Java代码如何操作Excel(xls、xlsx两种格式)呢?

java解析excel的实现思路

实现思路：
    使用Apache中的poi包中的相关信息
	 即可对excel进行操作
    如:
     import org.apache.poi.ss.usermodel.Workbook,对应Excel文档；
     import org.apache.poi.hssf.usermodel.HSSFWorkbook，对应xls格式的Excel文档；
     import org.apache.poi.xssf.usermodel.XSSFWorkbook，对应xlsx格式的Excel文档；
     import org.apache.poi.ss.usermodel.Sheet，对应Excel文档中的一个sheet；
     import org.apache.poi.ss.usermodel.Row，对应一个sheet中的一行；
     import org.apache.poi.ss.usermodel.Cell，对应一个单元格

一、引入相应的jar包
　　1.commons-collections4-4.1.jar
　　2.poi-3.9-20121203.jar
　　3.poi-examples-3.9-20121203.jar
　　4.poi-excelant-3.9-20121203.jar
　　5.poi-ooxml-3.9-20121203.jar
　　6.poi-ooxml-schemas-3.9-20121203.jar
　　7.poi-scratchpad-3.9-20121203.jar
　　8.xmlbeans-2.3.0.jar 

//编写相应的代码

package poi;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.Arraylist;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.DateUtil;
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 TestClass {

    public static void main(String[] args) {
        Workbook wb =null;
        Sheet sheet = null;
        Row row = null;
        List<Map<String,String>> list = null;
        String cellData = null;
        String filePath = "D:\\test20230212.xlsx";
        String columns[] = {"name","age","score"};
        wb = readExcel(filePath);
        if(wb != null){
            //用来存放表中数据
            list = new ArrayList<Map<String,String>>();
            //获取第一个sheet
            sheet = wb.getSheetAt(0);
            //获取最大行数
            int rownum = sheet.getPhysicalNumberOfRows();
            //获取第一行
            row = sheet.getRow(0);
            //获取最大列数
            int colnum = row.getPhysicalNumberOfCells();
            for (int i = 1; i<rownum; i++) {
                Map<String,String> map = new LinkedHashMap<String,String>();
                row = sheet.getRow(i);
                if(row !=null){
                    for (int j=0;j<colnum;j++){
                        cellData = (String) getCellFormatValue(row.getCell(j));
                        map.put(columns[j], cellData);
                    }
                }else{
                    break;
                }
                list.add(map);
            }
        }
        //遍历解析出来的list
        for (Map<String,String> map : list) {
            for (Entry<String,String> entry : map.entrySet()) {
                System.out.print(entry.getKey()+":"+entry.getValue()+",");
            }
            System.out.println();
        }

    }
    //读取excel
    public static Workbook readExcel(String filePath){
        Workbook wb = null;
        if(filePath==null){
            return null;
        }
        String extString = filePath.substring(filePath.lastIndexOf("."));
        InputStream is = null;
        try {
            is = new FileInputStream(filePath);
            if(".xls".equals(extString)){
                return wb = new HSSFWorkbook(is);
            }else if(".xlsx".equals(extString)){
                return wb = new XSSFWorkbook(is);
            }else{
                return wb = null;
            }
            
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return wb;
    }
    public static Object getCellFormatValue(Cell cell){
        Object cellValue = null;
        if(cell!=null){
            //判断cell类型
            switch(cell.getCellType()){
            case Cell.CELL_TYPE_NUMERIC:{
                cellValue = String.valueOf(cell.getNumericCellValue());
                break;
            }
            case Cell.CELL_TYPE_FORMULA:{
                //判断cell是否为日期格式
                if(DateUtil.isCellDateFormatted(cell)){
                    //转换为日期格式YYYY-mm-dd
                    cellValue = cell.getDateCellValue();
                }else{
                    //数字
                    cellValue = String.valueOf(cell.getNumericCellValue());
                }
                break;
            }
            case Cell.CELL_TYPE_STRING:{
                cellValue = cell.getRichStringCellValue().getString();
                break;
            }
            default:
                cellValue = "";
            }
        }else{
            cellValue = "";
        }
        return cellValue;
    }

}