a regular expression

Question

Now I have a String and I want to delete \\n and convert \\u to \\\\u.\u003c/i>

If the String contains \\\\u,I will not change it to \\\\\\u.\u003c/i>

I want to use String.replaceAll(), but I don`t know how to write the regular expression.

please help me. thanks.

example:

\\u =\u0026gt; \\\\u\u003c/i>

\\\\u =\u0026gt; \\\\u (do nothing)

Answer 1

Here's a solution using a negative look-behind. (Changes \\u\u003c/code> to \\\\u\u003c/code> only if it is not preceeded by a \\ .)

String in = "lorem ipsum \\u dolor \\\\u sit \n amet";

System.out.println(in);
System.out.println(in.replaceAll("\\n", "")
                     .replaceAll("(?<!\\\\)\\\\u", "\\\\\\\\u")); 

Prints:

lorem ipsum \u dolor \\u sit 
 amet
lorem ipsum \\u dolor \\u sit  amet

• \\n removed
• The first \\u\u003c/code> is changed to \\\\u\u003c/code> but while \\\\u\u003c/code> is preserved as it is.