Regular Experssions: Using {} as characters?

[Valgarv]

        String text = "My {burrito} has a hard shell."
+ "{taco}s are yummy.";
String output = "";
String[] replace = {"{burrito}", "{taco}"};
String[] replacer = {"taco", "burrito"};

for (int i = 0; i < replace.length; i++)
{
    output = text.replaceAll(replace[i], replacer[i]);
}

System.out.println(output); 

Gives me a compile error because I can't use { or } in the pattern matching without escaping the characters. However, I don't want to add escape sequances manually. How should I handle this?

[mikeBarr81]

How come you don't want to add them manually? (so I can understand exactly what you're trying to achieve).

Why not just do a find and replace job on all the "{" characters, replacing them with their escape characters?

[Valgarv]

I expect to pull the values in through an external source that I have no control over.

Java must have some method to escape strings?

In php this would be as simple as:

addSlashes(replace[i]);

...do I need to build my own class for java to do this? ::sigh::

[mikeBarr81]

I just had a look through the API for the string class and I couldn't see anything. Looks like you'll have to write it yourself.

[Valgarv]

I tried that.

    public static void main(String[] args) {
        String text = "My {burrito} has a hard shell."
        + "{taco}s are yummy.";
        String output = "";
        String[] replace = {"{burrito}", "{buffalo}"};
        String[] replacer = {"taco", "burrito"};

        for (int i = 0; i < replace.length; i++)
        {
            String slashed = addSlashes(addSlashes(replace[i]));
            output = text.replaceAll(slashed, replacer[0]);
            System.out.println(slashed);
        }
        System.out.println(output);
    }
    
    public static String addSlashes(String theString)
    {
       String newString = "";
       for (int i = 0; i < theString.length(); i++)
       {
           if (theString.charAt(i) == '{' || theString.charAt(i) == '}')
               newString += "\\" + theString.charAt(i);
           else newString += theString.charAt(i);
       }
       return newString;
    } 

If I call addSlashes once the output becomes \{burrito\} which matches nothing. If I call it twice the outout becomes \\{burrito\\} which causes an error. However, if I manually type in \\{burrito\\} as the regx to match it works fine...

[Valgarv]

Nevermind. I got my formatter to work. If some one has a better solution I'm all ears.

[ractoc]

the problem hereis that {} are special characters in a regex. I had this same problem myself. What I did is first call replace('{', '|') and replace('}', '}') to replace the {} with |. This is a character that has no special meaning in a regex. so now I was able to replace them without any problems.

[Valgarv]

hahah that would have been easier than using a loop, if and character array like I did. I always manage to do things the hard way...

I think my method would be more efficient than using replace. I only loop through the character array once. For each character you replace it will loop the entire array.

[sjalle]

You have a problem parsing a string like a regular expression ? Why not download the Apache Jakarta Regexp class ?