Replace HTML codes with equivalent characters in Java [duplicate]

Answer 1

One of all the other possibilities or existing util methods could be spring-web's org.springframework.web.util.HtmlUtils.htmlUnescape.

Example usage in a self-contained Groovy script:

@Grapes(
    @Grab(group='org.springframework', module='spring-web', version='4.3.0.RELEASE')
)
import org.springframework.web.util.HtmlUtils

println HtmlUtils.htmlUnescape("La élite del tenis no teme al zika y jugará en Río")

Answer 2

Also, is there any way to optimize this regex?

Yes, don't use regex for this task, use Apache StringEscapeUtils from Apache commons lang:

import org.apache.commons.lang.StringEscapeUtils;
...
String withCharacters = StringEscapeUtils.unescapeHtml(yourString);

JavaDoc says:

Unescapes a string containing entity escapes to a string containing the actual Unicode characters corresponding to the escapes. Supports HTML 4.0 entities.

For example, the string "<Français>" will become "<Français>"

If an entity is unrecognized, it is left alone, and inserted verbatim into the result string. e.g. ">&zzzz;x" will become ">&zzzz;x".