前后端分离，前端如何下载Excel
目录：
- 方式一：通过点击链接自动下载
- 方式二：后端生成Excel文件后存入oss，然后将返回地址给前端，由前端下载
第一步：导入jar包
一.通过点击链接自动下载cn.hutool hutool-all5.7.13 org.apache.poi poi-ooxml5.0.0
@GetMapping("/downloadExcel")
@ResponseBody
public void downLoadFile(HttpServletResponse response) {
Map row1 = new linkedHashMap<>();
row1.put("name", "苹果手机");
row1.put("companyName", "苹果科技有限公司");
row1.put("companyLogo", "https://iiot-dev.fxs100.cn/iiot/oauth/2021/6/21/3061624240679082_183_196.jpg");
row1.put("companyProfile", "苹果科技有限公司有限公司是中国信息通信研究院主持组建、中信国安战略注资的高新技术企业。十余年来围绕移动寻址、企业级SaaS、移动互联网标识入口等展开生态布局，是全国领先的移动营销服务商。");
row1.put("personPhone", "010-82512114");
row1.put("httpName", "https://apple.com");
row1.put("column", "官网首页：https://apple.com");
Map row2 = new linkedHashMap<>();
row2.put("name", "华为手机");
row2.put("companyName", "华为科技有限公司");
row2.put("companyLogo", "https://iiot-dev.fxs100.cn/iiot/oauth/2021/6/21/3061624240679082_183_196.jpg");
row2.put("companyProfile", "华为科技有限公司是中国信息通信研究院主持组建、中信国安战略注资的高新技术企业。十余年来围绕移动寻址、企业级SaaS、移动互联网标识入口等展开生态布局，是全国领先的移动营销服务商。");
row2.put("personPhone", "010-82512114");
row2.put("httpName", "https://huawei.com");
row2.put("column", "官网首页：https://huawei.com");
List> rowArr = new ArrayList();
rowArr.add(row1);
rowArr.add(row2);
ArrayList> rows = CollUtil.newArrayList(row1, row2);
// 通过工具类创建writer
//ExcelWriter writer = ExcelUtil.getWriter("f:/user/writeMapTest.xlsx");
// 通过工具类创建writer，默认创建xls格式
ExcelWriter writer = ExcelUtil.getWriter();
//写入图片
for(int i=0; i row = rowArr.get(i);
String companyLogo = row.get("companyLogo").toString();
//读取图片
InputStream inputStream = null;
ByteArrayOutputStream outputStream = null;
byte[] buffer = null;
try {
// 创建URL
URL url = new URL(companyLogo);
// 创建链接
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setConnectTimeout(5000);
inputStream = conn.getInputStream();
outputStream = new ByteArrayOutputStream();
// 将内容读取内存中
buffer = new byte[1024];
int len = -1;
while ((len = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, len);
}
buffer = outputStream.toByteArray();
}catch(IOException e) {
e.printStackTrace();
}finally {
if (inputStream != null) {
try {
// 关闭inputStream流
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
writePic(writer, 2, i+1, buffer, HSSFWorkbook.PICTURE_TYPE_JPEG);
}
//自定义标题别名
writer.addHeaderAlias("name", "关键词");
writer.addHeaderAlias("companyName", "公司名称");
writer.addHeaderAlias("companyLogo", "公司logo");
writer.addHeaderAlias("companyProfile", "简介");
writer.addHeaderAlias("personPhone", "电话");
writer.addHeaderAlias("httpName", "手机域名");
writer.addHeaderAlias("column", "栏目");
// 合并单元格后的标题行，使用默认标题样式
//writer.merge(row1.size() - 1, "");
// 一次性写出内容，使用默认样式，强制输出标题
writer.write(rows, true);
// 关闭writer，释放内存
//writer.close();
//response为HttpServletResponse对象
//response为HttpServletResponse对象
response.setContentType("application/vnd.ms-excel;charset=utf-8");
//test.xls是弹出下载对话框的文件名，不能为中文，中文请自行编码
response.setHeader("Content-Disposition","attachment;filename=test.xls");
ServletOutputStream out =null;
try {
out = response.getOutputStream();
writer.flush(out, true);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
// 关闭writer，释放内存
writer.close();
//此处记得关闭输出Servlet流
IoUtil.close(out);
}
private static void writePic(ExcelWriter writer, int x, int y, byte[] pictureData, int picType) {
Sheet sheet = writer.getSheet();
Drawing drawingPatriarch = sheet.createDrawingPatriarch();
