文件上傳下載

pom.xml

		<!-- 上傳下載 -->
		<dependency>
			<groupId>commons-fileupload</groupId>
			<artifactId>commons-fileupload</artifactId>
			<version>1.3.2</version>
		</dependency>
		<dependency>
			<groupId>commons-io</groupId>
			<artifactId>commons-io</artifactId>
			<version>2.5</version>
		</dependency>

spring.xml配置

	<!-- 上傳下載 -->
	<bean id="multipartResolver"
		class="org.springframework.web.multipart.commons.CommonsMultipartResolver"><!--配置上傳文件 -->
		<property name="defaultEncoding" value="utf-8" /><!--默認字符編碼 -->
		<property name="maxUploadSize" value="10485760000" /><!--上傳文件大小 -->
		<property name="maxInMemorySize" value="4096" /><!--內存中的緩存大小 -->
	</bean>

文件上傳

1. 前端

<form method="post" action="upload.do" enctype="multipart/form-data">
	<input type="file" name="fileName" />
</form>

2. 後臺

	public static String upload(HttpServletRequest request) throws IOException {
		//1.轉化request爲：MultipartHttpServletRequest
		MultipartHttpServletRequest mhsRequest = (MultipartHttpServletRequest) request;
		//2.獲取上傳文件
		CommonsMultipartFile cmFile = (CommonsMultipartFile) mhsRequest.getFile("fileName");
		//3.獲取上傳文件的字節數組
		byte[] fileByte = cmFile.getBytes();
		//4.獲取上傳文件名
		String oldFileName = cmFile.getOriginalFilename();
		//存儲文件的物理路徑
		String uploadPath = "C:\\File\\";
		String url = uploadPath + oldFileName;
		OutputStream os;
		os = new FileOutputStream(url);
		os.write(fileByte);
		os.flush();
		os.close();
		return url;
	}

文件下載

1. 前端
   將該文件的相關的信息傳遞到後臺即可。
2. 後臺
   根據前臺的相關信息得到該文件的路徑，傳入路徑參數執行下載方法

	public static void download(HttpServletResponse response,String url) {
		//截取字符串，獲取文件名
		int i = 24;
		String filename = url.substring(i);
		//獲取輸入流
		try {
			InputStream bis = new BufferedInputStream(new FileInputStream(new File(url)));
			//假如以中文名下載的話,轉碼以免文件名中文亂碼
			filename = URLEncoder.encode(filename,"UTF-8");
			//設置文件下載頭
			response.addHeader("Content-Disposition", "attachment;filename=" + filename);
			//設置文件ContentType類型,這樣設置，會自動判斷下載文件類型
			response.setContentType("multipart/form-data");
			BufferedOutputStream out = new BufferedOutputStream(response.getOutputStream());
			int len = 0;
			while((len = bis.read()) != -1) {
				out.write(len);
				out.flush();
			}
			out.close();
			bis.close();
		} catch (IOException e) {
			e.printStackTrace();
		}
	}