    private BookAdapter adapter;
    private List<Book> bookList;
    private int page = 1;
    private boolean isLoading = false;
    private boolean hasMoreData = true;
    private String currentQuery = "";

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

        searchEditText = findViewById(R.id.editText_search);
        searchButton = findViewById(R.id.button_search);
        listView = findViewById(R.id.listView_books);
        progressBar = findViewById(R.id.progressBar);
        noDataTextView = findViewById(R.id.textView_noData);
        loadMoreButton = findViewById(R.id.button_load_more); // 더보기 버튼

        requestQueue = Volley.newRequestQueue(this);
        bookList = new ArrayList<>();
        adapter = new BookAdapter(this, R.layout.webview_magic_list_item_book, bookList);
        listView.setAdapter(adapter);

        searchButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (!isLoading) {
                    currentQuery = searchEditText.getText().toString();
                    if (!TextUtils.isEmpty(currentQuery)) {
                        initData();
                        getJSONData(currentQuery);
                    }
                }
            }
        });

        loadMoreButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (!isLoading) {
                    loadMoreData();
                }
            }
        });
    }

    private void initData() {
        page = 1;
        hasMoreData = true;
        bookList.clear();
        adapter.notifyDataSetChanged();
        isLoading = false;
        noDataTextView.setVisibility(View.GONE);
        loadMoreButton.setVisibility(View.GONE);
    }

    private void getJSONData(String query) {
        if (isLoading) {
            return;
        }
        isLoading = true;
        progressBar.setVisibility(View.VISIBLE);

        String url = BASE_URL + "?query=" + query + "&size=10&page=" + page;

        JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url, null,
                new Response.Listener<JSONObject>() {
                    @Override
                    public void onResponse(JSONObject response) {
                        try {
                            JSONArray documents = response.getJSONArray("documents");
                            if (documents.length() > 0) {
                                for (int i = 0; i < documents.length(); i++) {
                                    JSONObject bookObject = documents.getJSONObject(i);

                                    String title = bookObject.getString("title");
                                    JSONArray authorsArray = bookObject.optJSONArray("authors");
                                    String author = (authorsArray != null && authorsArray.length() > 0) ? authorsArray.getString(0) : "";
                                    String thumbnail = bookObject.optString("thumbnail", "");
                                    int price = bookObject.optInt("price", 0);
                                    int sale_price = bookObject.optInt("sale_price", 0);

                                    Book book = new Book(title, author, thumbnail, price, sale_price);
                                    bookList.add(book);
                                }
                                adapter.notifyDataSetChanged();
                                isLoading = false;
                                progressBar.setVisibility(View.GONE);
                                page++; // 페이지 증가

                                // Check if it's the last page based on the 'is_end' field
                                boolean isEnd = response.getJSONObject("meta").getBoolean("is_end");
                                if (isEnd) {
                                    hasMoreData = false;
                                    if (page == 1) {
                                        noDataTextView.setText("데이터가 없습니다.");
                                    } else {
                                        noDataTextView.setText("마지막 데이터에 도달했습니다.");
                                    }
                                    noDataTextView.setVisibility(View.VISIBLE);
                                    loadMoreButton.setVisibility(View.GONE); // 더보기 버튼 숨김
                                } else {
                                    // 추가 데이터가 있는 경우 더보기 버튼 표시
                                    loadMoreButton.setVisibility(View.VISIBLE);
                                }
                            } else {
                                if (page == 1) {
                                    noDataTextView.setText("데이터가 없습니다.");
                                    noDataTextView.setVisibility(View.VISIBLE);
                                } else {
                                    hasMoreData = false;
                                    noDataTextView.setText("마지막 데이터에 도달했습니다.");
                                    noDataTextView.setVisibility(View.VISIBLE);
                                }
                                progressBar.setVisibility(View.GONE);
                            }
                        } catch (JSONException e) {
                            e.printStackTrace();
                            isLoading = false;
                            progressBar.setVisibility(View.GONE);
                        }
                    }
                },
                new Response.ErrorListener() {
                    @Override
                    public void onErrorResponse(VolleyError error) {
                        isLoading = false;
                        progressBar.setVisibility(View.GONE);
                        String errorMessage = (error != null && error.getMessage() != null) ? error.getMessage() : "알 수 없는 오류";
                        noDataTextView.setText("요청 실패: " + errorMessage);
                        noDataTextView.setVisibility(View.VISIBLE);
                    }
                }
        ) {
            @Override
            public Map<String, String> getHeaders() {
                Map<String, String> headers = new HashMap<>();
                headers.put("Authorization", "KakaoAK " + API_KEY);
                return headers;
            }
        };

        requestQueue.add(request);
    }

    private void loadMoreData() {
        if (!isLoading) {
            getJSONData(currentQuery);
        }
    }
}