ReplaceAll替换除我指定的内容以外的所有内容

Question

I wish to replace all instances of a pipe in a specific string with something else. However, not only is it not replacing the specified string but instead replacing all blank spaces. Example:

String cleanTitle = StringEscapeUtils.escapeHtml("Bacon is | good");
out.println(cleanTitle.replaceAll("|", "*"))

This example is outputting *B*a*c*o*n*i*s*|*g*o*o*d*

I need it to say Bacon is * good

-The function escapeHTML is necessary for my interface, despite this example not using it for my question.

Answer 1

You need to escape the pipe in your expression, so use:

cleanTitle.replaceAll("\\|", "*")

See also

• http://www.regular-expressions.info/characters.html
• http://www.regular-expressions.info/alternation.html
• http://docs.oracle.com/javase/6/docs/api/java/util/regex/Pattern.html

Answer 2

The String#replaceAll() does a regex matching and replacement. The | is a special character in regex and therefore needs to be escaped with \\ as answered by Jasper. However, you actually wanted a simple char-by-char search and replacement. The String#replaceAll() is the wrong tool for the purpose. You should be using String#replace() instead.

out.println(cleanTitle.replace('|', '*'));