ExcelUtil

public class ExcelUtil {

/**
* 导出用户的所有列表到excel
* @param userList 用户列表
* @param outputStream 输出流
*/
public static void exportUserExcel(List<User> userList, ServletOutputStream outputStream) {
try {
//1、创建工作簿
HSSFWorkbook workbook = new HSSFWorkbook();
//1.1、创建合并单元格对象
CellRangeAddress cellRangeAddress = new CellRangeAddress(0, 0, 0, 4);//起始行号，结束行号，起始列号，结束列号

//1.2、头标题样式
HSSFCellStyle style1 = createCellStyle(workbook, (short)16);

//1.3、列标题样式
HSSFCellStyle style2 = createCellStyle(workbook, (short)13);

//2、创建工作表
HSSFSheet sheet = workbook.createSheet("用户列表");
//2.1、加载合并单元格对象
sheet.addMergedRegion(cellRangeAddress);
//设置默认列宽
sheet.setDefaultColumnWidth(25);

//3、创建行
//3.1、创建头标题行；并且设置头标题
HSSFRow row1 = sheet.createRow(0);
HSSFCell cell1 = row1.createCell(0);
//加载单元格样式
cell1.setCellStyle(style1);
cell1.setCellValue("用户列表");

//3.2、创建列标题行；并且设置列标题
HSSFRow row2 = sheet.createRow(1);
String[] titles = {"用户名","帐号", "所属部门", "性别", "电子邮箱"};
for(int i = 0; i < titles.length; i++){
HSSFCell cell2 = row2.createCell(i);
//加载单元格样式
cell2.setCellStyle(style2);
cell2.setCellValue(titles[i]);
}

//4、操作单元格；将用户列表写入excel
if(userList != null){
for(int j = 0; j < userList.size(); j++){
HSSFRow row = sheet.createRow(j+2);
HSSFCell cell11 = row.createCell(0);
cell11.setCellValue(userList.get(j).getName());
HSSFCell cell12 = row.createCell(1);
cell12.setCellValue(userList.get(j).getAccount());
HSSFCell cell13 = row.createCell(2);
cell13.setCellValue(userList.get(j).getDept());
HSSFCell cell14 = row.createCell(3);
cell14.setCellValue(userList.get(j).isGender()?"男":"女");
HSSFCell cell15 = row.createCell(4);
cell15.setCellValue(userList.get(j).getEmail());
}
}
//5、输出
workbook.write(outputStream);
workbook.close();
} catch (Exception e) {
e.printStackTrace();
}
}

/**
* 创建单元格样式
* @param workbook 工作簿
* @param fontSize 字体大小
* @return 单元格样式
*/
private static HSSFCellStyle createCellStyle(HSSFWorkbook workbook, short fontSize) {
HSSFCellStyle style = workbook.createCellStyle();
style.setAlignment(HSSFCellStyle.ALIGN_CENTER);//水平居中
style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);//垂直居中
//创建字体
HSSFFont font = workbook.createFont();
font.setBoldweight(HSSFFont.BOLDWEIGHT_BOLD);//加粗字体
font.setFontHeightInPoints(fontSize);
//加载字体
style.setFont(font);
return style;
}

}