Java 文件处理

Java 文件处理

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1、获取文件-文件夹

public class UtilFile {

	/**
	 * 递归获取某个文件夹下的所有文件
	 *
	 * @param fileNameList
	 *            存放文件名称的list
	 * @param path
	 *            文件夹的路径
	 * @return	文件名称
	 */
	public static ArrayList<String> getAllFileName(String path, ArrayList<String> fileNameList) {
		ArrayList<String> files = new ArrayList<String>();
		File file = new File(path);
		File[] tempList = file.listFiles();

		for (int i = 0; i < tempList.length; i++) {
			if (tempList[i].isFile()) {
				// 文件路径
				// System.out.println("文 件：" + tempList[i]);
				// fileNameList.add(tempList[i].toString());
				String fName = tempList[i].toString();
				File tempFile = new File(fName.trim());
				String fileName = tempFile.getName();
				// System.out.println("fileName = " + fileName);
				// 获取文件名称添加入list
				files.add(fileName);
				fileNameList.add(tempList[i].getName());
			}
			if (tempList[i].isDirectory()) {
				// 文件夹路径
				// System.out.println("文件夹：" + tempList[i]);
				getAllFileName(tempList[i].getAbsolutePath(), fileNameList);
			}
		}
		return files;
	}

	public static void main(String[] args) {
		ArrayList<String> files = new ArrayList<String>();
		files = UtilFile.getAllFileName("E:/apache-tomcat-8.5.15/webapps/mexx/excel", new ArrayList<String>());
		for (String string : files) {
			System.out.println("文件名:" + string);
		}

	}

}

• files:返回的文件名
• tempList[i].toString():获取到的文件或文件夹完整路径

重点

省去了切割字符串,步骤,避免在不同平台路径问题,直接可以拿到路径最后的文件名

String fName ="E:/apache-tomcat-8.5.15/webapps/mexx/excel";
File tempFile = new File(fName.trim());
String fileName = tempFile.getName();
System.out.println("fileName = " + fileName);

2、文件下载 Controller

   /**
 * 文件下载
 * 
 * @throws IOException
 */
@RequestMapping(value = "/download", method = RequestMethod.GET)
public void download(@RequestParam(value = "filename") String filename, HttpServletRequest request,
	HttpServletResponse response) throws IOException {
	
	// 模拟文件，myfile.txt为需要下载的文件
	//String path = request.getSession().getServletContext().getRealPath("Excel") + "\\" + filename;
	String path =EXCEL_URL + "/" + filename;
	// 获取输入流
	InputStream bis = new BufferedInputStream(new FileInputStream(new File(path)));
	// 转码，免得文件名中文乱码
	filename = URLEncoder.encode(filename, "UTF-8");
	// 设置文件下载头
	response.addHeader("Content-Disposition", "attachment;filename=" + filename);
	// 1.设置文件ContentType类型，这样设置，会自动判断下载文件类型
	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();
	System.out.println(ExcelController.getIpAddr(request)+"下载完成");
}

3、前端显示

<div style="margin-top:30px;">
	<c:forEach items="${filesList }" var="fileName" >
		<button type="button" >${fileName}</button>
	</c:forEach>
</div>