注意：本文用到了java8新特性，要jdk1.8以上
1.导入poi 依赖
<!-- poi导入导出 -->
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.13</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.13</version>
</dependency>
2.添加ExcelUtils工具类
package com.iflytek.edu.hnezzhxy.util;
import com.iflytek.edu.hnezzhxy.common.config.Constants;
import com.iflytek.edu.hnezzhxy.common.config.ExcelColumn;
import org.apache.poi.hssf.usermodel.HSSFDateUtil;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.ss.usermodel.*;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.MediaType;
import org.springframework.util.CollectionUtils;
import org.springframework.web.multipart.MultipartFile;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.math.BigDecimal;
import java.net.URLEncoder;
import java.util.*;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* @version 1.0
* @description 导入Execel
* @create 2020/06/24 16:09
*/
public class ExcelUtils {
private final static Logger log = LoggerFactory.getLogger(ExcelUtils.class);
public static <T> List<T> readExcel(String path, Class<T> cls, MultipartFile file){
String fileName = file.getOriginalFilename();
if (!fileName.matches("^.+\\.(?i)(xls)$") && !fileName.matches("^.+\\.(?i)(xlsx)$")) {
log.error("上传文件格式不正确");
}
List<T> dataList = new ArrayList<>();
Workbook workbook = null;
try {
InputStream is = file.getInputStream();
if (fileName.endsWith(Constants.EXCEL2007)) {
workbook = new XSSFWorkbook(is);
}
if (fileName.endsWith(Constants.EXCEL2003)) {
workbook = new HSSFWorkbook(is);
}
if (workbook != null) {
//类映射 注解 value-->bean columns
Map<String, List<Field>> classMap = new HashMap<>();
List<Field> fields = Stream.of(cls.getDeclaredFields()).collect(Collectors.toList());
fields.forEach(
field -> {
ExcelColumn annotation = field.getAnnotation(ExcelColumn.class);
if (annotation != null) {
String value = annotation.value();
if (StringUtils.isBlank(value)) {
return;//return起到的作用和continue是相同的 语法
}
if (!classMap.containsKey(value)) {
classMap.put(value, new ArrayList<>());
}
field.setAccessible(true);
classMap.get(value).add(field);
}
}
);
//索引-->columns
Map<Integer, List<Field>> reflectionMap = new HashMap<>(16);
//默认读取第一个sheet
Sheet sheet = workbook.getSheetAt(0);
boolean firstRow = true;
for (int i = sheet.getFirstRowNum(); i <= sheet.getLastRowNum(); i++) {
Row row = sheet.getRow(i);
//首行 提取注解
if (firstRow) {
for (int j = row.getFirstCellNum(); j <= row.getLastCellNum(); j++) {
Cell cell = row.getCell(j);
String cellValue = getCellValue(cell);
if (classMap.containsKey(cellValue)) {
reflectionMap.put(j, classMap.get(cellValue));
}
}
firstRow = false;
} else {
//忽略空白行
if (row == null) {
continue;
}
try {
T t = cls.newInstance();
//判断是否为空白行
boolean allBlank = true;
for (int j = row.getFirstCellNum(); j <= row.getLastCellNum(); j++) {
if (reflectionMap.containsKey(j)) {
Cell cell = row.getCell(j);
String cellValue = getCellValue(cell);
if (StringUtils.isNotBlank(cellValue)) {
allBlank = false;
}
List<Field> fieldList = reflectionMap.get(j);
fieldList.forEach(
x -> {
try {
handleField(t, cellValue, x);
} catch (Exception e) {
log.error(String.format("第:%row行 field:%s value:%s exception!", x.getName(), cellValue), e);
}
}
);
}
}
if (!allBlank) {
dataList.add(t);
} else {
log.warn(String.format("row:%s is blank ignore!", i));
}
} catch (Exception e) {
log.error(String.format("parse row:%s exception!", i), e);
}
}
}
}
} catch (Exception e) {
log.error(String.format("parse excel exception!"), e);
} finally {
if (workbook != null) {
try {
workbook.close();
} catch (Exception e) {
log.error(String.format("parse excel exception!"), e);
}
}
}
return dataList;
}
private static <T> void handleField(T t, String value, Field field) throws Exception {
Class<?> type = field.getType();
