java 压缩 InputStream，返回 InputStream（在内存中，没有文件）
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Zipping InputStream, returning InputStream (in memory, no file)
提问by user1156544
I am trying to do compress an InputStream and return an InputStream:
我正在尝试压缩 InputStream 并返回 InputStream：
public InputStream compress (InputStream in){
// Read "in" and write to ZipOutputStream
// Convert ZipOutputStream into InputStream and return
}
I am compressing one file (so I could use GZIP) but will do more in future (so I opted for ZIP). In most of the places:
我正在压缩一个文件（所以我可以使用 GZIP）但将来会做更多（所以我选择了 ZIP）。在大多数地方：
How can I convert ZipInputStream to InputStream?
They use toBytesArray() or getBytes() which do not exist (!) - ZipOutputStream
如何将 ZipInputStream 转换为 InputStream？
他们使用不存在的 toBytesArray() 或 getBytes() (!) - ZipOutputStream
My problems are:
我的问题是：
How do I convert the ZipOutPutStream into InputStream if such methods don't exist?
When creating the ZipOutPutStream() there is no default constructor. Should I create a new ZipOutputStrem(new OutputStream() ) ??
如果此类方法不存在，如何将 ZipOutPutStream 转换为 InputStream？
创建 ZipOutPutStream() 时没有默认构造函数。我应该创建一个新的 ZipOutputStrem(new OutputStream()) 吗？？
采纳答案by user1156544
- Solved it with a ByteArrayOutputStream which has a .toByteArray()
- Same here, passing the aforementioned element
- 用具有 .toByteArray() 的 ByteArrayOutputStream 解决了它
- 同样在这里，传递上述元素
回答by soda
Something like that:
类似的东西：
private InputStream compress(InputStream in, String entryName) throws IOException {
final int BUFFER = 2048;
byte buffer[] = new byte[BUFFER];
ByteArrayOutputStream out = new ByteArrayOutputStream();
ZipOutputStream zos = new ZipOutputStream(out);
zos.putNextEntry(new ZipEntry(entryName));
int length;
while ((length = in.read(buffer)) >= 0) {
zos.write(buffer, 0, length);
}
zos.closeEntry();
zos.close();
return new ByteArrayInputStream(out.toByteArray());
}
