我正在 Spring 中创建一个 Web 应用程序，它允许多个用户同时上传文件，也可以通过分段上传文件的方式，这样就不存在内存问题，但我当前的代码只允许 1 个用户一次上传文件。在第一个文件完成之前，第二个文件不会启动。我该如何解决这个问题？
这是我的上传表单:
<body>
<div th:if="${message}">
<h2 th:text="${message}"></h2>
</div>
<div>
<form method="post" enctype="multipart/form-data" action="/">
<table>
<tr><td>File to Upload:</td><td><input type="file" name="file" /></td></tr>
<div id="drop_zone">Drop files here</div>
<output id="list"></output>
<tr><td></td><td><input type="submit" value="Upload" /></td></tr>
</table>
</form>
</div>
<div>
<ul>
<li th:each="file : ${files}">
<a th:href="${file}" th:text="${file}" />
</li>
</ul>
</div>
</body>
这是我的 Controller
package hello;
import hello.storage.StorageFileNotFoundException;
import hello.storage.StorageService;
import org.apache.tomcat.util.http.fileupload.FileItemStream;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.servlet.mvc.method.annotation.MvcUriComponentsBuilder;
import org.springframework.web.servlet.mvc.support.RedirectAttributes;
import java.io.*;
import java.util.stream.Collectors;
@Controller
public class FileUploadController {
private final StorageService storageService;
private static final long serialVersionUID = 3447685998419256747L;
private static final String RESP_SUCCESS = "{\"jsonrpc\" : \"2.0\", \"result\" : \"success\", \"id\" : \"id\"}";
private static final String RESP_ERROR = "{\"jsonrpc\" : \"2.0\", \"error\" : {\"code\": 101, \"message\": \"Failed to open input stream.\"}, \"id\" : \"id\"}";
public static final String JSON = "application/json";
public static final int BUF_SIZE = 2 * 1024;
public static final String FileDir = "C:\\Users\\sshah\\Development\\Uploading Files\\upload-dir\\";
@Autowired
public FileUploadController(StorageService storageService) {
this.storageService = storageService;
}
@GetMapping("/")
public String listUploadedFiles(Model model) throws IOException {
model.addAttribute("files", storageService
.loadAll()
.map(path ->
MvcUriComponentsBuilder
.fromMethodName(FileUploadController.class, "serveFile", path.getFileName().toString())
.build().toString())
.collect(Collectors.toList()));
return "uploadForm";
}
@GetMapping("/files/{filename:.+}")
@ResponseBody
public ResponseEntity<Resource> serveFile(@PathVariable String filename) {
Resource file = storageService.loadAsResource(filename);
return ResponseEntity
.ok()
.header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\""+file.getFilename()+"\"")
.body(file);
}
@PostMapping("/")
public String handleFileUpload(@RequestParam("file") MultipartFile file,
RedirectAttributes redirectAttributes) {
try {
/*storageService.store(file);*/
InputStream ip = file.getInputStream();
saveUploadFile(ip, new File(FileDir + file.getOriginalFilename()));
}
catch (Exception e) {
e.printStackTrace();
}
redirectAttributes.addFlashAttribute("message",
"You successfully uploaded " + file.getOriginalFilename() + "!");
return "redirect:/";
}
@ExceptionHandler(StorageFileNotFoundException.class)
public ResponseEntity handleStorageFileNotFound(StorageFileNotFoundException exc) {
return ResponseEntity.notFound().build();
}
private void saveUploadFile(InputStream input, File dst) throws IOException {
OutputStream out = null;
try {
if (dst.exists()) {
out = new BufferedOutputStream(new FileOutputStream(dst, true),
BUF_SIZE);
} else {
out = new BufferedOutputStream(new FileOutputStream(dst),
BUF_SIZE);
}
byte[] buffer = new byte[BUF_SIZE];
int len = 0;
while ((len = input.read(buffer)) > 0) {
out.write(buffer, 0, len);
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (null != input) {
try {
input.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (null != out) {
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
}
Pom.xml 文件:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.springframework</groupId>
<artifactId>gs-uploading-files</artifactId>
<version>0.1.0</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.4.2.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-configuration-processor</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
最后是我的Applications.properties 文件:
spring.http.multipart.max-file-size=15000MB
spring.http.multipart.max-request-size=15000MB
我刚进入 Spring 大约 3 个月，所以我们将不胜感激。
谢谢!
最佳答案
您可以从<input type="file" name="file" />更改您的html至<input type="file" name="manyfiles" multiple/>这样您就会得到一个可以选择多个文件的表单。
在此之后，您只需更改 Controller 中的 post 方法，以便获得 MultipartFile 数组。您可以遍历该数组并一一处理文件。
@PostMapping("/")
public String handleFileUpload(@RequestParam("manyfiles") MultipartFile[] files,
RedirectAttributes redirectAttributes) {
for(MultipartFile file : files) {
//Your upload code
}
}
编辑:
如果您想要异步上传，请将字节传递给上传方法并将其标记为异步
@Async
public void process(byte[] bs){
//do some long running processing of bs here
}
@PostMapping("/")
public String handleFileUpload(@RequestParam("file") MultipartFile file,
RedirectAttributes redirectAttributes) {
upload.process(IOUtils.toByteArray(file));
}
关于java - Spring中的多用户文件上传，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40856333/