java - 在输出中打印特殊字符和空格

Question

I have situation where I am reading from a file that contains special characters like ,$@%! along with spaces. for example:

I_am_here!!! really,__am_I_here?

In the string above I am show a space with underscore just to show that I can come across multiple spaces (like two before am) as well as special characters. So I am just using _ as a visual aid. In the real file it is actually a space or multiple spaces.

How can I read this file from input and also keep track of them. Is it possible to isolate the special characters and spaces and print them to the output along with the words read. I guess in short I want to preserve the special characters and spaces while modify the words that program reads.

for example the input string:

I_am_here!!! really,__am_I_here?

would become:

I_am_here!!! really,__2_I_2?

Here I am reading the input string, counting the words that occur more than once and print out the output along with spaces and special characters that occurred in the original input. How can I do this in Java? thanks

Answer 1

To find words in a string, the easiest is to use a regular expression. The regex \\p{L}+ will find any sequence of one or more Unicode letters.

To replace such words with a value that isn't know until the word has been found, you can use the appendReplacement() and appendTail() methods of the Matcher used to find the words.

Since you want to count how many times a word has been seen before, you can use a Map<String, Integer> to maintain a map of words already seen, and a count of how many times it has been seen so far.

This is how it would work:

String input = "I am here!!! really,  am I here?  Why, yes I really am!";

Map<String, Integer> wordCount = new HashMap<>();
StringBuffer buf = new StringBuffer();
Matcher m = Pattern.compile("\\p{L}+").matcher(input);
while (m.find()) {
    String word = m.group();
    Integer count = wordCount.get(word);
    if (count == null)
        wordCount.put(word, 1);
    else {
        wordCount.put(word, ++count);
        m.appendReplacement(buf, count.toString());
    }
}
String output = m.appendTail(buf).toString();

System.out.println(input);
System.out.println(output);

OUTPUT

I am here!!! really,  am I here?  Why, yes I really am!
I am here!!! really,  2 2 2?  Why, yes 3 2 3!