if (type == null || type == void.class || StringUtils.isBlank(value)) {
return;
}
if (type == Object.class) {
field.set(t, value);
//数字类型
} else if (type.getSuperclass() == null || type.getSuperclass() == Number.class) {
if (type == int.class || type == Integer.class) {
field.set(t, Integer.parseInt(value));
} else if (type == long.class || type == Long.class) {
field.set(t, Long.parseLong(value));
} else if (type == byte.class || type == Byte.class) {
field.set(t, Byte.parseByte(value));
} else if (type == short.class || type == Short.class) {
field.set(t, Short.parseShort(value));
} else if (type == double.class || type == Double.class) {
field.set(t, Double.parseDouble(value));
} else if (type == float.class || type == Float.class) {
field.set(t, Float.parseFloat(value));
} else if (type == char.class || type == Character.class) {
field.set(t, String.valueOf(value));
} else if (type == boolean.class) {
field.set(t, Boolean.valueOf(value));
} else if (type == BigDecimal.class) {
field.set(t, new BigDecimal(value));
}
} else if (type == Boolean.class) {
field.set(t, Boolean.valueOf(value));
} else if (type == Date.class) {
//
field.set(t, value);
} else if (type == String.class) {
field.set(t, value);
} else {
Constructor<?> constructor = type.getConstructor(String.class);
field.set(t, constructor.newInstance(value));
}
}
private static String getCellValue(Cell cell) {
if (cell == null) {
return "";
}
if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) {
if (HSSFDateUtil.isCellDateFormatted(cell)) {
return HSSFDateUtil.getJavaDate(cell.getNumericCellValue()).toString();
} else {
return new BigDecimal(cell.getNumericCellValue()).toString();
}
} else if (cell.getCellType() == Cell.CELL_TYPE_STRING) {
return StringUtils.trimToEmpty(cell.getStringCellValue());
} else if (cell.getCellType() == Cell.CELL_TYPE_FORMULA) {
return StringUtils.trimToEmpty(cell.getCellFormula());
} else if (cell.getCellType() == Cell.CELL_TYPE_BLANK) {
return "";
} else if (cell.getCellType() == Cell.CELL_TYPE_BOOLEAN) {
return String.valueOf(cell.getBooleanCellValue());
} else if (cell.getCellType() == Cell.CELL_TYPE_ERROR) {
return "ERROR";
} else {
return cell.toString().trim();
}
}
public static <T> void writeExcel(HttpServletResponse response, List<T> dataList, Class<T> cls) {
Field[] fields = cls.getDeclaredFields();
List<Field> fieldList = Arrays.stream(fields)
.filter(field -> {
//ExcelColumn.class注解的字段必须中测value值要和excel中的表头文字要保持一模一样，不然不能将excel读取的内容存到相对应的字段上
ExcelColumn annotation = field.getAnnotation(ExcelColumn.class);
if (annotation != null && annotation.col() > 0) {
field.setAccessible(true);
return true;
}
return false;
}).sorted(Comparator.comparing(field -> {
int col = 0;
ExcelColumn annotation = field.getAnnotation(ExcelColumn.class);
if (annotation != null) {
col = annotation.col();
}
return col;
})).collect(Collectors.toList());
Workbook wb = new XSSFWorkbook();
Sheet sheet = wb.createSheet("Sheet1");
AtomicInteger ai = new AtomicInteger();
{
Row row = sheet.createRow(ai.getAndIncrement());
AtomicInteger aj = new AtomicInteger();
//写入头部
fieldList.forEach(field -> {
ExcelColumn annotation = field.getAnnotation(ExcelColumn.class);
String columnName = "";
if (annotation != null) {
columnName = annotation.value();
}
Cell cell = row.createCell(aj.getAndIncrement());
CellStyle cellStyle = wb.createCellStyle();
cellStyle.setFillForegroundColor(IndexedColors.WHITE.getIndex());
cellStyle.setFillPattern(CellStyle.SOLID_FOREGROUND);
cellStyle.setAlignment(CellStyle.ALIGN_CENTER);
Font font = wb.createFont();
font.setBoldweight(Font.BOLDWEIGHT_NORMAL);
cellStyle.setFont(font);
cell.setCellStyle(cellStyle);
cell.setCellValue(columnName);
});
}
if (!CollectionUtils.isEmpty(dataList)) {
