使用httpclient进行文件下载获取文件名获取方式

    先从返回头的content-Disposition中获取，如果没有再从下载的Url中获取。

import lombok.extern.slf4j.Slf4j;import org.apache.commons.lang3.StringUtils;import java.io.*;import java.net.*;import java.util.regex.Matcher;import java.util.regex.Pattern;@Slf4jpublic class FilesUtils {private final static Pattern pattern = Pattern.compile(".*fileName=(.*)");/*** 文件下载** @param httpUrl 下载的url* @return*/public static FileMetaInfoDTO downLoadFromUrl(String httpUrl) throws IOException {File file = null;FileMetaInfoDTO fileMetaInfoDTO = null;try {// 统一资源URL url = new URL(httpUrl);// 连接类的父类，抽象类URLConnection urlConnection = url.openConnection();// http的连接类HttpURLConnection httpURLConnection = (HttpURLConnection) urlConnection;// 设定请求的方法，默认是GEThttpURLConnection.setRequestMethod("GET");// 设置字符编码httpURLConnection.setRequestProperty("Charset", "UTF-8");urlConnection.setConnectTimeout(MccConfigUtil.getDonwLoadTimeOut());// 打开到此 URL 引用的资源的通信链接（如果尚未建立这样的连接）。httpURLConnection.connect();String suffix = getSuffix(httpUrl);if (StringUtils.isEmpty(suffix)) {suffix = ".tmp";}file = File.createTempFile("httpdonwFile", suffix);BufferedInputStream bin = new BufferedInputStream(httpURLConnection.getInputStream());if (!file.getParentFile().exists()) {file.getParentFile().mkdirs();}FileOutputStream out = new FileOutputStream(file);int size = 0;int len = 0;byte[] buf = new byte[1024];while ((size = bin.read(buf)) != -1) {len += size;out.write(buf, 0, size);}bin.close();out.close();String fileName = tryGetFileName(urlConnection);fileMetaInfoDTO = new FileMetaInfoDTO(fileName, file);} catch (MalformedURLException e) {log.error("downLoad file eror url = {} ", httpUrl, e);} catch (IOException e) {log.error("downLoad file eror url = {} ", httpUrl, e);} finally {return fileMetaInfoDTO;}}private static String tryGetFileName(URLConnection conn) {String contentDisposition = null;try {String disposition = conn.getHeaderField("content-Disposition");if (!StringUtils.isEmpty(disposition)) {contentDisposition = URLDecoder.decode(disposition, "UTF-8");Matcher matcher = pattern.matcher(contentDisposition);return matcher.group(1);} else {String path = conn.getURL().getPath();Integer start = path.lastIndexOf('/') + 1;String fileName = path.substring(start);return URLDecoder.decode(fileName, "UTF-8");}} catch (UnsupportedEncodingException e) {log.error("文件名解析失败 url = {}", conn.getURL(), e);} catch (Exception e) {log.error("文件名解析失败 url = {}", conn.getURL(), e);}return null;}/*** 从输入流中获取字节数组** @param inputStream* @return* @throws IOException*/public static byte[] readInputStream(InputStream inputStream) throws IOException {byte[] buffer = new byte[1024];int len = 0;ByteArrayOutputStream bos = new ByteArrayOutputStream();while ((len = inputStream.read(buffer)) != -1) {bos.write(buffer, 0, len);}bos.close();return bos.toByteArray();}public static String getSuffix(String path) {String suffix = StringUtils.substringAfterLast(path, ".");suffix = StringUtils.substringBeforeLast(suffix, "?");suffix = StringUtils.substringBeforeLast(suffix, "@");return "." + suffix;}@Datapublic static class FileMetaInfoDTO {String fileName;File file;public FileMetaInfoDTO(String fileName, File file) {this.fileName = fileName;this.file = file;}public FileMetaInfoDTO() {}}}