本文实例讲述了Java实现Excel导入导出数据库的方法。分享给大家供大家参考，具体如下：
由于公司需求，想通过Excel导入数据添加到数据库中，而导入的Excel的字段是不固定的，使用得通过动态创建数据表，每个Excel对应一张数据表，怎么动态创建数据表，可以参考前面一篇《java使用JDBC动态创建数据表及SQL预处理的方法》。
下面主要讲讲怎么将Excel导入到数据库中，直接上代码：干货走起~~
ExcellToObjectUtil 类
主要功能是讲Excel中的数据导入到数据库中，有几个注意点就是
1.一般Excel中第一行是字段名称，不需要导入，所以从第二行开始计算
2.每列的匹配要和对象的属性一样
import java.io.IOException;
import java.text.DecimalFormat;
import java.util.ArrayList;
import java.util.List;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.poifs.filesystem.POIFSFileSystem;
import com.forenms.exam.domain.ExamInfo;
public class ExcellToObjectUtil {
//examId,realName,SFZ,user_card,sex,没有字段,assessment_project,admission_number,seat_number
/**
* 读取xls文件内容
*
* @return List<XlsDto>对象
* @throws IOException
* 输入/输出(i/o)异常
*/
public static List<ExamInfo> readXls(POIFSFileSystem poifsFileSystem) throws IOException {
// InputStream is = new FileInputStream(filepath);
HSSFWorkbook hssfWorkbook = new HSSFWorkbook(poifsFileSystem);
ExamInfo exam = null;
List<ExamInfo> list = new ArrayList<ExamInfo>();
// 循环工作表Sheet
for (int numSheet = 0; numSheet < hssfWorkbook.getNumberOfSheets(); numSheet++) {
HSSFSheet hssfSheet = hssfWorkbook.getSheetAt(numSheet);
if (hssfSheet == null) {
continue;
}
// 循环行Row
for (int rowNum = 1; rowNum <= hssfSheet.getLastRowNum(); rowNum++) {
HSSFRow hssfRow = hssfSheet.getRow(rowNum);
if (hssfRow == null) {
continue;
}
exam = new ExamInfo();
// 循环列Cell
HSSFCell examId = hssfRow.getCell(1);
if (examId == null) {
continue;
}
double id = Double.parseDouble(getValue(examId));
exam.setExamId((int)id);
// HSSFCell realName = hssfRow.getCell(2);
// if (realName == null) {
// continue;
// }
// exam.setRealName(getValue(realName));
// HSSFCell userCard = hssfRow.getCell(4);
// if (userCard == null) {
// continue;
// }
//
// exam.setUserCard(getValue(userCard));
HSSFCell admission_number = hssfRow.getCell(8);
if (admission_number == null) {
continue;
}
exam.setAdmission_number(getValue(admission_number));
HSSFCell seat_number = hssfRow.getCell(9);
if (seat_number == null) {
continue;
}
exam.setSeat_number(getValue(seat_number));
list.add(exam);
}
}
return list;
}
public static List<ExamInfo> readXlsForJS(POIFSFileSystem poifsFileSystem) throws IOException {
// InputStream is = new FileInputStream(filepath);
HSSFWorkbook hssfWorkbook = new HSSFWorkbook(poifsFileSystem);
ExamInfo exam = null;
List<ExamInfo> list = new ArrayList<ExamInfo>();
// 循环工作表Sheet
for (int numSheet = 0; numSheet < hssfWorkbook.getNumberOfSheets(); numSheet++) {
HSSFSheet hssfSheet = hssfWorkbook.getSheetAt(numSheet);
if (hssfSheet == null) {
continue;
}
// 循环行Row
for (int rowNum = 1; rowNum <= hssfSheet.getLastRowNum(); rowNum++) {
HSSFRow hssfRow = hssfSheet.getRow(rowNum);
if (hssfRow == null) {
continue;
}
exam = new ExamInfo();
// 循环列Cell 准考证号
HSSFCell admission_number = hssfRow.getCell(0);
if (admission_number == null) {
continue;
}
exam.setAdmission_number(getValue(admission_number));
