Java Web利用POI导出Excel简单例子

官方下载：http://poi.apache.org/download.html这里可以下载到它的最新版本和文档

常用组件：

HSSFWorkbook                      excel的文档对象

HSSFSheet                         excel的表单

HSSFRow                           excel的行

HSSFCell                          excel的格子单元

HSSFFont                          excel字体

HSSFDataFormat                    日期格式

HSSFHeader                        sheet头

HSSFFooter                        sheet尾（只有打印的时候才能看到效果）

样式：

HSSFCellStyle                       cell样式

辅助操作包括：

HSSFDateUtil                        日期

HSSFPrintSetup                      打印

HSSFErrorConstants                  错误信息表

一、控制器，将HSSFWorkbook【excel】对象流输出下载到本地

@Controller    
public class StudentExportController{    
    
    @Autowired    
    private StudentExportService studentExportService;    
    
    @RequestMapping(value = "/excel/export")    
    public void exportExcel(HttpServletRequest request, HttpServletResponse response)     
    throws Exception {    
            
        List<Student> list = new ArrayList<Student>();    
        list.add(new Student(1000,"zhangsan","20"));    
        list.add(new Student(1001,"lisi","23"));    
        list.add(new Student(1002,"wangwu","25"));    
        HSSFWorkbook wb = studentExportService.export(list);    
        response.setContentType("application/vnd.ms-excel");    
        response.setHeader("Content-disposition", "attachment;filename=student.xls");    
        OutputStream ouputStream = response.getOutputStream();    
        wb.write(ouputStream);    
        ouputStream.flush();    
        ouputStream.close();    
   }    
} 

二、逻辑处理方法，用于生成HSSFWorkbook【excel】对象

@Service    
public class StudentExportService {    
    
    String[] excelHeader = { "Sno", "Name", "Age"};    
    public HSSFWorkbook export(List<Campaign> list) {    
        HSSFWorkbook wb = new HSSFWorkbook();    
        HSSFSheet sheet = wb.createSheet("Campaign");    
        HSSFRow row = sheet.createRow((int) 0);    
        HSSFCellStyle style = wb.createCellStyle();    
        style.setAlignment(HSSFCellStyle.ALIGN_CENTER);    
    
        for (int i = 0; i < excelHeader.length; i++) {    
            HSSFCell cell = row.createCell(i);    
            cell.setCellValue(excelHeader[i]);    
            cell.setCellStyle(style);    
            sheet.autoSizeColumn(i);    
        }    
    
        for (int i = 0; i < list.size(); i++) {    
            row = sheet.createRow(i + 1);    
            Student student = list.get(i);    
            row.createCell(0).setCellValue(student.getSno());    
            row.createCell(1).setCellValue(student.getName());    
            row.createCell(2).setCellValue(student.getAge());    
        }    
        return wb;    
    }    
}    

三、前端调用

<script>    
function exportExcel(){    
     location.href="excel/export";    
     <!--这里不能用ajax请求，ajax请求无法弹出下载保存对话框-->    
 }    
</script>    

设置Excel样式以及注意点：

String[] excelHeader = { "所属区域（地市）", "机房", "机架资源情况", "", "", "", "",  
    "", "端口资源情况", "", "", "", "", "", "机位资源情况", "", "", "设备资源情况",  
    "", "", "IP资源情况", "", "", "", "", "网络设备数" };  
String[] excelHeader1 = { "", "", "总量(个)", "空闲(个)", "预占(个)", "实占(个)",  
    "自用(个)", "其它(个)", "总量(个) ", "在用(个)", "空闲(个)", "总带宽(M)",  
    "在用带宽(M)", "空闲带宽(M)", "总量(个)", "在用(个)", "空闲(个)", "设备总量(个)",  
    "客户设备(个)", "电信设备(个)", "总量(个)", "空闲(个)", "预占用(个)", "实占用(个)",  
    "自用(个)", "" };  
// 单元格列宽  
int[] excelHeaderWidth = { 150, 120, 100, 100, 100, 100, 100, 100, 100,  
    100, 100, 120, 120, 120, 120, 120, 120, 150, 150, 150, 120,  
    120, 150, 150, 120, 150 };  
  
HSSFWorkbook wb = new HSSFWorkbook();  
HSSFSheet sheet = wb.createSheet("机房报表统计");  
HSSFRow row = sheet.createRow((int) 0);  
HSSFCellStyle style = wb.createCellStyle();  
// 设置居中样式  
style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 水平居中  
style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER); // 垂直居中  
  
// 设置合计样式  
HSSFCellStyle style1 = wb.createCellStyle();  
Font font = wb.createFont();  
font.setColor(HSSFColor.RED.index);  
font.setBoldweight(Font.BOLDWEIGHT_BOLD); // 粗体  
style1.setFont(font);  
style1.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 水平居中  
style1.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER); // 垂直居中  
  
// 合并单元格  
// first row (0-based) last row (0-based) first column (0-based) last  
// column (0-based)  
sheet.addMergedRegion(new CellRangeAddress(0, 1, 0, 0));  
sheet.addMergedRegion(new CellRangeAddress(0, 1, 1, 1));  
sheet.addMergedRegion(new CellRangeAddress(0, 0, 2, 7));  
sheet.addMergedRegion(new CellRangeAddress(0, 0, 8, 13));  
sheet.addMergedRegion(new CellRangeAddress(0, 0, 14, 16));  
sheet.addMergedRegion(new CellRangeAddress(0, 0, 17, 19));  
sheet.addMergedRegion(new CellRangeAddress(0, 0, 20, 24));  
sheet.addMergedRegion(new CellRangeAddress(0, 1, 25, 25));  
// 设置列宽度（像素）  
for (int i = 0; i < excelHeaderWidth.length; i++) {  
    sheet.setColumnWidth(i, 32 * excelHeaderWidth[i]);  
}  
  
// 添加表格头  
for (int i = 0; i < excelHeader.length; i++) {  
    HSSFCell cell = row.createCell(i);  
    cell.setCellValue(excelHeader[i]);  
    cell.setCellStyle(style);  
}  
row = sheet.createRow((int) 1);  
for (int i = 0; i < excelHeader1.length; i++) {  
    HSSFCell cell = row.createCell(i);  
    cell.setCellValue(excelHeader1[i]);  
    cell.setCellStyle(style);  
}  

注意点1：合并单元格    new CellRangeAddress(int,int,int,int)

first row (0-based) ,last row (0-based), first column (0-based),last column (0-based)

 

注意点2：合并单元格

String[] excelHeader = { "所属区域（地市）", "机房", "机架资源情况", "", "", "", "","", "端口资源情况", "", "", "", "", "", "机位资源情况", "", "", "设备资源情况","", "", "IP资源情况", "", "", "", "", "网络设备数" };

合并以后的单元格虽然是一个，但是仍然要保留其单元格内容，此处用空字符串代替，否则后续表头显示不出

 

注意点3：填充单元格

正确写法：

HSSFCell cell = row.createCell(i);

cell.setCellValue(excelHeader1[i]);

cell.setCellStyle(style);

错误写法：

row.createCell(i).setCellValue(excelHeader1[i]);

row.createCell(i).setCellStyle(style);

本人为了省一个HSSFCell对象，使用了错误写法，导致HSSFCell对象创建了2次，最后只保留了样式，而内容无法显示