Replace all "\\" substring with "\\\\"

[getmeidea]

Hi all,

String x = "\\";

This string will have the value \.
Now for any string contains \, i need to replace with \\.

But when i use x = x.replaceAll("\ \", "\\\\");
I am getting runtime exception.

How can i replace this.

[JosAH]

Hi all,

String x = "\\";

This string will have the value \.
Now for any string contains \, i need to replace with \\.

But when i use x = x.replaceAll("\ \", "\\\\");
I am getting runtime exception.

How can i replace this.

You have to double all the backslashes once more because a single backslash
is not only special to the Java compile (javac), it is also special to the regular
expression compiler and interpreter.

kind regards,

Jos

[BigDaddyLH]

What Jos writes is true, but let me suggest a simpler solution.

String has two methods:

String replaceAll(String regex, String replacement)
String replace(CharSequence target, CharSequence replacement)
 

(CharSequence is an interface implemented by String.) Both methods replace "all occurrences", but method replaceAll is more powerful because it takes a pattern string. However, in your case that just gets in the way because backslash has a special meaning in patterns. So prefer to use the second method unless you really need to use a regular expression pattern:

x = x.replace("\\", "\\\\");
 

Read more about regular expressions here:

http://java.sun.com/javase/6/docs/ap...x/Pattern.html