How to compress a String in Java?

Question

I use GZIPOutputStream or ZIPOutputStream to compress a String (my string.length() is less than 20), but the compressed result is long

Answer 1

If you know that your strings are mostly ASCII you could convert them to UTF-8.

byte[] bytes = string.getBytes("UTF-8");

This may reduce the memory size by about 50%. However, you will get a byte array out and not a string. If you are writing it to a file though, that should not be a problem.

To convert back to a String:

private final Charset UTF8_CHARSET = Charset.forName("UTF-8");
...
String s = new String(bytes, UTF8_CHARSET);