1.注入相关依赖
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi-ooxml</artifactId>
</dependency>
2.相关工具类
public class ExcelUtils {
/**
* Excel导出设置Workbook
* @param title 导出Excel文件名称
* @param rowList 第一个List为表头,其余行为表数据
* @param downLoadPic 是否下载图片
* @throws IOException
*/
public static HSSFWorkbook warpSingleWorkbook(String title, List<List<Object>> rowList, Boolean downLoadPic,Integer pos) throws IOException {
if (rowList == null || rowList.isEmpty()) {
throw new NullPointerException("the row list is null");
}
HSSFWorkbook book = new HSSFWorkbook();
// 创建表
HSSFSheet sheet = book.createSheet(title);
// 设置单元格默认宽度为20个字符
sheet.setDefaultColumnWidth(20);
HSSFPatriarch patriarch = sheet.createDrawingPatriarch();
// 设置表头样式
HSSFCellStyle style = book.createCellStyle();
// 设置居左
style.setAlignment(HorizontalAlignment.LEFT);
// 检测表头数据(表头不允许数据为空)
List<Object> head = rowList.get(0);
// 写数据
int size = rowList.get(0).size();
// 第几行
for (int i = 0; i < rowList.size(); i++) {
List<Object> row = rowList.get(i);
if (row == null || row.isEmpty()) {
book.close();
throw new NullPointerException("the "+(i+1)+"th row is null");
}
if (size != row.size()) {
book.close();
throw new IllegalArgumentException("the cell number of "+(i+1)+"th row is different form the first");
}
HSSFRow sr = sheet.createRow(i);
// 第几列
for (int j = 0; j < row.size(); j++) {
// 如果是否下载照片选择了true,由于我们的照片放在第三列,即当循环到序列为2的时候获取到网络图片地址,这里还考虑到了有多张照片的情况,且用逗号拼接成多张照片。
if (downLoadPic && i > 0 && j == pos) {
if(StringUtils.isNotBlank(row.get(j).toString())){
sr.setHeight((short) (1800));
row.forEach(System.out::println);
List<String> images = Arrays.asList(row.get(j).toString().split(","));
int temp = j;
for(String image : images){
// 调用封装好的下载图片方法
drawPictureInfoExcel(book, patriarch, i, j, image);
j++;
}
}
} else {
setExcelValue(sr.createCell(j), row.get(j), style);
}
}
}
return book;
}
/**
* 设置Excel浮点数可做金额等数据统计
* @param cell 单元格类
* @param value 传入的值
*/
public static void setExcelValue(HSSFCell cell, Object value, HSSFCellStyle style){
// 写数据
if (value == null) {
cell.setCellValue("");
}else {
if (value instanceof Integer || value instanceof Long) {
cell.setCellType(CellType.NUMERIC);
cell.setCellValue(Long.valueOf(value.toString()));
} else if (value instanceof BigDecimal) {
cell.setCellType(CellType.NUMERIC);
cell.setCellValue(((BigDecimal)value).setScale(3, RoundingMode.HALF_UP).doubleValue());
} else {
cell.setCellValue(value.toString());
}
cell.setCellStyle(style);
}
}
/**
*
* @param wb
* @param patriarch
* @param rowIndex
* @param columnIndex
* @param pictureUrl
*/
private static void drawPictureInfoExcel(HSSFWorkbook wb,HSSFPatriarch patriarch,int rowIndex, int columnIndex,String pictureUrl){
//rowIndex代表当前行
try {
URL url = new URL(pictureUrl);
//打开链接
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
//设置请求方式为"GET"
conn.setRequestMethod("GET");
//超时响应时间为5秒
conn.setConnectTimeout(5 * 1000);
//通过输入流获取图片数据
InputStream inStream = conn.getInputStream();
//得到图片的二进制数据,以二进制封装得到数据,具有通用性
byte[] data = readInputStream(inStream);
//anchor主要用于设置图片的属性
// dx1:起始单元格的x偏移量,
// dy1:起始单元格的y偏移量,
// dx2:终止单元格的x偏移量,
// dy2:终止单元格的y偏移量,
// col1:起始单元格列序号,从0开始计算;
// row1:起始单元格行序号,从0开始计算,
// col2:终止单元格列序号,从0开始计算;
// row2:终止单元格行序号,从0开始计算,
HSSFClientAnchor anchor = new HSSFClientAnchor(0, 0, 1023, 250,(short) columnIndex, rowIndex, (short) columnIndex, rowIndex);
//Sets the anchor type (图片在单元格的位置)
//0 = Move and size with Cells, 2 = Move but don't size with cells, 3 = Don't move or size with cells.
anchor.setAnchorType(ClientAnchor.AnchorType.DONT_MOVE_AND_RESIZE);
patriarch.createPicture(anchor, wb.addPicture(data, HSSFWorkbook.PICTURE_TYPE_PNG));
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
private static byte[] readInputStream(InputStream inStream) throws Exception{
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
//创建一个Buffer字符串
byte[] buffer = new byte[1024];
//每次读取的字符串长度,如果为-1,代表全部读取完毕
int len = 0;
//使用一个输入流从buffer里把数据读取出来
while( (len=inStream.read(buffer)) != -1 ){
//用输出流往buffer里写入数据,中间参数代表从哪个位置开始读,len代表读取的长度
outStream.write(buffer, 0, len);
}
//关闭输入流
inStream.close();
//把outStream里的数据写入内存
return outStream.toByteArray();
}
3.实现代码
3.1构建工具里所需要的参数
//图片位置
Integer pos = 0;
//是否下载图片
boolean downLoadPic = false;
//构建list存放数据 每个List<Object>代表表格的一行
List<List<Object>> rowList = new ArrayList<List<Object>>();
//获取输出流
ServletOutputStream out = response.getOutputStream();
3.2调用工具类 进行导出
//调用提供的工具类
HSSFWorkbook wb = ExcelUtils.warpSingleWorkbook("表格名称", rowList, downLoadPic, pos);
//设置响应规则
response.setContentType("application/x-download");
response.setCharacterEncoding("UTF-8");
response.addHeader("Content-Disposition", "attachment;filename=" + "表格名称.xls");
//关闭流
wb.write(out);
out.flush();
out.close();
wb.close();