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;
@Slf4j
public 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GET
httpURLConnection.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;
}
@Data
public static class FileMetaInfoDTO {
String fileName;
File file;
public FileMetaInfoDTO(String fileName, File file) {
this.fileName = fileName;
this.file = file;
}
public FileMetaInfoDTO() {
}
}
}