//读取SFZ号
HSSFCell userCard= hssfRow.getCell(2);
if (userCard == null) {
continue;
}
exam.setUserCard(getValue(userCard));
//读取座位号
HSSFCell seat_number = hssfRow.getCell(3);
if (seat_number == null) {
continue;
}
exam.setSeat_number(getValue(seat_number));
//读取考场号
HSSFCell fRoomName = hssfRow.getCell(6);
if (fRoomName == null) {
continue;
}
exam.setfRoomName(getValue(fRoomName));
//读取开考时间
HSSFCell fBeginTime = hssfRow.getCell(8);
if (fBeginTime == null) {
continue;
}
exam.setfBeginTime(getValue(fBeginTime));
//读取结束时间
HSSFCell fEndTime = hssfRow.getCell(9);
if (fEndTime == null) {
continue;
}
exam.setfEndTime(getValue(fEndTime));
list.add(exam);
}
}
return list;
}
/**
* 得到Excel表中的值
*
* @param hssfCell
* Excel中的每一个格子
* @return Excel中每一个格子中的值
*/
private static String getValue(HSSFCell hssfCell) {
if (hssfCell.getCellType() == HSSFCell.CELL_TYPE_BOOLEAN) {
// 返回布尔类型的值
return String.valueOf(hssfCell.getBooleanCellValue());
} else if (hssfCell.getCellType() == HSSFCell.CELL_TYPE_NUMERIC) {
// 返回数值类型的值
DecimalFormat df = new DecimalFormat("0");
String strCell = df.format(hssfCell.getNumericCellValue());
return String.valueOf(strCell);
} else {
// 返回字符串类型的值
return String.valueOf(hssfCell.getStringCellValue());
}
}
}
当然有导入功能，一定也有导出功能，下面介绍导出功能，直接上代码：
import java.io.OutputStream;
import java.util.List;
import javax.servlet.http.HttpServletResponse;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFRichTextString;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import com.forenms.exam.domain.ExamInfo;
public class ObjectToExcellUtil {
//导出的文件名称
public static String FILE_NAME = "examInfo";
public static String[] CELLS = {"序号","编号","真实姓名","证件类型","证件号","性别","出生年月","科目","准考证号","座位号","考场号","开考时间","结束时间"};
//examId,realName,SFZ,user_card,sex,没有字段,assessment_project,admission_number,seat_number
public static void examInfoToExcel(List<ExamInfo> xls,int CountColumnNum,String filename,String[] names,HttpServletResponse response) throws Exception {
// 获取总列数
// int CountColumnNum = CountColumnNum;
// 创建Excel文档
HSSFWorkbook hwb = new HSSFWorkbook();
ExamInfo xlsDto = null;
// sheet 对应一个工作页
HSSFSheet sheet = hwb.createSheet(filename);
// sheet.setColumnHidden(1,true);//隐藏列
HSSFRow firstrow = sheet.createRow(0); // 下标为0的行开始
HSSFCell[] firstcell = new HSSFCell[names.length];
for (int j = 0; j < names.length; j++) {
sheet.setColumnWidth(j, 5000);
firstcell[j] = firstrow.createCell(j);
firstcell[j].setCellValue(new HSSFRichTextString(names[j]));
}
for (int i = 0; i < CountColumnNum; i++) {
// 创建一行
HSSFRow row = sheet.createRow(i + 1);
// 得到要插入的每一条记录
xlsDto = xls.get(i);
for (int colu = 0; colu <= 12; colu++) {
// 在一行内循环
HSSFCell xh = row.createCell(0);
xh.setCellValue(i+1);
HSSFCell examid = row.createCell(1);
examid.setCellValue(xlsDto.getExamId());
HSSFCell realName = row.createCell(2);
realName.setCellValue(xlsDto.getRealName());
HSSFCell zjlx = row.createCell(3);
zjlx.setCellValue("SFZ");
