山一程--技术框架--web 技术

目的：汇集 Web 开发（Java 栈）常用代码片段。

1. download

场景：用户在前端请求下载后台生成的文档. 例如：导出 excel.

1. @RestController, @GetMapping

2. 请求方法的入参 HttpServeltResponse

3. HttpServletResponse.reset();

4.exception , httpServletResponse.setHeader("Content-dispotion", "attachment; filename=" +

new String(( fileName + ".xlsx").getBytes("UTF-8"),"ISO-8850-1"));

5. OutputStream os = httpServletResponse.getOutputStream();

Document doc, doc.write(os) ; httpServletResponse.getOutputStream().flush()

6. close(). document.close(); httpServletReponse.getOutputStream().close(); os.close();

 1  @GetMapping("/processResult/downloadResultExcel")
 2     public void getRegProResultExportExcel(HttpServletResponse httpServletResponse) {
 3         OutputStream os = null;
 4 
 5         DateTimeFormatter timeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
 6         LocalDateTime now = LocalDateTime.now();
 7         String timeInfo = now.format(timeFormatter);
 8 
 9         String fileName = "legacy performance" + timeInfo;
10         httpServletResponse.reset();
11         try {
12             httpServletResponse.setHeader("Content-disposition",
13                     "attachment;filename=" +
14                             new String((fileName + ".xlsx").getBytes("UTF-8"),
15                                     "ISO-8859-1"));
16             os = httpServletResponse.getOutputStream();
17             archiveDoc.write(os);
18             httpServletResponse.getOutputStream().flush();
19         } catch (IOException ex) {
20         } finally {
21             try {
22                 httpServletResponse.getOutputStream().close();
23                 archiveDoc.close();
24                 os.close();
25             } catch (IOException ex) {
26                 ex.printStackTrace();
27             }
28         }
29     }

前端以 Extjs 为例

url link 直接设置为 GetMap(" xxx" )

windows.location.ref = link

 1 var archiveResultWithExcel = "/legacy/regression/selection/archiveWithExcel";
 2 Ext.define("analytics.view.business.regression.regressionToolbar",{
 3     extend:"Ext.toolbar.Toolbar",
 4     xtype:'regressionToolbar',
 5 
 6     items:[
 7         {
 8             id:'regressionUploadDataId',
 9             text:'upload data',
10             iconCls:'x-fa fa-plus',
11             handler:'regressionProcess'
12         },
13         {
14             id:'archiveResultWithExcelId',
15             text:'export excel',
16             iconCls:'x-fa fa-plus',
17             //disabled:false,
18             handler:function(){
19                 window.location.href = archiveResultWithExcel
20             }
21             /*handler: 'archiveResultWithExcel'*/
22         }
23     ]
24 });

 1 @RestController
 2 @RequestMapping("/dataSource")
 3 public class DataSourceController {
 4 
 5     @PostMapping("/upload")
 6     void uploadFile(HttpServletRequest request,
 7                     @ModelAttribute(value="file")MultipartFile uploadFile){
 8 
 9         String servletContextPath = request.getServletContext().getRealPath("/");
10         String fileFullName =  uploadFile.getOriginalFilename();
11 
12         int indexSuffix = fileFullName.indexOf(".");
13         String fileName = fileFullName.substring(0,indexSuffix);
14 
15         // 将会在 spring boot 项目目录下，创建 temp 文件.
16         // aws AMI 环境 home/ec2-user/
17         try {
18            File  uploadedFile = File.createTempFile(fileName, ".txt",
19                     Paths.get(servletContextPath).toFile());
20             uploadFile.transferTo(uploadedFile);
21         }catch (Exception e){
22             e.printStackTrace();
23         }
24     }