通过网络连接获取文件

1.需要pom

        
            org.apache.tika
            tika-core
            1.14
        

2.FileUtil类

    
    public static File downloadFromUrl(String url ) {
        try {
            URL httpurl = new URL(url);
            HttpURLConnection conn = (HttpURLConnection)httpurl.openConnection();

            // 获取文件后缀名
            String contentType = conn.getContentType();
            MimeTypes allTypes = MimeTypes.getDefaultMimeTypes();
            MimeType jpeg = allTypes.forName(contentType);
            String ext = jpeg.getExtension();

            // 缓存本地
            File f = new File(System.getProperty("user.dir") + "/fileName"+ext);
            FileUtils.copyURLToFile(httpurl, f);
            return f;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }