不同的结果 ByteArrayOutputStream Java 和 C#

Question

UPD: For answers about encoding: Am use UTF-8 everywhere

I'am try use ByteArrayOutputStream on C#.

I have a string of data:

ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz01234567896ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz01234567896

For java i use the method:

String a = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz01234567896ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz01234567896";
byte[] bArr = a.getBytes();
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(bArr.length);
DeflaterOutputStream deflaterOutputStream = new DeflaterOutputStream(byteArrayOutputStream);
deflaterOutputStream.write(bArr);
deflaterOutputStream.close();
bArr = byteArrayOutputStream.toByteArray();
System.out.println("out: "+Base64.getEncoder().encodeToString(bArr));

So, for as a result i get the string:

eJxzdHJ2cXVz9/D08vbx9fMPCAwKDgkNC4+IjEpMSk5JTUvPyMzKzsnNyy8oLCouKS0rr6isMjA0MjYxNTO3sDRzpEw7AHuTKoM=

For C# am use next code:

string source = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz01234567896ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz01234567896";
byte[] bArr_source = Encoding.UTF8.GetBytes(source);
MemoryStream byteArrayOutputStream = new MemoryStream(bArr_source.Length);
DeflaterOutputStream dos = new DeflaterOutputStream(byteArrayOutputStream);
dos.Write(bArr_source, 0, bArr_source.Length);
dos.Finish();
dos.Close();
bArr_source = byteArrayOutputStream.ToArray();
Console.WriteLine(Convert.ToBase64String(bArr_source));

But in C# iam get a different line:

eJyly8MBgAAAAMCVMp7Zdr9su+kbovsfRTMsxwuiJCuqphumZTuu5wdhFCdplhdlVTdt1w/jNC/rth/ndT8vAEIwgmI4QWI/+wd7kyqD

Why is this happening and how can I fix the problem?

Answer 1

There is no problem .

Both results are valid zlib streams with a check value that checks out, and both decompress to the exact same thing.

There is no assurance that two different compressors will produce the same output with the same input. The only assurance is that when you decompress , you get the same thing you started with. And you are.

I do find it a little odd that the C# code is producing a dynamic block when the result can be four bytes shorter with a fixed block. I suspect that you are using a much older version of .NET that used a compressor that was poorly written (internally at Microsoft). It now uses zlib, and wouldn't make that mistake. Yet I emphasize, the result is still entirely valid and usable.