1.pom.xml导入maven依赖
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.8</version>
</dependency>2.html 通过window.location.href来访问接口，直接弹出下载框
<button class="btn btn-success" onclick="exportExcel();return false;">导出Excel</button><script>
function exportExcel(){
window.location.href = "/sys/user/exportExcel";
}
</script>3.后端控制器controller获取response中的OutStream 流 ，将excel文件写入到流
@GetMapping("/exportExcel")
public void exportExcel(HttpServletRequest request,HttpServletResponse response) throws RowsExceededException, WriteException, IOException{
List<UserDO> grouppList = userService.selectAllUser();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyyMMdd");
String dateFormat = simpleDateFormat.format(new Date());
String path=dateFormat+"用户信息.xls";
//设置表格标题行
String[] headers = new String[] {"序号","ID","姓名","用户名","邮箱","时间","分数","省","市","区"};
List<Object[]> dataList = new ArrayList<Object[]>();
Object[] objs = null;
for (int i = 0; i < grouppList.size(); i++) {
objs = new Object[headers.length];
objs[0] = 0;//设置序号,在工具类中会出现
objs[1] = grouppList.get(i).getUId();
objs[2] = grouppList.get(i).getName();
objs[3] = grouppList.get(i).getNickname();
objs[4] = grouppList.get(i).getEmail();
objs[5] = grouppList.get(i).getBindDate();
objs[6] = grouppList.get(i).getScore();
objs[7] = grouppList.get(i).getProvinces();
objs[8] = grouppList.get(i).getMunicipalities();
objs[9] = grouppList.get(i).getDistricts();
dataList.add(objs);//数据添加到excel表格
}
//使用流将数据导出
OutputStream out = null;
try {
//防止中文乱码
String headStr = "attachment; filename=\"" + new String(path.getBytes("gb2312"), "ISO8859-1" ) + "\"";
response.setContentType("octets/stream");
response.setContentType("APPLICATION/OCTET-STREAM");
response.setHeader("Content-Disposition", headStr);
out = response.getOutputStream();
ExportExcelSeedBack ex = new ExportExcelSeedBack(path, headers, dataList);//没有标题
ex.export(out);
out.flush();
out.close();
} catch (Exception e) {
e.printStackTrace();
}
}4.工具类
package com.basksingle.system.controller;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import javax.servlet.http.HttpServletResponse;
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFFont;
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 org.apache.poi.hssf.util.HSSFColor;
public class ExportExcelSeedBack {
//显示的导出表的标题
private String title;
//导出表的列名
private String[] rowName ;
private List<Object[]> dataList = new ArrayList<Object[]>();
HttpServletResponse response;
//构造方法，传入要导出的数据
public ExportExcelSeedBack(String title,String[] rowName,List<Object[]> dataList){
this.dataList = dataList;
this.rowName = rowName;
this.title = title;
}
/*
* 导出数据
* */
public void export(OutputStream out) throws Exception{
try{
HSSFWorkbook workbook = new HSSFWorkbook(); // 创建工作簿对象
HSSFSheet sheet = workbook.createSheet(title); // 创建工作表
// 产生表格标题行
// HSSFRow rowm = sheet.createRow(0);
// HSSFCell cellTiltle = rowm.createCell(0);
//sheet样式定义【getColumnTopStyle()/getStyle()均为自定义方法 - 在下面 - 可扩展】
HSSFCellStyle columnTopStyle = this.getColumnTopStyle(workbook);//获取列头样式对象
HSSFCellStyle style = this.getStyle(workbook); //单元格样式对象
// sheet.addMergedRegion(new CellRangeAddress(0, 1, 0, (rowName.length-1)));//合并单元格
// cellTiltle.setCellStyle(columnTopStyle);
// cellTiltle.setCellValue(title);
// 定义所需列数
int columnNum = rowName.length;
HSSFRow rowRowName = sheet.createRow(0); // 在索引2的位置创建行(最顶端的行开始的第二行)
// 将列头设置到sheet的单元格中
for(int n=0;n<columnNum;n++){
HSSFCell cellRowName = rowRowName.createCell(n); //创建列头对应个数的单元格
cellRowName.setCellType(HSSFCell.CELL_TYPE_STRING); //设置列头单元格的数据类型
HSSFRichTextString text = new HSSFRichTextString(rowName[n]);
cellRowName.setCellValue(text); //设置列头单元格的值
cellRowName.setCellStyle(columnTopStyle); //设置列头单元格样式
}
//将查询出的数据设置到sheet对应的单元格中
for(int i=0;i<dataList.size();i++){
Object[] obj = dataList.get(i);//遍历每个对象
HSSFRow row = sheet.createRow(i+1);//创建所需的行数（从第二行开始写数据）
