关于spring-mvc:上传文件异步处理注意事项

问题

上传Excel进行解决 不必用户期待 解决完之后 会邮件告知处理结果
所以是异步解决

public void readExcel(@RequestParam("file") MultipartFile file) {            CompletableFuture.runAsync(() -> {        try {            service.readExcel(file);        } catch (IOException e) {            e.printStackTrace();        }    });}

理论应用的过程中 发现常常上传失败 报错如下

java.io.FileNotFoundException: /private/tmp/upload_2cc08ec8_c3eb_4633_8c0f_0cc20e34ff55_00000000.tmp (No such file or directory)    at java.io.FileInputStream.open0(Native Method)    at java.io.FileInputStream.open(FileInputStream.java:195)    at java.io.FileInputStream.<init>(FileInputStream.java:138)    at org.apache.tomcat.util.http.fileupload.disk.DiskFileItem.getInputStream(DiskFileItem.java:188)    at org.apache.catalina.core.ApplicationPart.getInputStream(ApplicationPart.java:100)    at org.springframework.web.multipart.support.StandardMultipartHttpServletRequest$StandardMultipartFile.getInputStream(StandardMultipartHttpServletRequest.java:297)

起因

申请返回后 会主动删除临时文件 导致理论读取Excel的时候 找不到文件

// org.apache.catalina.core.ApplicationPart#deletepublic void delete() throws IOException {    fileItem.delete();}

解决

复制该临时文件 将复制后的文件传给异步程序处理 解决完之后删除该临时文件

String uuid = UUID.randomUUID().toString().replace('-', '_');String tmpFileName = String.format("/tmp/upload_%s.tmp", uuid);final File tmpFile = new File(tmpFileName);try {    Files.copy(file.getInputStream(), tmpFile.toPath());} catch (IOException e) {    e.printStackTrace();}CompletableFuture.runAsync(() -> {    try {        service.readExcel(tmpFile);    } catch (IOException e) {        e.printStackTrace();    }});

参考文档

https://stackoverflow.com/que...