日常开发中，对于excel的导入导出的需求必不可少。在此整理一下
一、导入
1.maven导入
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.9</version>
</dependency>
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
<version>3.9</version>
</dependency>
2.添加Excel类
package com.ydwl.business.campus.common.utils;
import org.apache.poi.ss.usermodel.*;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
public class Excel {
public enum Type {
XLS(".xls"),
XLSX(".xlsx");
private String suffix;
Type(String suffix) {
this.suffix = suffix;
}
public String getSuffix() {
return suffix;
}
}
private Type type;
private Workbook workBook;
private Sheet sheet;
Excel(Workbook workBook, Type type) {
this.type = type;
this.workBook = workBook;
}
public Workbook getWorkbook() {
return workBook;
}
public String getSuffix() {
return type.getSuffix();
}
public Integer getLastRowNum() {
// get the last row number on the now select sheet
// based 0, contained n
return currentSheet().getLastRowNum();
}
public Excel createSheet() {
this.sheet = workBook.createSheet();
return this;
}
public Excel createSheet(String sheetname) {
this.sheet = workBook.createSheet(sheetname);
return this;
}
public Excel selectSheet(int index) {
this.sheet = workBook.getSheetAt(index);
return this;
}
public Excel selectSheet(String sheetname) {
this.sheet = workBook.getSheet(sheetname);
return this;
}
public Sheet currentSheet() {
if (sheet == null) {
throw new RuntimeException("Create or select sheet first.");
}
return sheet;
}
public List<?> readRow(Integer rowNum) {
Row row = currentSheet().getRow(rowNum);
if (row == null) {
return new ArrayList<>();
}
return readRow(rowNum, 0, (int) row.getLastCellNum());
}
public List<?> readRow(Integer rowNum, Integer colNum) {
// get 0 to colNum cell (not contain colNum)
return readRow(rowNum, 0, colNum);
}
public List<?> readRow(Integer rowNum, Integer firstCellNum, Integer lastCellNum) {
// get now select sheet a line, rowNum begin 0
// firstCellNum begin 0, not contain lastCellNum
List<Object> rowContent = new ArrayList<>();
Row row = currentSheet().getRow(rowNum);
for (int i = firstCellNum; i < lastCellNum; i++) {
rowContent.add(getCellValue(row.getCell(i)));
}
return rowContent;
}
public Excel writeRow(Integer rowNum, List<?> rowContent) {
int len = rowContent.size();
Row row = currentSheet().createRow(rowNum);
for (int i = 0; i < len; ++i) {
setCellValue(row.createCell(i), rowContent.get(i));
}
return this;
}
public Excel write(OutputStream out) throws IOException {
workBook.write(out);
out.flush();
return this;
}
private Object getCellValue(Cell cell) {
Object cellValue = "";
if (cell != null) {
switch (cell.getCellType()) {
case Cell.CELL_TYPE_NUMERIC:
case Cell.CELL_TYPE_FORMULA: {
if (DateUtil.isCellDateFormatted(cell)) {
cellValue = cell.getDateCellValue();
} else {
cellValue = cell.getNumericCellValue();
}
break;
}
case Cell.CELL_TYPE_BOOLEAN:
cellValue = cell.getBooleanCellValue();
break;
default:
cellValue = cell.getStringCellValue();
}
}
return cellValue;
}
private void setCellValue(Cell cell, Object value) {
if (value == null) {
cell.setCellValue("");
} else if (value instanceof String) {
cell.setCellValue((String) value);
} else if (value instanceof Number) {
cell.setCellValue(((Number) value).doubleValue());
} else if (value instanceof RichTextString) {
cell.setCellValue((RichTextString) value);
} else if (value instanceof Boolean) {
cell.setCellValue((Boolean) value);
} else {
cell.setCellValue(value.toString());
}
}
}
3.ExcelUtils类
package com.ydwl.business.campus.common.utils;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.commons.beanutils.ConvertUtils;
import org.apache.commons.collections.MapUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;
import org.springframework.util.CollectionUtils;
/**
* Excel 工具类（未优化版）
* 请了解清除大致用法之后再用，不然有坑
*
* @author Kahle
*/
public class ExcelUtils {
private static Log log = LogFactory.getLog(ExcelUtils.class);
public static final Excel.Type DEFAULT_EXCEL_TYPE = Excel.Type.XLSX;
public static Excel create() {
