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1 概述
當(dāng)我們?cè)谔幚砦募蟼鞯墓δ軙r(shí),通常會(huì)使用MultipartFile對(duì)象來(lái)表示上傳的文件數(shù)據(jù)。然而,有時(shí)候我們可能已經(jīng)有了一個(gè)File對(duì)象,而不是MultipartFile對(duì)象,需要將File對(duì)象轉(zhuǎn)換為MultipartFile對(duì)象進(jìn)行進(jìn)一步處理。
在Java中,File對(duì)象表示文件在本地文件系統(tǒng)中的引用,而MultipartFile對(duì)象是Spring框架提供的用于處理文件上傳的接口。MultipartFile接口提供了許多有用的方法,例如獲取文件名、獲取文件內(nèi)容、獲取文件大小等。
2 代碼示例
2.1 引入依賴
<!--File轉(zhuǎn)MultipartFile需要test包--><dependency><groupId>org.springframework</groupId><artifactId>spring-test</artifactId><version>5.1.9.RELEASE</version><scope>compile</scope></dependency>
2.2 MultipartFile轉(zhuǎn)File
public static File convert(MultipartFile file) throws IOException {File convFile = new File(file.getOriginalFilename());convFile.createNewFile();FileOutputStream fos = new FileOutputStream(convFile);fos.write(file.getBytes());fos.close();return convFile;}
2.3?File轉(zhuǎn)MultipartFile
//file 轉(zhuǎn)換為 MultipartFileprivate MultipartFile getMulFileByPath(String filePath){FileItemFactory factory = new DiskFileItemFactory(16, null);String textFieldName = "textField";int num = filePath.lastIndexOf(".");String extFile = filePath.substring(num);FileItem item = factory.createItem(textFieldName, "text/plain", true,"MyFileName" + extFile);File newfile = new File(filePath);int bytesRead = 0;byte[] buffer = new byte[8192];try{FileInputStream fis = new FileInputStream(newfile);OutputStream os = item.getOutputStream();while ((bytesRead = fis.read(buffer, 0, 8192))!= -1){os.write(buffer, 0, bytesRead);}os.close();fis.close();}catch (IOException e){e.printStackTrace();}MultipartFile mfile = new CommonsMultipartFile(item);return mfile;}