利用poi将数据库数据导出excel

@Controller
@RequestMapping("/user")
public class UserController {

@Autowired
private UserService userService;
/**
* 用于导出excel的查询结果
* @param queryJson
* @return
*/
@RequestMapping("/export")
public void export(HttpServletRequest request, HttpServletResponse response,
@RequestParam(value = "queryJson") String queryJson) {

User user = JSON.parseObject(queryJson, User.class);
List<User> userlList = userService.getUserForExcel(user);
ExportExcel<User> ee= new ExportExcel<User>();
String[] headers = { "序号", "姓名", "性别", "年龄" };
String fileName = "用户信息表";
ee.exportExcel(headers,userlList,fileName,response);
}
}

package com.jd.xe.web.service.userDevice;
import java.io.BufferedOutputStream;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;

import javax.servlet.http.HttpServletResponse;

import org.apache.poi.xssf.usermodel.XSSFCell;
import org.apache.poi.xssf.usermodel.XSSFRichTextString;
import org.apache.poi.xssf.usermodel.XSSFRow;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

import com.jd.xe.web.utils.DateUtil;

public class ExportExcel<T> {
public void exportExcel(String[] headers,Collection<T> dataset, String fileName,HttpServletResponse response) {
// 声明一个工作薄
XSSFWorkbook workbook = new XSSFWorkbook();
// 生成一个表格
XSSFSheet sheet = workbook.createSheet(fileName);
// 设置表格默认列宽度为15个字节
sheet.setDefaultColumnWidth((short) 20);
// 产生表格标题行
XSSFRow row = sheet.createRow(0);
for (short i = 0; i < headers.length; i++) {
XSSFCell cell = row.createCell(i);
XSSFRichTextString text = new XSSFRichTextString(headers[i]);
cell.setCellValue(text);
}
try {
// 遍历集合数据，产生数据行
Iterator<T> it = dataset.iterator();
int index = 0;
while (it.hasNext()) {
index++;
row = sheet.createRow(index);
T t = (T) it.next();
// 利用反射，根据javabean属性的先后顺序，动态调用getXxx()方法得到属性值
Field[] fields = t.getClass().getDeclaredFields();
for (short i = 0; i < headers.length; i++) {
XSSFCell cell = row.createCell(i);
Field field = fields[i];
String fieldName = field.getName();
String getMethodName = "get" + fieldName.substring(0, 1).toUpperCase() + fieldName.substring(1);
Class tCls = t.getClass();
Method getMethod = tCls.getMethod(getMethodName, new Class[] {});
Object value = getMethod.invoke(t, new Object[] {});
// 判断值的类型后进行强制类型转换
String textValue = null;
// 其它数据类型都当作字符串简单处理
if(value != null && value != ""){
textValue = value.toString();
}
if (textValue != null) {
XSSFRichTextString richString = new XSSFRichTextString(textValue);
cell.setCellValue(richString);
}
}
}
getExportedFile(workbook, fileName,response);
} catch (Exception e) {
e.printStackTrace();
}
}

/**
*
* 方法说明: 指定路径下生成EXCEL文件
* @return
*/
public void getExportedFile(XSSFWorkbook workbook, String name,HttpServletResponse response) throws Exception {
BufferedOutputStream fos = null;
try {
String fileName = name + ".xlsx";
response.setContentType("application/x-msdownload");
response.setHeader("Content-Disposition", "attachment;filename=" + new String( fileName.getBytes("gb2312"), "ISO8859-1" ));
fos = new BufferedOutputStream(response.getOutputStream());
workbook.write(fos);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (fos != null) {
fos.close();
}
}
}

}