Excel导出学习之道：Java Web利用POI导出Excel简单例子

采用Spring mvc架构：

Controller层代码如下

[java] view
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@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层代码如下：

[java] view
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@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代码如下：

[javascript] view
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<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：

[java] view
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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