java根据url下载文件到指定路径（支持压缩包）

url是下载地址 

import java.net.URL;
import java.io.File;
import org.apache.commons.io.FileUtils;

@Autowired
private ImProperties imProperties;

private String downloadFromUrl(String url) {
	String fileName = "";
	try {
		String dir = "E:\\";
		URL httpUrl = new URL(url);
		fileName = getFileNameFromUrl(url);
		System.out.println(fileName);
		File file = new File(dir + fileName);
		FileUtils.copyURLToFile(httpUrl, file);
	} catch (Exception e) {
		e.printStackTrace();
	} finally {
		return fileName;
	}
}

private String getFileNameFromUrl(String url) {
	return new Long(System.currentTimeMillis()).toString() + ".gzip";
}