Java 使url文件变成压缩包并将压缩包下载到浏览器上代码

下面是将url文件转换成压缩包并下载到浏览器上的Java代码示例：

import java.io.*;
import java.net.URL;
import java.nio.channels.Channels;
import java.nio.channels.ReadableByteChannel;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;
import javax.servlet.http.HttpServletResponse;

public class DownloadServlet extends HttpServlet {

   protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String urlString = "http://example.com/yourfile.ext";
        String fileName = "yourfile.zip";
        String mimeType = "application/zip";
        response.setContentType(mimeType);
        response.setHeader("Content-Disposition", "attachment;filename=\"" + fileName + "\"");

        try (ZipOutputStream zos = new ZipOutputStream(response.getOutputStream())) {
            URL url = new URL(urlString);
            try (InputStream is = url.openStream(); ReadableByteChannel rbc = Channels.newChannel(is)) {
                ZipEntry zipEntry = new ZipEntry(fileName);
                zos.putNextEntry(zipEntry);
                zos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
            }
        }
   }
}

请确保替换 `urlString` 为您的 URL 文件和 `fileName` 为您想要下载的文件名。这个例子会将文件压缩成 zip 格式，如果您想要其他格式可以修改 mimeType。