java-poi操作笔记

row表示行，cell表示row中的第几个cell

package sample.Utils;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.Workbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;public  class excelUtils {//读取excelpublic 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-ddcellValue = 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;}public static void writeExcel(String filePath,String sheet1Name,int row1,int one,int two,int three,int four, String onecontent,String twocontent,String threecontent,String fourcontent){FileInputStream inputStream = null;try {inputStream = new FileInputStream(filePath);} catch (FileNotFoundException e) {e.printStackTrace();}Workbook workbook = null;try {workbook = new XSSFWorkbook(inputStream);} catch (IOException e) {e.printStackTrace();}Sheet sheet = workbook.getSheet(sheet1Name);Row row = sheet.createRow(row1);Cell cell1 =  row.createCell(one);cell1.setCellValue(onecontent);Cell cell24 =  row.createCell(two);cell24.setCellValue(twocontent);Cell cell25 =  row.createCell(three);cell25.setCellValue(threecontent);Cell cell26 =  row.createCell(four);cell26.setCellValue(fourcontent);// 写入数据try (FileOutputStream outputStream = new FileOutputStream(filePath)) {workbook.write(outputStream);} catch (IOException e) {e.printStackTrace();} finally {try {if (workbook != null) {workbook.close();}} catch (IOException e) {e.printStackTrace();}}}}