我在我的Java应用程序中下载了一些文件并实现了下载监视器对话框.但最近我使用gzip压缩了所有文件,现在下载监视器有点破碎了.
我将文件作为GZIPInputStream打开,并在每次下载KB后更新下载状态.如果文件大小为1MB,则进度可达到4MB是未压缩的大小.我想监视压缩的下载进度.这可能吗?
编辑:澄清:我正在读取GZipInputStream中的字节,这些字节是未压缩的字节.所以这并没有给我正确的文件大小.
这是我的代码:
URL url = new URL(urlString);
HttpURLConnection con = (HttpURLConnection) url.openConnection();
con.connect();
...
File file = new File("bibles/" + name + ".xml");
if(!file.exists())
file.createNewFile();
out = new FileOutputStream(file);
in = new BufferedInputStream(new GZIPInputStream(con.getInputStream()));
byte[] buffer = new byte[1024];
int count;
while((count = in.read(buffer)) != -1) {
out.write(buffer,count);
downloaded += count;
this.stateChanged();
}
...
private void stateChanged() {
this.setChanged();
this.notifyObservers();
}
谢谢你的帮助!
最佳答案
根据规范,
原文链接:https://www.f2er.com/java/438162.htmlGZIPInputStream
是InflaterInputStream
的子类.InflaterInputStream具有protected Inflater inf
字段,其是用于解压缩工作的Inflater
. Inflater.getBytesRead
应该对您的目的特别有用.
不幸的是,GZIPInputStream不会暴露inf,所以可能你必须创建自己的子类并暴露Inflater,例如
public final class ExposedGZIPInputStream extends GZIPInputStream {
public ExposedGZIPInputStream(final InputStream stream) {
super(stream);
}
public ExposedGZIPInputStream(final InputStream stream,final int n) {
super(stream,n);
}
public Inflater inflater() {
return super.inf;
}
}
...
final ExposedGZIPInputStream gzip = new ExposedGZIPInputStream(...);
...
final Inflater inflater = gzip.inflater();
final long read = inflater.getBytesRead();