//设置图片单元格位置
ClientAnchor anchor = drawingPatriarch.createAnchor(0, 0, 0, 0, x, y, x + 1, y + 1);
//随单元格改变位置和大小
anchor.setAnchorType(ClientAnchor.AnchorType.MOVE_AND_RESIZE);
//添加图片
int pictureIndex = sheet.getWorkbook().addPicture(pictureData, picType);
drawingPatriarch.createPicture(anchor, pictureIndex);
}
二.直接存入oss，返回地址给前端，由前端下载
public static void main(String[] args) {
Map row1 = new linkedHashMap<>();
row1.put("name", "苹果手机");
row1.put("companyName", "苹果科技有限公司");
row1.put("companyLogo", "https://iiot-dev.fxs100.cn/iiot/oauth/2021/6/21/3061624240679082_183_196.jpg");
row1.put("companyProfile", "苹果科技有限公司有限公司是中国信息通信研究院主持组建、中信国安战略注资的高新技术企业。十余年来围绕移动寻址、企业级SaaS、移动互联网标识入口等展开生态布局，是全国领先的移动营销服务商。");
row1.put("personPhone", "010-82512114");
row1.put("httpName", "https://apple.com");
row1.put("column", "官网首页：https://apple.com");
Map row2 = new linkedHashMap<>();
row2.put("name", "华为手机");
row2.put("companyName", "华为科技有限公司");
row2.put("companyLogo", "https://iiot-dev.fxs100.cn/iiot/oauth/2021/6/21/3061624240679082_183_196.jpg");
row2.put("companyProfile", "华为科技有限公司是中国信息通信研究院主持组建、中信国安战略注资的高新技术企业。十余年来围绕移动寻址、企业级SaaS、移动互联网标识入口等展开生态布局，是全国领先的移动营销服务商。");
row2.put("personPhone", "010-82512114");
row2.put("httpName", "https://huawei.com");
row2.put("column", "官网首页：https://huawei.com");
List> rowArr = new ArrayList();
rowArr.add(row1);
rowArr.add(row2);
ArrayList> rows = CollUtil.newArrayList(row1, row2);
// 通过工具类创建writer
ExcelWriter writer = ExcelUtil.getWriter("f:/user/writeMapTest.xlsx");
//写入图片
for(int i=0; i row = rowArr.get(i);
String companyLogo = row.get("companyLogo").toString();
//读取图片
// 1.网络地址
InputStream inputStream = null;
ByteArrayOutputStream outputStream = null;
byte[] buffer = null;
try {
// 创建URL
URL url = new URL(companyLogo);
// 创建链接
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
conn.setRequestMethod("GET");
conn.setConnectTimeout(5000);
inputStream = conn.getInputStream();
outputStream = new ByteArrayOutputStream();
// 将内容读取内存中
buffer = new byte[1024];
int len = -1;
while ((len = inputStream.read(buffer)) != -1) {
outputStream.write(buffer, 0, len);
}
buffer = outputStream.toByteArray();
}catch(IOException e) {
e.printStackTrace();
}finally {
if (inputStream != null) {
try {
// 关闭inputStream流
inputStream.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
writePic(writer, 2, i+1, buffer, HSSFWorkbook.PICTURE_TYPE_JPEG);
}
//自定义标题别名
writer.addHeaderAlias("name", "关键词");
writer.addHeaderAlias("companyName", "公司名称");
writer.addHeaderAlias("companyLogo", "公司logo");
writer.addHeaderAlias("companyProfile", "简介");
writer.addHeaderAlias("personPhone", "电话");
writer.addHeaderAlias("httpName", "手机域名");
writer.addHeaderAlias("column", "栏目");
// 合并单元格后的标题行，使用默认标题样式
//writer.merge(row1.size() - 1, "");
// 一次性写出内容，使用默认样式，强制输出标题
writer.write(rows, true);
// 关闭writer，释放内存
writer.close();
}
private static void writePic(ExcelWriter writer, int x, int y, byte[] pictureData, int picType) {
Sheet sheet = writer.getSheet();
Drawing drawingPatriarch = sheet.createDrawingPatriarch();
//设置图片单元格位置
ClientAnchor anchor = drawingPatriarch.createAnchor(0, 0, 0, 0, x, y, x + 1, y + 1);
//随单元格改变位置和大小
anchor.setAnchorType(ClientAnchor.AnchorType.MOVE_AND_RESIZE);
//添加图片
int pictureIndex = sheet.getWorkbook().addPicture(pictureData, picType);
drawingPatriarch.createPicture(anchor, pictureIndex);
}
