import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.extensions.java6.auth.oauth2.AuthorizationCodeInstalledApp;
import com.google.api.client.extensions.jetty.auth.oauth2.LocalServerReceiver;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.gson.GsonFactory;
import com.google.api.client.util.store.FileDataStoreFactory;
import com.google.api.services.sheets.v4.Sheets;
import com.google.api.services.sheets.v4.SheetsScopes;
import com.google.api.services.sheets.v4.model.ValueRange;

import java.io.*;
import java.security.GeneralSecurityException;
import java.util.Collections;
import java.util.List;

/**
 * 官方对接文档地址：https://developers.google.com/sheets/api/quickstart/java?hl=it
 * 示例Google Sheet地址：https://docs.google.com/spreadsheets/d/1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgvE2upms/edit#gid=0
 *
 * @author Lenjor
 * @version 1.0
 * @date 2021/1/26 10:56
 */
public class GoogleSheet {
    private static final String APPLICATION_NAME = "Quickstart";
    private static final JsonFactory JSON_FACTORY = GsonFactory.getDefaultInstance();
    private static final String TOKENS_DIRECTORY_PATH = "tokens";

    private static final List<String> SCOPES = Collections.singletonList(SheetsScopes.SPREADSHEETS_READONLY);
    /**
     * TODO 下载的应用授权文件，这里记得换成自己的授权文件
     */
    private static final String CREDENTIALS_FILE_PATH = "C:\\Users\\Efun\\Desktop\\credentials.json";

    /**
     * Creates an authorized Credential object.
     *
     * @param HTTP_TRANSPORT The network HTTP Transport.
     * @return An authorized Credential object.
     * @throws IOException If the credentials.json file cannot be found.
     */
    private static Credential getCredentials(final NetHttpTransport HTTP_TRANSPORT) throws IOException {
        InputStream in = new FileInputStream(new File(CREDENTIALS_FILE_PATH));
        if (in == null) {
            throw new FileNotFoundException("Resource not found: " + CREDENTIALS_FILE_PATH);
        }
        GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in));

        // Build flow and trigger user authorization request.
        GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
                HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES)
                .setDataStoreFactory(new FileDataStoreFactory(new java.io.File(TOKENS_DIRECTORY_PATH)))
                .setAccessType("offline")
                .build();
        LocalServerReceiver receiver = new LocalServerReceiver.Builder().setPort(8888).build();
        return new AuthorizationCodeInstalledApp(flow, receiver).authorize("user");
    }

    public static void main(String[] args) throws GeneralSecurityException, IOException {
        // Build a new authorized API client service.
        final NetHttpTransport HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
        final String spreadsheetId = "1BxiMVs0XRA5nFMdKvBdBZjgmUUqptlbs74OgvE2upms";    // 这个是官方的 spreadsheetId，读取自己的Google Sheet换成对应ID即可
        final String range = "Class Data!A1:F10"; // 读取的表格范围，命名规范： {sheet表名称}!{开始单元格}:{结束单元格}
        Sheets service = new Sheets.Builder(HTTP_TRANSPORT, JSON_FACTORY, getCredentials(HTTP_TRANSPORT))
                .setApplicationName(APPLICATION_NAME)
                .build();
        ValueRange response = service.spreadsheets().values()
                .get(spreadsheetId, range)
                .execute();
        List<List<Object>> values = response.getValues();
        if (values == null || values.isEmpty()) {
            System.out.println("No data found.");
        } else {
            for (List row : values) {
                for (int i = 0; i < row.size(); i++) {
                    System.out.print(row.get(i) + "\t\t");
                }
                System.out.println("");
            }
        }
    }
}