return create(DEFAULT_EXCEL_TYPE);
}
public static Excel create(Excel.Type excelType) {
switch (excelType) {
case XLS:
return new Excel(new HSSFWorkbook(), excelType);
case XLSX:
return new Excel(new XSSFWorkbook(), excelType);
default:
throw new RuntimeException("Excel type is error. ");
}
}
public static Excel create(InputStream in) throws IOException {
return create(DEFAULT_EXCEL_TYPE, in);
}
public static Excel create(String fileName, InputStream in) throws IOException {
String suffix = fileName.substring(
fileName.lastIndexOf('.')).toLowerCase();
for (Excel.Type type : Excel.Type.values()) {
if (type.getSuffix().equals(suffix)) {
return create(type, in);
}
}
return create(DEFAULT_EXCEL_TYPE, in);
}
public static Excel create(Excel.Type excelType, InputStream in) throws IOException {
switch (excelType) {
case XLS:
return new Excel(new HSSFWorkbook(in), excelType);
case XLSX:
return new Excel(new XSSFWorkbook(in), excelType);
default:
throw new RuntimeException("Excel type is error. ");
}
}
public static Excel createByFile(File file) throws IOException {
if (file == null || !file.exists()) {
throw new IllegalArgumentException("File is null or file not exist. ");
}
String filePath = file.toString();
String suffix = filePath.substring(
filePath.lastIndexOf('.')).toLowerCase();
InputStream in = null;
Excel result = null;
try {
in = new FileInputStream(file);
for (Excel.Type type : Excel.Type.values()) {
if (type.getSuffix().equals(suffix)) {
result = create(type, in);
}
}
} finally {
if (in != null) {
try {
in.close();
} catch (IOException e) {
log.error(e);
}
}
}
if (result != null) {
return result;
} else {
throw new RuntimeException("Suffix in file is not excel suffix. ");
}
}
public static <T> Excel createByBeans(List<T> beans) throws ReflectiveOperationException {
return createByBeans(DEFAULT_EXCEL_TYPE, beans);
}
public static <T> Excel createByBeans(Excel.Type excelType, List<T> beans) throws ReflectiveOperationException {
Excel result = create(excelType).createSheet();
if (CollectionUtils.isEmpty(beans)) {
throw new IllegalArgumentException("Beans is empty. ");
}
List<Method> usefulGetMethods = new ArrayList<>();
List<Object> rowContent = new ArrayList<>();
Class<?> clazz = beans.get(0).getClass();
Method[] methods = clazz.getMethods();
for (Method method : methods) {
String name = method.getName();
if (method.isAccessible() && name.length() > 3 &&
name.indexOf("get") == 0) {
usefulGetMethods.add(method);
name = StringUtils.uncapitalize(name.substring(3));
rowContent.add(name);
}
}
result.writeRow(0, rowContent);
for (int i = 0, len = beans.size(); i < len; i++) {
rowContent.clear();
for (Method method : usefulGetMethods) {
rowContent.add(method.invoke(beans.get(i)));
}
result.writeRow(i + 1, rowContent);
}
return result;
}
public static <T> List<T> readToBeans(Excel excel, Class<T> clazz) throws ReflectiveOperationException {
return readToBeans(excel, clazz, null);
}
public static <T> List<T> readToBeans(Excel excel, Class<T> clazz, Map<String, String> titlePropertyMap) throws ReflectiveOperationException {
boolean hasTtlPpMap = false;
if (MapUtils.isNotEmpty(titlePropertyMap)) {
hasTtlPpMap = true;
}
List<T> result = new ArrayList<>();
Integer lastRowNum = excel.getLastRowNum();
if (lastRowNum <= 0) {
throw new IllegalArgumentException("Excel not have row or not have data. ");
}
List<Method> usefulSetMethods = new ArrayList<>();
List<?> rowContent;
Method[] methods = clazz.getMethods();
rowContent = excel.readRow(0);
for (Object data : rowContent) {
String name = data + "";
if (hasTtlPpMap) {
String tmp = titlePropertyMap.get(name);
name = StringUtils.isNotBlank(tmp) ? tmp : name;
}
name = "set" + StringUtils.capitalize(name);
int size = usefulSetMethods.size();
for (Method method : methods) {
if (StringUtils.equals(method.getName(), name)) {
usefulSetMethods.add(method);
}
}
if (size + 1 != usefulSetMethods.size()) {
throw new NoSuchMethodException("Method [" + name + "] not found in class [" + clazz.getName() + "].");
