如何制作multi replace（）java

Question

I have a string with \\r\\n , \\r , \\n or \\" characters in it. How can I replace them faster?

What I already have is:

String s = "Kerner\\r\\n kyky\\r hihi\\n \\\"";
System.out.println(s.replace("\\r\\n", "\n").replace("\\r", "").replace("\\n", "").replace("\\", ""));

But my code does not look beautiful enough. I found on the Internet something like:

replace("\\r\\n|\\r|\\n|\\", "")

I tried that, but it didn't work.

Answer 1

You can wrap it in a method, put /r/n , /n and /r in a list. iterate the list and replace all such characters and return the modified string.

public String replaceMultipleSubstrings(String original, List<String> mylist){
    String tmp = original;
    for(String str: mylist){
        tmp = tmp.replace(str, "");
    }
    return tmp;
}

Test:

mylist.add("\\r");
mylist.add("\\r\\n");
mylist.add("\\n");
mylist.add("\\");  // add back slash

System.out.println("original:" + s);
String x = new Main().replaceMultipleSubstrings(s, mylist);
System.out.println("modified:" + x);

Output:

original:Kerner\r\n kyky\r hihi\n \"
modified:Kerner kyky hihi "

Answer 2

I don't know if your current replacement logic be correct, but it says now that either \\n , \\r , or \\r\\n gets replaced with empty string, and backslash also gets replaced with empty string. If so, then you can try the following regex replace all:

String s = "Kerner\\r\\n kyky\\r hihi\\n \\\"";
System.out.println(s.replaceAll("\\r|\\n|\\r\\n|\\\\", ""));

One problem I saw with your attempt is that you are calling replace() , not replaceAll() , so it would only do a single replacement and then stop.

Answer 3

String.replaceAll() can be used, in your question you tried to use String.replace() which does not interpret regular expressions, only plain replacement strings...

You also need to escape the \\\\ again, ie \\\\\\\\ instead of \\\\

String s = "Kerner\\r\\n kyky\\r hihi\\n \\\"";
System.out.println(s.replaceAll("\\\\r|\\\\n|\\\\\"", ""));

Output

Kerner kyky hihi

Note the differences between String.replaceAll() and String.replace()

String.replaceAll()

Replaces each substring of this string that matches the given regular expression with the given replacement.

String.replace()

Replaces each substring of this string that matches the literal target sequence with the specified literal replacement sequence .

Answer 4

Use a regular expression if you want to do all the replaces in one go. http://www.javamex.com/tutorials/regular_expressions/search_replace.shtml