HSSFCell userCard = row.createCell(4);
userCard.setCellValue(xlsDto.getUserCard());
HSSFCell sex = row.createCell(5);
sex.setCellValue(xlsDto.getSex());
HSSFCell born = row.createCell(6);
String bornTime = xlsDto.getUserCard().substring(6, 14);
born.setCellValue(bornTime);
HSSFCell assessment_project = row.createCell(7);
assessment_project.setCellValue(xlsDto.getAssessmentProject());
HSSFCell admission_number = row.createCell(8);
admission_number.setCellValue(xlsDto.getAdmission_number());
HSSFCell seat_number = row.createCell(9);
seat_number.setCellValue(xlsDto.getSeat_number());
HSSFCell fRoomName = row.createCell(10);
fRoomName.setCellValue(xlsDto.getfRoomName());
HSSFCell fBeginTime = row.createCell(11);
fBeginTime.setCellValue(xlsDto.getfBeginTime());
HSSFCell fEndTime = row.createCell(12);
fEndTime.setCellValue(xlsDto.getfEndTime());
}
}
// 创建文件输出流，准备输出电子表格
response.reset();
response.setContentType("application/vnd.ms-excel;charset=GBK");
response.addHeader("Content-Disposition", "attachment;filename="+filename+".xls");
OutputStream os = response.getOutputStream();
hwb.write(os);
os.close();
}
}
导出的功能十分简单，只要封装好对象，直接调用方法即可，现在讲讲导入的时候前台页面怎么调用问题，
<form method="post" action="adminLogin/auditResults/import" enctype="multipart/form-data" onsubmit="return importData();"> <input id="filepath" name="insuranceExcelFile" type="file" size="30" value="" style="font-size:14px" /> <button type="submit" style="height:25px" value="导入数据">导入数据</button>
导入的前台表单提交的时候，要注意设置 enctype=”multipart/form-data” ，其他也没什么难度。
后台接受的controller：
/**
* 读取用户提供的examinfo.xls
* @param request
* @param response
* @param session
* @return
* @throws Exception
*/
@RequestMapping(value="adminLogin/auditResults/import",method=RequestMethod.POST)
public ModelAndView importExamInfoExcell(HttpServletRequest request,HttpServletResponse response, HttpSession session)throws Exception{
//获取请求封装
MultipartHttpServletRequest multipartRequest=(MultipartHttpServletRequest)request;
Map<String, MultipartFile> fileMap = multipartRequest.getFileMap();
//读取需要填写准考证号的人员名单
ExamInfo examInfo = new ExamInfo();
List<ExamInfo> info = examInfoService.queryExamInfoForDownLoad(examInfo);
//获取请求封装对象
for(Entry<String, MultipartFile> entry: fileMap.entrySet()){
MultipartFile multipartFile = entry.getValue();
InputStream inputStream = multipartFile.getInputStream();
POIFSFileSystem poifsFileSystem = new POIFSFileSystem(inputStream);
//从xml读取需要的数据
List<ExamInfo> list = ExcellToObjectUtil.readXlsForJS(poifsFileSystem);
for (ExamInfo ei : list) {
//通过匹配SFZ号 填写对应的数据
for (ExamInfo in : info){
//如果SFZ号 相同 则录入数据
if(in.getUserCard().trim().toUpperCase().equals(ei.getUserCard().trim().toUpperCase())){
ei.setExamId(in.getExamId());
examInfoService.updateExamInfoById(ei);
break;
}
}
}
}
ModelAndView mav=new ModelAndView(PATH+"importExcelTip");
request.setAttribute("data", "ok");
return mav;
}
好了，Excel导入导出的功能都搞定了，简单吧，需求自己修改一下 封装的对象格式和设置Excel的每个列即可自己使用！！
希望本文所述对大家java程序设计有所帮助。
