Java 读取Excel 文件内容

在一个项目中，有一个需求，是把excel文件的内容转换为xml格式展示。在学习如何操作的过程中，首先是如何获取excel文件，其中操作的代码如下：

1.首先是导入需要的 jar, 下载地址：

2.代码实现：

package com.apusic;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
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;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

/**
 * Created by baizhuang on 2018-11-20.
 *
 * dsccription: 读取本地的一个excel文档，并输出到控制台
 */
public class ReadLocalExcel {

    //总行数
    private int totalRows = 0;
    //总列数
    private int totalCells = 0;
    //错误信息
    private  String errorInfo;

    private ReadLocalExcel(){

    }

    public int getTotalRows() {
        return totalRows;
    }

    public int getTotalCells() {
        return totalCells;
    }

    public String getErrorInfo() {
        return errorInfo;
    }

    //检查文件是否为excel或者为空
    public boolean validateExcel(String filePath){
        //检查文件格式
        if (filePath==null || !(UUtil.isExcel2003(filePath) || UUtil.isExcel2007(filePath))) {
            errorInfo = "不是excel格式";
            return false;
        }
        //检查文件是否存在
        File file = new File(filePath);
        if(file==null || !file.exists()){
            errorInfo = "文件不存在";
            return  false;
        }
        return  true;

    }


    public List<List<String>> read(String filePath){
        List<List<String>> dataList = new ArrayList<List<String>>();
        InputStream is = null;

        try {
            //验证文件
            if(!validateExcel(filePath)){
                System.out.println(errorInfo);
                return null;
            }

            //判断文件类型
            boolean isExcel2003 = true;
            if(UUtil.isExcel2007(filePath)){
                isExcel2003 = false;
            }

            //调用读取方法
            File file = new File(filePath);
            is = new FileInputStream(file);
            dataList = read(is,isExcel2003);
            is.close();

        }catch (Exception e ){

        }finally {

        }
        return  dataList;
    }


    public List<List<String>> read(InputStream inputStream,boolean isExcel2003) throws  Exception{
        List<List<String>> dataLst = null;

        Workbook wb = null;
        if(isExcel2003){
            wb = new HSSFWorkbook(inputStream);
        }else {
            wb = new XSSFWorkbook(inputStream);
        }

        dataLst =readWork(wb);
        return  dataLst;
    }

    public List<List<String>> readWork(Workbook wb){
        List<List<String>> dataList = new ArrayList<List<String>>();
        //得到第一个shell
        Sheet sheet =wb.getSheetAt(0);
        this.totalRows = sheet.getPhysicalNumberOfRows();
        if(this.totalRows>=1 && sheet.getRow(0)!=null){
            this.totalCells = sheet.getRow(0).getPhysicalNumberOfCells();
        }
        //循环excel的行
        for (int r=0;r<this.totalRows;r++){
            Row row = sheet.getRow(r);
            if(row == null){
                continue;
            }

            List<String> rowList = new ArrayList<String>();
            //循环excel的列
            for(int c=0;c<this.getTotalCells();c++){
                Cell cell = row.getCell(c);
                String cellValue = "";
                if(null !=cell){
                    //判断数据类型
                    switch (cell.getCellType()){
                        case HSSFCell.CELL_TYPE_NUMERIC: //数字
                            cellValue = cell.getNumericCellValue()+"";
                            break;
                        case HSSFCell.CELL_TYPE_STRING:  //字符串
                            cellValue = cell.getStringCellValue();
                            break;
                        case  HSSFCell.CELL_TYPE_BOOLEAN: //布尔
                            cellValue = cell.getBooleanCellValue()+"";
                            break;
                        case  HSSFCell.CELL_TYPE_FORMULA: //公式
                            cellValue = cell.getCellFormula()+"";
                            break;
                        case HSSFCell.CELL_TYPE_BLANK: //空
                            cellValue = "";
                            break;
                        case HSSFCell.CELL_TYPE_ERROR:  //故障
                            cellValue = "非法字符";
                            break;
                        default:
                            cellValue = "未知类型";
                            break;
                    }
                }
                rowList.add(cellValue);
            }
            dataList.add(rowList);
        }
        return  dataList;
    }




    public static void main(String[] args){
        ReadLocalExcel t = new ReadLocalExcel();

          //  List<List<String>> list  = t.read("D://a.xlsx");
        List<List<String>> list  = t.read("D:\\a.xlsx");
            if(list!=null){
                System.out.println("***************************************");
                for (int i=0;i<list.size();i++){
                    System.out.print("第"+i+"行：");
                    List<String> cellList = list.get(i);
                    for (int j=0;j<cellList.size();j++){
                        System.out.print("   "+cellList.get(j));
                    }
                    System.out.println();
                }
                System.out.println("***************************************");
            }


    }

}


class UUtil{
    public static boolean isExcel2003(String filePath){
        return  filePath.matches("^.+\\.(?i)(xls)$");
    }

    public static boolean isExcel2007(String filePath){
        return filePath.matches("^.+\\.(?i)(xlsx)$");
    }

}