}
}
for (int i = 1; i <= lastRowNum; i++) {
rowContent = excel.readRow(i);
if (CollectionUtils.isEmpty(rowContent)) {
continue;
}
T bean = clazz.newInstance();
for (int j = 0, size = rowContent.size(); j < size; j++) {
Object val = rowContent.get(j);
Class<?> valType = usefulSetMethods.get(j).getParameterTypes()[0];
if (!val.getClass().equals(valType)) {
val = ConvertUtils.convert(val, valType);
}
usefulSetMethods.get(j).invoke(bean, val);
}
result.add(bean);
}
return result;
}
public static byte[] saveToBytes(Excel excel) throws IOException {
ByteArrayOutputStream out = new ByteArrayOutputStream();
excel.write(out);
return out.toByteArray();
}
public static void saveToFile(Excel excel, File file) throws IOException {
OutputStream out = null;
try {
out = new FileOutputStream(file);
excel.write(out);
} finally {
if (out != null) {
try {
out.close();
} catch (IOException e) {
log.error(e);
}
}
}
}
}
4.使用示例
private static final Map<String, String> excelMap = new HashMap<>();
//key值即excel的表头，value为自定义对象的属性
static {
excelMap.put("学号", "no");
excelMap.put("姓名", "name");
excelMap.put("性别", "sex");
}
Excel excel = ExcelUtils.create(file.getOriginalFilename(), file.getInputStream());
excel.selectSheet(0);
List<YourObject> objectList = ExcelUtils.readToBeans(excel, YourObject.class, excelMap);
二、导出
1.maven导入
<!-- https://mvnrepository.com/artifact/com.alibaba/easyexcel -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>easyexcel</artifactId>
<version>2.1.6</version>
</dependency>
2.工具类
package com.zhangmen.kids.wechat.utils;
import com.alibaba.excel.EasyExcel;
import com.alibaba.excel.support.ExcelTypeEnum;
import com.alibaba.excel.write.metadata.style.WriteCellStyle;
import com.alibaba.excel.write.style.HorizontalCellStyleStrategy;
import org.apache.poi.ss.usermodel.HorizontalAlignment;
import javax.servlet.http.HttpServletResponse;
import java.io.OutputStream;
import java.net.URLEncoder;
import java.util.List;
public class ExcelUtil {
/**
* 导出
*
* @param response
* @param data 导出的数据
* @param fileName 文件名称
* @param sheetName sheet名称
* @param clazz 导出数据对应的类
* @throws Exception
*/
public static void writeExcel(HttpServletResponse response, List<? extends Object> data, String fileName, String sheetName, Class clazz) throws Exception {
//表头样式
WriteCellStyle headWriteCellStyle = new WriteCellStyle();
//设置表头居中对齐
headWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.CENTER);
//内容样式
WriteCellStyle contentWriteCellStyle = new WriteCellStyle();
//设置内容靠左对齐
contentWriteCellStyle.setHorizontalAlignment(HorizontalAlignment.LEFT);
HorizontalCellStyleStrategy horizontalCellStyleStrategy = new HorizontalCellStyleStrategy(headWriteCellStyle, contentWriteCellStyle);
EasyExcel.write(getOutputStream(fileName, response), clazz).excelType(ExcelTypeEnum.XLSX).sheet(sheetName).registerWriteHandler(horizontalCellStyleStrategy).doWrite(data);
}
private static OutputStream getOutputStream(String fileName, HttpServletResponse response) throws Exception {
fileName = URLEncoder.encode(fileName, "UTF-8");
response.setContentType("application/vnd.ms-excel");
response.setCharacterEncoding("utf8");
response.setHeader("Content-Disposition", "attachment;filename=" + fileName + ".xlsx");
return response.getOutputStream();
}
}
3.定义导出的对象
/**
* 资料领取详情导出excel
*/
@Data
@AllArgsConstructor
@NoArgsConstructor
@Builder
@HeadRowHeight(value = 40)
public class StudentExcelProperty{
@ExcelProperty(value = "姓名",index = 0)
@ColumnWidth(value = 15)
private String stuName;
@ExcelProperty(value = "年龄",index = 1)
@ColumnWidth(value = 20)
private String age;
@ExcelProperty(value = "性别",index = 2)
@ColumnWidth(value = 20)
private String sex;
}
4.使用示例
String fileName = "学生导出";
String sheetName = "学生导出";
List<StudentExcelProperty> excelPropertyList = new ArrayList();
try {
ExcelUtil.writeExcel(response, excelPropertyList, fileName, sheetName, LearningResourceExcelProperty.class);
} catch (Exception e) {
e.printStackTrace();
}
来源：oschina
链接：https://my.oschina.net/wuyiyi/blog/3178295