一、引入poi

<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.6</version>
</dependency>
二、创建工具类
import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import java.util.List;
import java.util.Map;
public class ExcelUtil {
/**
* 导出Excel
*
* @param sheetName sheet名称
* @param title 标题
* @param list 内容
* @param wb HSSFWorkbook对象
* @return
*/
public static HSSFWorkbook getHSSFWorkbook(String sheetName, String[] title, String[] rows,  List<Map<String, String>> list, HSSFWorkbook wb) {
// 第一步，创建一个HSSFWorkbook，对应一个Excel文件
if (wb == null) {
wb = new HSSFWorkbook();
}
// 第二步，在workbook中添加一个sheet,对应Excel文件中的sheet
HSSFSheet sheet = wb.createSheet(sheetName);
// 第三步，在sheet中添加表头第0行,注意老版本poi对Excel的行数列数有限制
HSSFRow row = sheet.createRow(0);
// 第四步，创建单元格，并设置值表头 设置表头居中
HSSFCellStyle style = wb.createCellStyle();
style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 创建一个居中格式
//声明列对象
HSSFCell cell = null;
//创建标题
for (int i = 0; i < title.length; i++) {
cell = row.createCell(i);
cell.setCellValue(title[i]);
cell.setCellStyle(style);
}
//创建内容
for (int i = 0; i < list.size(); i++) {
row = sheet.createRow(i + 1);
Map<String, String> map = list.get(i);
for (int j = 0; j < title.length; j++) {
//将内容按顺序赋给对应的列对象
row.createCell(j).setCellValue(map.get(rows[j]));
}
}
return wb;
}
}
三、演示
@GetMapping("/excel")
public void excel(HttpServletRequest request, HttpServletResponse response) {
//获取数据
List<Map<String, String>> list = new ArrayList<Map<String, String>>();
for (int i = 0; i < 10; i++) {
Map<String, String> map = new HashMap<String, String>();
map.put("name", "姓名" + i);
map.put("sex", "性别" + i);
map.put("age", "年龄" + i);
map.put("school", "学校" + i);
map.put("class", "班级" + i);
list.add(map);
}
//excel标题
String[] title = {"名称", "性别", "年龄", "学校", "班级"};
//行记录
String[] rows = {"name", "sex", "age", "school", "class"};
//excel文件名
String fileName = "学生信息表" + System.currentTimeMillis() + ".xls";
String sheetName = "学生信息表";
HSSFWorkbook wb = ExcelUtil.getHSSFWorkbook(sheetName, title, rows, list, null);
try {
this.setResponseHeader(response, fileName);
OutputStream os = response.getOutputStream();
wb.write(os);
os.flush();
os.close();
} catch (Exception e) {
e.printStackTrace();
}
}
//发送响应流方法
public void setResponseHeader(HttpServletResponse response, String fileName) {
try {
try {
fileName = new String(fileName.getBytes(), "ISO8859-1");
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
response.setContentType("application/octet-stream;charset=ISO8859-1");
response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
response.addHeader("Pargam", "no-cache");
response.addHeader("Cache-Control", "no-cache");
} catch (Exception ex) {
ex.printStackTrace();
}
}