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JAVA: Replacing words in string

I want to replace words in a string, but I am having little difficulties. Here is what I want to do. I have string:
String a = "I want to replace some words in this string";
It should work like some kind of a translator. I am doing this with String.replaceAll(), but it doesn't work completely because of this. Let's say I am translating from English to German, than this should be the output (Ich means I in German).
String toTranslate = "I";
String translated = "Ich";
a = a.replaceAll(toTranslate.toLowerCase(), translated.toLowerCase());
Now the output of the String a will be this:
"ich want to replace some words ich**n** **th**ich**s** **str**ich**ng**"
How to replace just the words, not the subwords in the words?

replaceAll uses regex, so you may add word boundaries or look-around mechanisms to check if there are no non-space characters surrounding word you want to replace.
String toTranslate = "I";
String translated = "Ich";
a = a.replaceAll("(?<!\\S)"+toTranslate.toLowerCase()+"(?!\\S)", translated.toLowerCase());
You can also add quotation mechanism to escape any regex metacharacters like + * ( inside word you want to replace. BTW you don't need to change your string to lower case, simply add case-insensitive flag to regex (?i).
a = a.replaceAll("(?i)(?<!\\S)"+Pattern.quote(toTranslate)+"(?!\\S)", translated.toLowerCase());

Use split(" ") for getting each word in the sentence. And then use replaceAll on each word.
String a = "I want to replace some words in this string";
String toTranslate = "I";
String translated = "Ich";
String newString[]=a.split(" ");
for (String string : newString) {
string=string.replaceAll(toTranslate, toTranslate.toLowerCase());//Adding this line ensures you dont miss any uppercase toTranslate
string=string.replaceAll(toTranslate.toLowerCase(), translated.toLowerCase());
System.out.println("after translation ="+string);
}

String toTranslate = "I ";
String translated = "Ich ";
a = a.replaceAll(toTranslate.toLowerCase(), translated.toLowerCase());
If you add a space after the "I" it should replace it when it comes to the word "Ich" but if your word ends in a "I" then thats another problem

If you assume that I will always be capitalized in English as it should be then
a = a.replaceAll(toTranslate, translated);
will work, otherwise you need to replace both cases
a = a.replaceAll(toTranslate, translated);
a = a.replaceAll("([^a-zA-Z])("+toTranslate.toLowerCase()+")([^a-zA-Z])", "$1"+translated.toLowerCase()+"$3");
Here is a working example

Yes, the word boundaries are the solution. I just did this in the regex:
text.replaceAll("\\b" + parts1[i] + "\\b", map.element.value);
Don't be confused with the second argument it's string (from Hash table).

You can use RegEx's word bound, which is \b
String toTranslate = "\\bI\\b";
String translated = "Ich";
a = a.replaceAll(toTranslate.toLowerCase(), translated.toLowerCase());
This should ensure I is separated entirely into its own word
Edit: I misread the question and realized you want whole words. See above, as I have accounted for that

How can i get know that my String contains diacritics?

For Example -
text = Československá obchodní banka;
text string contains diacritics like Č , á etc.
I want to write a function where i will pass this string "Československá obchodní banka" and function will return true if string contains diacritics else false.
I have to handle diacritics and string which contains character which doesn't fall in A-z or a-z range separately.
1) If String contains diacritics then I have to do some XXXXXX on it.
2) If String contains character other than A-Z or a-z and not contains diacritics then do some other operations YYYYY.
I have no idea how to do it.

One piece of knowledge: in Unicode there exists a code for á but the same result one may get with an a and a combining mark-'.
You can use java.text.Normalizer, as follows:
public static boolean hasDiacritics(String s) {
// Decompose any á into a and combining-'.
String s2 = Normalizer.normalize(s, Normalizer.Form.NFD);
return s2.matches("(?s).*\\p{InCombiningDiacriticalMarks}.*");
//return !s2.equals(s);
}

The Normalizer class seems to be able to accomplish this. Some limited testing indicate that
Normalizer.isNormalized(text, Normalizer.Form.NFD)
might be what you need.