dataList.forEach(t -> {
Row row1 = sheet.createRow(ai.getAndIncrement());
AtomicInteger aj = new AtomicInteger();
fieldList.forEach(field -> {
Class<?> type = field.getType();
Object value = "";
try {
value = field.get(t);
} catch (Exception e) {
e.printStackTrace();
}
Cell cell = row1.createCell(aj.getAndIncrement());
if (value != null) {
if (type == Date.class) {
cell.setCellValue(value.toString());
} else {
cell.setCellValue(value.toString());
}
cell.setCellValue(value.toString());
}
});
});
}
//冻结窗格
wb.getSheet("Sheet1").createFreezePane(0, 1, 0, 1);
//浏览器下载excel
buildExcelDocument("abbot.xlsx", wb, response);
//生成excel文件
// buildExcelFile(".\\default.xlsx",wb);
}
/**
* 浏览器下载excel
* @param fileName
* @param wb
* @param response
*/
private static void buildExcelDocument(String fileName, Workbook wb, HttpServletResponse response){
try {
response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
response.setHeader("Content-Disposition", "attachment;filename="+ URLEncoder.encode(fileName, "utf-8"));
response.flushBuffer();
wb.write(response.getOutputStream());
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 生成excel文件
* @param path 生成excel路径
* @param wb
*/
private static void buildExcelFile(String path, Workbook wb){
File file = new File(path);
if (file.exists()) {
file.delete();
}
try {
wb.write(new FileOutputStream(file));
} catch (Exception e) {
e.printStackTrace();
}
}
}
3.控制类代码
package com.iflytek.edu.hnezzhxy.controller;
import com.alibaba.fastjson.JSON;
import com.iflytek.edu.hnezzhxy.model.ExcelZsbmStudentResultImport;
import com.iflytek.edu.hnezzhxy.service.ImportExcelService;
import com.iflytek.edu.hnezzhxy.util.ExcelUtils;
import com.iflytek.edu.hnezzhxy.vo.ResultVO;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;
import java.util.List;
/**
* @version 1.0
* @description
* @create 2020/06/24 15:54
*/
@RestController
@RequestMapping("/excel")
public class ImportExcelController {
@Autowired
private ImportExcelService importExcelService;
/**
* 导入座位号
* @param file excel文件
*/
@RequestMapping(value = "/readExcel", method = RequestMethod.POST)
public void readExcel(@RequestParam(value="uploadFile", required = false) MultipartFile file){
long t1 = System.currentTimeMillis();
List<ExcelZsbmStudentResultImport> list = ExcelUtils.readExcel("", ExcelZsbmStudentResultImport.class, file);
long t2 = System.currentTimeMillis();
System.out.println(String.format("read over! cost:%sms", (t2 - t1)));
list.forEach(
b -> System.out.println(JSON.toJSONString(b))
);
}
}
4.自定义导入excel的字段的注解
package com.iflytek.edu.hnezzhxy.common.config;
import java.lang.annotation.*;
@Target({ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ExcelColumn {
/**
* Excel标题
*
* @return
* @author Lynch
*/
String value() default "";
/**
* Excel从左往右排列位置
*
* @return
* @author Lynch
*/
int col() default 0;
/**
* 字典表
* @return
* @author Lynch
*/
String dicTable() default "";
/**
* 字典编码
* @return
* @author Lynch
*/
String dicCode() default "";
/**
* 字典名称
* @return
* @author Lynch
*/
String dicName() default "";
}
5.定义要导入的字段模型
package com.iflytek.edu.hnezzhxy.model;
import com.iflytek.edu.hnezzhxy.common.config.ExcelColumn;
import lombok.Data;
/**
* @version 1.0
* @description
* @create 2020/06/24 17:30
*/
@Data
public class ExcelZsbmStudentResultImport {
@ExcelColumn(value = "学生id", col = 1)
private String sid;
@ExcelColumn(value = "考场号", col = 2)
private String examinationRoomNum;
@ExcelColumn(value = "座位号", col = 3)
private String num;
@ExcelColumn(value = "考试成绩", col = 4)
private Double score;
}
6.准备的excel
7.postman导入测试
8.控制台打印
然后执行insert方法就可以导入数据库了
9.对比传统的excel导入的优缺点：
1.优点:自定义注解导入比较通用，其他模块也需要导入功能，只需要重新定义一个导入excel的字段模型就好了
2.缺点:excel填写错误时，用户提示不太友好，因为可以通用,所以不太好控制每个模块每个字段的excel填写的错误提示