for(int j=0; j<obj.length; j++){
HSSFCell cell = null; //设置单元格的数据类型
if(j == 0){
cell = row.createCell(j,HSSFCell.CELL_TYPE_NUMERIC);
cell.setCellValue(i+1);
}else{
cell = row.createCell(j,HSSFCell.CELL_TYPE_STRING);
if(!"".equals(obj[j]) && obj[j] != null){
cell.setCellValue(obj[j].toString()); //设置单元格的值
}
}
cell.setCellStyle(style); //设置单元格样式
}
}
//让列宽随着导出的列长自动适应
for (int colNum = 0; colNum < columnNum; colNum++) {
int columnWidth = sheet.getColumnWidth(colNum) / 256;
for (int rowNum = 0; rowNum < sheet.getLastRowNum(); rowNum++) {
HSSFRow currentRow;
//当前行未被使用过
if (sheet.getRow(rowNum) == null) {
currentRow = sheet.createRow(rowNum);
} else {
currentRow = sheet.getRow(rowNum);
}
// if (currentRow.getCell(colNum) != null) {
// HSSFCell currentCell = currentRow.getCell(colNum);
// if (currentCell.getCellType() == HSSFCell.CELL_TYPE_STRING) {
// int length = currentCell.getStringCellValue().getBytes().length;
// if (columnWidth < length) {
// columnWidth = length;
// }
// }
// }
if (currentRow.getCell(colNum) != null) {
HSSFCell currentCell = currentRow.getCell(colNum);
if (currentCell.getCellType() == HSSFCell.CELL_TYPE_STRING) {
int length = 0;
try {
length = currentCell.getStringCellValue().getBytes().length;
} catch (Exception e) {
//e.printStackTrace();
}
if (columnWidth < length) {
columnWidth = length;
}
}
}
}
if(colNum == 0){
sheet.setColumnWidth(colNum, (columnWidth-2) * 256);
}else{
sheet.setColumnWidth(colNum, (columnWidth+4) * 256);
}
}
if(workbook !=null){
try{
workbook.write(out);
}catch (IOException e) {
e.printStackTrace();
}
}
}catch(Exception e){
e.printStackTrace();
}
finally{
out.close();
}
}
/*
* 列头单元格样式
*/
public HSSFCellStyle getColumnTopStyle(HSSFWorkbook workbook) {
// 设置字体
HSSFFont font = workbook.createFont();
//设置字体大小
font.setFontHeightInPoints((short)11);
//字体加粗
font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
//设置字体名字
font.setFontName("Courier New");
//设置样式;
HSSFCellStyle style = workbook.createCellStyle();
//设置底边框;
style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
//设置底边框颜色;
style.setBottomBorderColor(HSSFColor.BLACK.index);
//设置左边框;
style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
//设置左边框颜色;
style.setLeftBorderColor(HSSFColor.BLACK.index);
//设置右边框;
style.setBorderRight(HSSFCellStyle.BORDER_THIN);
//设置右边框颜色;
style.setRightBorderColor(HSSFColor.BLACK.index);
//设置顶边框;
style.setBorderTop(HSSFCellStyle.BORDER_THIN);
//设置顶边框颜色;
style.setTopBorderColor(HSSFColor.BLACK.index);
//在样式用应用设置的字体;
style.setFont(font);
//设置自动换行;
style.setWrapText(false);
//设置水平对齐的样式为居中对齐;
style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
//设置垂直对齐的样式为居中对齐;
style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
return style;
}
/*
* 列数据信息单元格样式
*/
public HSSFCellStyle getStyle(HSSFWorkbook workbook) {
// 设置字体
HSSFFont font = workbook.createFont();
//设置字体大小
//font.setFontHeightInPoints((short)10);
//字体加粗
//font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);
//设置字体名字
font.setFontName("Courier New");
//设置样式;
HSSFCellStyle style = workbook.createCellStyle();
//设置底边框;
style.setBorderBottom(HSSFCellStyle.BORDER_THIN);
//设置底边框颜色;
style.setBottomBorderColor(HSSFColor.BLACK.index);
//设置左边框;
style.setBorderLeft(HSSFCellStyle.BORDER_THIN);
//设置左边框颜色;
style.setLeftBorderColor(HSSFColor.BLACK.index);
//设置右边框;
style.setBorderRight(HSSFCellStyle.BORDER_THIN);
//设置右边框颜色;
style.setRightBorderColor(HSSFColor.BLACK.index);
//设置顶边框;
style.setBorderTop(HSSFCellStyle.BORDER_THIN);
//设置顶边框颜色;
style.setTopBorderColor(HSSFColor.BLACK.index);
//在样式用应用设置的字体;
style.setFont(font);
//设置自动换行;
style.setWrapText(false);
//设置水平对齐的样式为居中对齐;
style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
//设置垂直对齐的样式为居中对齐;
style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);
return style;
}
}
原博客：https://blog.csdn.net/qq_38423105/article/details/80782283