How to get an alphanumeric String from any string in Java? [duplicate]

This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
ń ǹ ň ñ ṅ ņ ṇ ṋ ṉ ̈ ɲ ƞ ᶇ ɳ ȵ --> n or Remove diacritical marks from unicode chars
How to replace special characters in a string?
I would like to format some String such as "I>Télé" to something like "itele".
The idea is that I want my String to be lower case (done), without whitespaces (done), no accents or special characters (like >, <, /, %, ~, é, #, ï etc).
It is okay to delete occurences of special characters, but I want to keep letters while removing accents (as I did in my example). Here is what I did, but I don't think that the good solution is to replace every é,è,ê,ë by "e", than do it again for "i","a" etc, and then remove every special character...
String name ="I>télé" //example
String result = name.toLowerCase().replace(" ", "").replace("é","e").........;
The purpose of that is to provide a valid filename for resources for an Android app, so if you have any other idea, I'll take it !

You can use the java.text.Normalizer class to convert your text into normal Latin characters followed by diacritic marks (accents), where possible. So for example, the single-character string "é" would become the two character string ['e', {COMBINING ACUTE ACCENT}].
After you've done this, your String would be a combination of unaccented characters, accent modifiers, and the other special characters you've mentioned. At this point you could filter the characters in your string using only a whitelist to keep what you want (which could be as simple as [A-Za-z0-9] for a regex, depending on what you're after).
An approach might look like:
String name ="I>télé"; //example
String normalized = Normalizer.normalize(name, Form.NFD);
String result = normalized.replaceAll("[^A-Za-z0-9]", "");

You can do something like
String res = ""
for (char c : name.toCharArray()) {
if (Character.isLetter(c) ||Character.isDigit(c))
res += c
}
//Normalize using the method below
http://blog.smartkey.co.uk/2009/10/how-to-strip-accents-from-strings-using-java-6/
public static String stripAccents(String s) {
s = Normalizer.normalize(s, Normalizer.Form.NFD);
s = s.replaceAll("\\p{InCombiningDiacriticalMarks}+", "");
return s;
}

try using ascii code. may this link will help

How to replace special characters in a string?

I have a string with lots of special characters. I want to remove all those, but keep alphabetical characters.
How can I do this?

That depends on what you mean. If you just want to get rid of them, do this:
(Update: Apparently you want to keep digits as well, use the second lines in that case)
String alphaOnly = input.replaceAll("[^a-zA-Z]+","");
String alphaAndDigits = input.replaceAll("[^a-zA-Z0-9]+","");
or the equivalent:
String alphaOnly = input.replaceAll("[^\\p{Alpha}]+","");
String alphaAndDigits = input.replaceAll("[^\\p{Alpha}\\p{Digit}]+","");
(All of these can be significantly improved by precompiling the regex pattern and storing it in a constant)
Or, with Guava:
private static final CharMatcher ALNUM =
CharMatcher.inRange('a', 'z').or(CharMatcher.inRange('A', 'Z'))
.or(CharMatcher.inRange('0', '9')).precomputed();
// ...
String alphaAndDigits = ALNUM.retainFrom(input);
But if you want to turn accented characters into something sensible that's still ascii, look at these questions:
Converting Java String to ASCII
Java change áéőűú to aeouu
ń ǹ ň ñ ṅ ņ ṇ ṋ ṉ ̈ ɲ ƞ ᶇ ɳ ȵ --> n or Remove diacritical marks from unicode chars

I am using this.
s = s.replaceAll("\\W", "");
It replace all special characters from string.
Here
\w : A word character, short for [a-zA-Z_0-9]
\W : A non-word character

You can use the following method to keep alphanumeric characters.
replaceAll("[^a-zA-Z0-9]", "");
And if you want to keep only alphabetical characters use this
replaceAll("[^a-zA-Z]", "");

Replace any special characters by
replaceAll("\\your special character","new character");
ex:to replace all the occurrence of * with white space
replaceAll("\\*","");
*this statement can only replace one type of special character at a time

