POI read/export Excel file
1. Import the jar package
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.17</version>
</dependency>
2. Read Excel
package service;
import org.apache.poi.ss.usermodel.CellType;
import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.LinkedHashMap;
import java.util.Map;
/**
* @author cxt
* @date 2020/7/21
* 读取Excel文件中的值
*/
public class DataService {
public static void main(String[] args) throws IOException {
redExcel("E:\\aa.xslx");
}
/**
* 读取excel内容
* <p>
* 用户模式下：
* 弊端：对于少量的数据可以，单数对于大量的数据，会造成内存占据过大，有时候会造成内存溢出
* 建议修改成事件模式
*/
public static void redExcel(String filePath) throws IOException {
//读取本地文件
//InputStream inputStream = new FileInputStream("E:\\aa.xslx");
//读取导入文件
File file = new File(filePath);
if (!file.exists()){
throw new Exception("文件不存在!");
}
InputStream in = new FileInputStream(file);
// 读取整个Excel
XSSFWorkbook sheets = new XSSFWorkbook(in);
// 获取第一个表单Sheet
XSSFSheet sheetAt = sheets.getSheetAt(0);
// 获取第一行为标题行
XSSFRow titleRow = sheetAt.getRow(0);
// 循环读取某一行
for (Row row : sheetAt) {
// 读取每一行的单元格
if (index == 0) {
index++;
continue;
}
//获取列长度
int ofCells = row.getPhysicalNumberOfCells();
//获取行长度
int ofRows = row.getPhysicalNumberOfRows();
for (int j = 0; j < row.getLastCellNum(); j++) {
//单元格处理
HSSFCell cell = row.getCell(j);
String cellStr = "";
if (cell == null) {
// 单元格为空设置cellStr为空串
cellStr = "";
} else if (cell.getCellType() == HSSFCell.CELL_TYPE_BOOLEAN) {
// 对布尔值的处理
cellStr = String.valueOf(cell.getBooleanCellValue());
} else if (cell.getCellType() == HSSFCell.CELL_TYPE_NUMERIC) {
// 对数字值的处理
cellStr = cell.getNumericCellValue() + "";
} else {
// 其余按照字符串处理
cellStr = cell.getStringCellValue();
}
//将Excel表中单元格的值与数据库表值的对应
if (j == 0) {
String stringCellValue1 = cellStr;
}
if (j == 1) {
String stringCellValue2 = cellStr;
}
if (j == 2) {
String stringCellValue3 = cellStr;
}
if (j == 3) {
String stringCellValue4 = cellStr;
}
//------保存入数据库------
}
}
}
3. Read the result
Original Excel table content:
4. Export Excel
public String export(HttpServletResponse response) {
String fileName = "xxx记录";
List<TpPatrolModel> excelList = tpPatrolModelService.selectTpPatrolModelList(new TpPatrolModel());
try {
response.setContentType("application/vnd.ms-excel");
response.setCharacterEncoding("utf-8");
fileName = URLEncoder.encode(fileName, "UTF-8");
response.setHeader("Content-disposition", "attachment;filename=" + fileName + ".xlsx");
EasyExcel.write(response.getOutputStream(), TpPatrolModel.class).sheet(1).doWrite(excelList);
} catch (IOException e) {
e.printStackTrace();
return e.getMessage();
}
return "操作成功";
}
public ApiRest export2(@RequestBody String examId) {
StringBuffer stringBuffer = new StringBuffer("");
char s = '=';
for (int i = 0; i < examId.length(); i++) {
if (examId.charAt(i) != s) {
stringBuffer.append(examId.charAt(i));
}
}
examId = stringBuffer.toString();
List<UserExam> list1 = baseService.selectAllByExamId(examId);
//创建工作薄
HSSFWorkbook workbook=new HSSFWorkbook();
//创建sheet
HSSFSheet sheet=workbook.createSheet();
//创建第一行row
HSSFRow header=sheet.createRow(0);
//创建单元格并插入表头
HSSFCell cell=null;
String[] infos={
"序号","考生姓名","考生身份证号","所属单位","考试得分"};
for(int i=0;i<infos.length;i++){
cell=header.createCell(i);
cell.setCellValue(infos[i]);
}
//
HSSFRow body=null;
for(int i=1;i<=list1.size();i++){
UserExam fee = list1.get(i-1);
String realName = sysUserService.selectRealName(fee.getUserId());
String userName = sysUserService.selectUserName(fee.getUserId());
String dw = sysUserService.selectDw(fee.getUserId());
body=sheet.createRow(i);
cell=body.createCell(0);
cell.setCellValue(i);
cell=body.createCell(1);
cell.setCellValue(realName);
cell=body.createCell(2);
cell.setCellValue(userName);
cell=body.createCell(3);
cell.setCellValue(dw);
cell=body.createCell(4);
cell.setCellValue(fee.getMaxScore());
System.out.println(realName + userName + dw);
}
//创建文件
String filePath = new String("src/main/resources/" + "文件名称.xls");
File file=new File(filePath);
try {
file.createNewFile();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
//文件输出流
try {
FileOutputStream stream= FileUtils.openOutputStream(file);
//写入
workbook.write(stream);
//关闭输出流
stream.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return super.success("成功",filePath);
}
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