springboot:upload

FileUploadConfiguration.java
===================================================
@Configuration
public class FileUploadConfiguration {

@Bean
public MultipartConfigElement multipartConfigElement() {
MultipartConfigFactory factory = new MultipartConfigFactory();
// 设置文件大小限制 ,超出设置页面会抛出异常信息，
// 这样在文件上传的地方就需要进行异常信息的处理了;
factory.setMaxFileSize("256KB"); // KB,MB
/// 设置总上传数据总大小
factory.setMaxRequestSize("512KB");
// Sets the directory location where files will be stored.
// factory.setLocation("路径地址");
return factory.createMultipartConfig();
}

}
===================================================
Controller.java
===================================================
/**
* 文件上传具体实现方法（单文件上传）
*
* @param file
* @return <form method="POST" enctype="multipart/form-data" action="/upload">
* <p>
* 文件：<input type="file" name="file" />
* </p>
* <p>
* <input type="submit" value="上传" />
* </p>
* </form>
*/
@RequestMapping(value = "/upload", method = RequestMethod.POST)
@ResponseBody
public String upload(@RequestParam("file") MultipartFile file) {
if (!file.isEmpty()) {
try {
// 这里只是简单例子，文件直接输出到项目路径下。
// 实际项目中，文件需要输出到指定位置，需要在增加代码处理。
// 还有关于文件格式限制、文件大小限制，详见：中配置。
BufferedOutputStream out = new BufferedOutputStream(
new FileOutputStream(new File(file.getOriginalFilename())));
out.write(file.getBytes());
out.flush();
out.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
return "上传失败," + e.getMessage();
} catch (IOException e) {
e.printStackTrace();
return "上传失败," + e.getMessage();
}
return "上传成功";
} else {
return "上传失败，因为文件是空的.";
}
}

/**
* 多文件上传 主要是使用了MultipartHttpServletRequest和MultipartFile
*
* @param request
* @return <form method="POST" enctype="multipart/form-data"
* action="/upload/batch">
* <p>
* 文件1：<input type="file" name="file" />
* </p>
* <p>
* 文件2：<input type="file" name="file" />
* </p>
* <p>
* 文件3：<input type="file" name="file" />
* </p>
* <p>
* <input type="submit" value="上传" />
* </p>
* </form>
*/
@RequestMapping(value = "/upload/batch", method = RequestMethod.POST)
public
@ResponseBody
String batchUpload(HttpServletRequest request) {
List<MultipartFile> files = ((MultipartHttpServletRequest) request).getFiles("file");
MultipartFile file = null;
BufferedOutputStream stream = null;
for (int i = 0; i < files.size(); ++i) {
file = files.get(i);
if (!file.isEmpty()) {
try {
byte[] bytes = file.getBytes();
stream = new BufferedOutputStream(new FileOutputStream(new File(file.getOriginalFilename())));
stream.write(bytes);
stream.close();
} catch (Exception e) {
stream = null;
return "You failed to upload " + i + " => " + e.getMessage();
}
} else {
return "You failed to upload " + i + " because the file was empty.";
}
}
return "upload successful";
}