StringCompressUtil.java

public class StringCompressUtil {

    private static final String DEFAULT_ENCODING = "UTF-8";

    public static String compress(final String str) throws IOException {
        if (StringUtils.isEmpty(str)) {
            return str;
        }
        String result;
        try (final ByteArrayOutputStream out = new ByteArrayOutputStream()) {
            // must close gzip first or the out will be empty anyway
            try (final GZIPOutputStream gzip = new GZIPOutputStream(out)) {
                gzip.write(str.getBytes(DEFAULT_ENCODING));
            }
            result = out.toString(CharEncoding.ISO_8859_1);
        }
        return result;
    }

    public static String uncompress(final String str) throws IOException {
        if (StringUtils.isEmpty(str)) {
            return str;
        }
        String result;
        try (final ByteArrayOutputStream out = new ByteArrayOutputStream();
                final ByteArrayInputStream in = new ByteArrayInputStream(
                        str.getBytes(CharEncoding.ISO_8859_1));
                final GZIPInputStream gunzip = new GZIPInputStream(in);) {
            // from commons IO IOUtils simply replace it by while read and write
            IOUtils.copy(gunzip, out);
            result = out.toString(DEFAULT_ENCODING);
        }
        return result;
    }
}