java打包文件生成zip压缩包

/**
* 打包成zip包
*/
public static void generateZip(OutputStream os, List<File> files) throws Exception {
ZipOutputStream out = null;
try {
byte[] buffer = new byte[1024];
//生成的ZIP文件名为Demo.zip
out = new ZipOutputStream(os);
//需要同时下载的两个文件result.txt ，source.txt
for (File file : files) {
FileInputStream fis = new FileInputStream(file);
out.putNextEntry(new ZipEntry(file.getName()));
int len;
//读入需要下载的文件的内容，打包到zip文件
while ((len = fis.read(buffer)) != -1) {
out.write(buffer, 0, len);
}
out.flush();
out.closeEntry();
fis.close();
}
} catch (Exception e) {
e.printStackTrace();
} finally {
if (out != null) {
out.close();
}
}
}