如何从Java中删除字符串中的\\ u200B（零长度空白Unicode字符）？

Question

My application is using Spring Integration for email polling from Outlook mailbox.

As, it is receiving the String ( email body )from an external system (Outlook), So I have no control over it.

For Example,

String emailBodyStr= "rejected by sundar14-\u200B.";

Now I am trying to remove the unicode character \​ from this String.

What I tried already.

Try#1:

emailBodyStr = emailBodyStr.replaceAll("\u200B", "");

Try#2:

`emailBodyStr = emailBodyStr.replaceAll("\u200B", "").trim();`

Try#3 (using Apache Commons):

StringEscapeUtils.unescapeJava(emailBodyStr);

Try#4:

StringEscapeUtils.unescapeJava(emailBodyStr).trim();

Nothing worked till now.

When I tried to print this String using below code.

logger.info("Comment BEFORE:{}",emailBodyStr);
logger.info("Comment AFTER :{}",emailBodyStr);

In Eclipse console, it is NOT printing unicode char,

Comment BEFORE:rejected by sundar14-​.

But the same code prints the unicode char in Linux console as below.

Comment BEFORE:rejected by sundar14-\​.

I read some examples where str.replace() is recommended, but please note that examples uses javascript, PHP and not Java.

Answer 1

Finally, I am able to remove ' Zero Width Space ' character by using ' Unicode Regex '.

String plainEmailBody = new String();
plainEmailBody = emailBodyStr.replaceAll("[\\p{Cf}]", "");

Reference to find the category of Unicode characters.

1. Character class from Java .

Character class from Java lists all of these unicode categories.

2. Website: http://www.fileformat.info/

3. Website: http://www.regular-expressions.info/ => Unicode Regular Expressions

Note 1: As I received this string from Outlook Email Body - none of the approaches listed in my question was working.

My application is receiving a String from an external system ( Outlook ), So I have no control over it.

Note 2: This SO answer helped me to know about Unicode Regular Expressions .