JAVA读取、写入Excel表格(含03版)

引言

工作中可能会遇到对Excel读取和写入，如果我们自己手动写的话，会很麻烦，但是Apache中有poi工具类。poi工具类封装好了对于Excel读取和写入，我们需要用的时候，直接调用该方法就好了。
注:03和07的写法不一致。
区别如下

        // HSSFWorkbook 2003的excel .xls,XSSFWorkbook导入2007的excel   .xlsx
        HSSFWorkbook workbook=new HSSFWorkbook(new FileInputStream(new File(file)));
        XSSFWorkbook workbook=new XSSFWorkbook(new FileInputStream(new File(file))));

代码实现

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

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.xssf.usermodel.XSSFWorkbook;

import com.alibaba.fastjson.JSONObject;



/**
 * 
* Title: excelTest
* Description: excel表格读取
* 注意:引用poi 架包版本要一致
* 如:
* poi-3.13.jar
* poi-ooxml-3.13.jar
* poi-ooxml-schemas-3.13.jar
* poi-scratchpad-3.13.jar
* 这些架包版本随意
* stax-api.jar
* xmlbeans.jar
* dom4j.jar
* Version:1.0.0  
* @author pancm
 */
public class excelTest {

    private static final String path="D:\\file\\test.xlsx"; 
    private static final String path1="D:\\file\\test1.xlsx"; 

    public static void main(String[] args) throws FileNotFoundException, IOException {
        readExcel(path);
        writeExcel(path1);
    }

    /**
     * 读取Excel表格内容
     * @throws FileNotFoundException
     * @throws IOException
     */
    @SuppressWarnings({ "rawtypes", "unchecked" })
    private static void readExcel(String str) throws FileNotFoundException, IOException{
        File file=new File(str);
        // HSSFWorkbook 2003的excel .xls,XSSFWorkbook导入2007的excel   .xlsx
//      HSSFWorkbook workbook=new HSSFWorkbook(new FileInputStream(new File(file)));
        XSSFWorkbook workbook=new XSSFWorkbook(new FileInputStream(file));
         Sheet sheet=workbook.getSheetAt(0);//读取第一个 sheet
         List list= new ArrayList<>();
         Row row=null;
         int count=sheet.getPhysicalNumberOfRows();
        //逐行处理 excel 数据
        for (int i = 1; i <count; i++) {
             JSONObject json=new JSONObject();
              row=sheet.getRow(i);
             Cell cell0 = row.getCell(0);
             //设置取值为String
             //整数数据要转，否则会变成浮点数
            cell0.setCellType(Cell.CELL_TYPE_STRING);
            Cell cell1 = row.getCell(1); 
            cell1.setCellType(Cell.CELL_TYPE_STRING);
            json.put("Id",cell0.toString()); //编号
            json.put("Name",cell1.toString()); //名称
            list.add(json);
            System.out.println("json:"+json);
        }
        workbook.close();
        System.out.println("list:"+list);
    }

    /**
     * 写入Excel表格内容
     * @throws FileNotFoundException
     * @throws IOException
     */
    @SuppressWarnings({ "resource", "rawtypes", "unchecked" })
    private static void writeExcel(String str) throws FileNotFoundException, IOException{
        File file=new File(str);
        // HSSFWorkbook 2003的excel .xls,XSSFWorkbook导入2007的excel   .xlsx
//      HSSFWorkbook workbook=new HSSFWorkbook(new FileInputStream(new File(file)));
        XSSFWorkbook workbook=new XSSFWorkbook(new FileInputStream(file));
        List resultList =new ArrayList<>();

        Sheet sheet1 = workbook.createSheet();//创建 sheet 对象
        Row row = sheet1.createRow(0);//第一行，标题
        row.createCell(0).setCellValue("A");
        row.createCell(1).setCellValue("B");
        row.createCell(2).setCellValue("C");
        row.createCell(3).setCellValue("D");
        row.createCell(4).setCellValue("E");
        //拼接数据
        for(int i=1;i<=10;i++){
            JSONObject json1=new JSONObject();
            json1.put("A", i);
            json1.put("B", i*2);
            json1.put("C", i*3);
            json1.put("D", i*4);
            json1.put("E", i*5);
            resultList.add(json1);
        }
        System.out.println("resultList:"+resultList);
        Row row1;
        for (int i = 1, len = resultList.size(); i <=len; i++) {//循环创建数据行
            //因为第一行已经设置了，所以从第二行开始
            row1 = sheet1.createRow(i);
            JSONObject json=(JSONObject) resultList.get(i-1);
            row1.createCell(0).setCellValue(json.getString("A"));
            row1.createCell(1).setCellValue(json.getString("B"));
            row1.createCell(2).setCellValue(json.getString("C"));
            row1.createCell(3).setCellValue(json.getString("D"));
            row1.createCell(4).setCellValue(json.getString("E"));
        }
        FileOutputStream fos = new FileOutputStream(path1); 
        workbook.write(fos);//写文件
        fos.close();
        System.out.println("写入成功！");
    }
}