Java Web利用POI導出Excel簡單例子

采用Spring mvc架構： 

Controller層代碼如下 

@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();  
   }  
}  

Service層代碼如下： 

@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;  
    }  
}  

前台的js代碼如下： 

<script>  
function exportExcel(){  
     location.href="excel/export";  
     <!--這里不能用ajax請求，ajax請求無法彈出下載保存對話框-->  
 }  
</script>  

設置Excel樣式以及注意點：

    String[] excelHeader = { "所屬區域（地市）", "機房", "機架資源情況", "", "", "", "",
        "", "端口資源情況", "", "", "", "", "", "機位資源情況", "", "", "設備資源情況",
        "", "", "IP資源情況", "", "", "", "", "網絡設備數" };
    String[] excelHeader1 = { "", "", "總量(個)", "空閑(個)", "預占(個)", "實占(個)",
        "自用(個)", "其它(個)", "總量(個) ", "在用(個)", "空閑(個)", "總帶寬(M)",
        "在用帶寬(M)", "空閑帶寬(M)", "總量(個)", "在用(個)", "空閑(個)", "設備總量(個)",
        "客戶設備(個)", "電信設備(個)", "總量(個)", "空閑(個)", "預占用(個)", "實占用(個)",
        "自用(個)", "" };
    // 單元格列寬
    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("機房報表統計");
    HSSFRow row = sheet.createRow((int) 0);
    HSSFCellStyle style = wb.createCellStyle();
    // 設置居中樣式
    style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 水平居中
    style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER); // 垂直居中

    // 設置合計樣式
    HSSFCellStyle style1 = wb.createCellStyle();
    Font font = wb.createFont();
    font.setColor(HSSFColor.RED.index);
    font.setBoldweight(Font.BOLDWEIGHT_BOLD); // 粗體
    style1.setFont(font);
    style1.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 水平居中
    style1.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER); // 垂直居中

    // 合並單元格
    // 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));
    // 設置列寬度（像素）
    for (int i = 0; i < excelHeaderWidth.length; i++) {
        sheet.setColumnWidth(i, 32 * excelHeaderWidth[i]);
    }

    // 添加表格頭
    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);
    }

注意點1：合並單元格    new CellRangeAddress(int,int,int,int)

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

注意點2：合並單元格

String[] excelHeader = { "所屬區域（地市）", "機房", "機架資源情況", "", "", "", "","", "端口資源情況", "", "", "", "", "", "機位資源情況", "", "", "設備資源情況","", "", "IP資源情況", "", "", "", "", "網絡設備數" };

合並以后的單元格雖然是一個，但是仍然要保留其單元格內容，此處用空字符串代替，否則后續表頭顯示不出

 

注意點3：填充單元格

正確寫法：

HSSFCell cell = row.createCell(i);

cell.setCellValue(excelHeader1[i]);

cell.setCellStyle(style);

錯誤寫法：

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

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

本人為了省一個HSSFCell對象，使用了錯誤寫法，導致HSSFCell對象創建了2次，最后只保留了樣式，而內容無法顯示