Following the example of the Andrzej Doyle's answer, I think the better solution is to use org.apache.commons.lang3.StringUtils.stripAccents():
package bla.bla.utility;
import org.apache.commons.lang3.StringUtils;
public class UriUtility {
public static String normalizeUri(String s) {
String r = StringUtils.stripAccents(s);
r = r.replace(" ", "_");
r = r.replaceAll("[^\\.A-Za-z0-9_]", "");
return r;
}
}

string Output = Regex.Replace(Input, #"([ a-zA-Z0-9&, _]|^\s)", "");
Here all the special characters except space, comma, and ampersand are replaced. You can also omit space, comma and ampersand by the following regular expression.
string Output = Regex.Replace(Input, #"([ a-zA-Z0-9_]|^\s)", "");
Where Input is the string which we need to replace the characters.

Here is a function I used to remove all possible special characters from the string
let name = name.replace(/[&\/\\#,+()$~%!.„'":*‚^_¤?<>|#ª{«»§}©®™ ]/g, '').toLowerCase();

You can use basic regular expressions on strings to find all special characters or use pattern and matcher classes to search/modify/delete user defined strings. This link has some simple and easy to understand examples for regular expressions: http://www.vogella.de/articles/JavaRegularExpressions/article.html

You can get unicode for that junk character from charactermap tool in window pc and add \u e.g. \u00a9 for copyright symbol.
Now you can use that string with that particular junk caharacter, don't remove any junk character but replace with proper unicode.

For spaces use "[^a-z A-Z 0-9]" this pattern

Remove end of line characters from end of Java String

I have a string which I'd like to remove the end of line characters from the very end of the string only using Java
"foo\r\nbar\r\nhello\r\nworld\r\n"
which I'd like to become
"foo\r\nbar\r\nhello\r\nworld"
(This question is similar to, but not the same as question 593671)

You can use s = s.replaceAll("[\r\n]+$", "");. This trims the \r and \n characters at the end of the string
The regex is explained as follows:
[\r\n] is a character class containing \r and \n
+ is one-or-more repetition of
$ is the end-of-string anchor
References
regular-expressions.info/Anchors, Character Class, Repetition
Related topics
You can also use String.trim() to trim any whitespace characters from the beginning and end of the string:
s = s.trim();
If you need to check if a String contains nothing but whitespace characters, you can check if it isEmpty() after trim():
if (s.trim().isEmpty()) {
//...
}
Alternatively you can also see if it matches("\\s*"), i.e. zero-or-more of whitespace characters. Note that in Java, the regex matches tries to match the whole string. In flavors that can match a substring, you need to anchor the pattern, so it's ^\s*$.
Related questions
regex, check if a line is blank or not
how to replace 2 or more spaces with single space in string and delete leading spaces only

Wouldn't String.trim do the trick here?
i.e you'd call the method .trim() on your string and it should return a copy of that string minus any leading or trailing whitespace.

The Apache Commons Lang StringUtils.stripEnd(String str, String stripChars) will do the trick; e.g.
String trimmed = StringUtils.stripEnd(someString, "\n\r");
If you want to remove all whitespace at the end of the String:
String trimmed = StringUtils.stripEnd(someString, null);

Well, everyone gave some way to do it with regex, so I'll give a fastest way possible instead:
public String replace(String val) {
for (int i=val.length()-1;i>=0;i--) {
char c = val.charAt(i);
if (c != '\n' && c != '\r') {
return val.substring(0, i+1);
}
}
return "";
}
Benchmark says it operates ~45 times faster than regexp solutions.

If you have Google's guava-librariesin your project (if not, you arguably should!) you'd do this with a CharMatcher:
String result = CharMatcher.any("\r\n").trimTrailingFrom(input);

String text = "foo\r\nbar\r\nhello\r\nworld\r\n";
String result = text.replaceAll("[\r\n]+$", "");

"foo\r\nbar\r\nhello\r\nworld\r\n".replaceAll("\\s+$", "")
or
"foo\r\nbar\r\nhello\r\nworld\r\n".replaceAll("[\r\n]+$", "")