java - Apache POI 单元格类型错误

Question

我正在尝试使用 Apache POI 读取一个 excel 文件，该文件将有两列:标题和语言。标题将包含一些某种语言的句子，语言栏将为空。 Apache POI 读取标题中的句子后，应将其保存在变量中，然后调用语言检测库 ( https://code.google.com/archive/p/language-detection/ )。我特别在有 case 语句的行上遇到错误

import java.util.ArrayList; 
import com.cybozu.labs.langdetect.Detector; 
import com.cybozu.labs.langdetect.DetectorFactory; 
import com.cybozu.labs.langdetect.Language;
import java.util.Scanner;
import com.cybozu.labs.langdetect.LangDetectException; 

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Iterator;

import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

public class LangDetectSample {
    public static void main(String[] args) throws IOException, LangDetectException {
        String excelFilePath = "C:\\LD\\Books.xlsx";
        FileInputStream inputStream = new FileInputStream(new File(excelFilePath));

        Workbook workbook = new XSSFWorkbook(inputStream);
        Sheet firstSheet = workbook.getSheetAt(0); // Assuming that the data is sheet in one
        Iterator<Row> iterator = firstSheet.iterator();
        DataFormatter formatter = new DataFormatter();

        LangDetectSample lang = new LangDetectSample();

        //creating variables
        String title;
        String language;
        int rowNumber;

        //Blank workbook
        XSSFWorkbook wb = new XSSFWorkbook(); //new workbook //fixed

        //Create a blank sheet
        Sheet sheet1 = wb.createSheet("Predicted language"); //fixed
        while (iterator.hasNext())
        {
            Row nextRow = iterator.next();
            rowNumber = nextRow.getRowNum();
            Cell cell = nextRow.getCell(2); // title is in column 2
            switch (cell.getCellType()) {
                case Cell.CELL_TYPE_STRING:
                    title = cell.getStringCellValue();
                    break;
        case Cell.CELL_TYPE_BOOLEAN:

        title = formatter.formatCellValue(cell);
        break;


        case Cell.CELL_TYPE_NUMERIC:

        title = formatter.formatCellValue(cell);
        break; 
            }

            System.out.print(title);

            //Title should now have the title.
            // Call the language detector:
            language = lang.detect(title);
            System.out.println(lang);

            // if language detected, attempt to output the result to the new excel file with the following commands:

            // Write the title, language

            Row row = sheet1.createRow(rowNumber); //changed var
            Cell cell2 = row.createCell(2); //changed variable name
            cell.setCellValue(title);
            Cell cell3 = row.createCell(3);
            cell.setCellValue(language);
        }
        try {
            //Write the workbook in file system
            FileOutputStream out = new FileOutputStream(new File("title-language.xlsx"));
            workbook.write(out);
            out.close();
        } catch (Exception e)

        {
            e.printStackTrace();
        }
        workbook.close();
        inputStream.close();
    }

    public void init(String profileDirectory) throws LangDetectException {
        DetectorFactory.loadProfile(profileDirectory);
    }

    public String detect(String text) throws LangDetectException {
        DetectorFactory.loadProfile("C:\\LD\\profiles");
        Detector detector = DetectorFactory.create();
        detector.append(text);
        return detector.detect();
    }

    public ArrayList detectLangs(String text) throws LangDetectException {
        Detector detector = DetectorFactory.create();
        detector.append(text);
        return detector.getProbabilities();
    }
}

我收到的错误是

变量标题可能尚未初始化

Answer 1

对于检查 boolean 值的第一个错误，请保留“Object”类的可用值，例如

Object title;

switch (cell.getCellType()) {
case Cell.CELL_TYPE_BOOLEAN: 
        title = cell.getBooleanCellValue();  
        break;
}

对于第二个错误，java读取“double”中的默认单元格值 数据类型格式，因此您需要使用以下方法将其转换为文本/字符串...

Object title="";

title = new DecimalFormat("0").format(Cell.getNumericCellValue());

希望这对您有帮助...

谢谢