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Add escape "\" in front of special character for a string

I have a simple SQL query where I check whether the query matches any of the fields I have. I'm using LIKE statement for this. One of my field can have special characters and so does the search query. So I'm looking for a solution where I need to an escape "\" in front of the special character.
query = "hello+Search}query"
I need the above to change to
query = "hello\+Search\}query"
Is there a simple way of doing this other than searching for each special character separately and adding the "\". Because if I don't have the escape character I will get the error message
java.util.regex.PatternSyntaxException: Dangling meta character '+' near index 0
Thanks in advance

Decide which special characters you want to escape and just call
query.replace("}", "\\}")
You may keep all special characters you allow in some array then iterate it and replace the occurrences as exemplified.
This method replaces all regex meta characters.
public String escapeMetaCharacters(String inputString){
final String[] metaCharacters = {"\\","^","$","{","}","[","]","(",")",".","*","+","?","|","<",">","-","&","%"};
for (int i = 0 ; i < metaCharacters.length ; i++){
if(inputString.contains(metaCharacters[i])){
inputString = inputString.replace(metaCharacters[i],"\\"+metaCharacters[i]);
}
}
return inputString;
}
You could use it as query=escapeMetaCharacters(query);
Don't think that any library you would find would do anything more than that. At best it defines a complete list of specialCharacters.

There is actually a better way of doing this in a sleek manner.
String REGEX = "[\\[+\\]+:{}^~?\\\\/()><=\"!]";
StringUtils.replaceAll(inputString, REGEX, "\\\\$0");

You need to use \\ to introduce a \ into a string literal; that is you need to escape the \. (A single backslash is used to introduce special characters into a string: e.g. \t is a tab.)
query = "hello\\+Search\\}query" is what you need.

I had to do same thing in javascript. I came up with below solution. I think it might help someone.
function escapeSpecialCharacters(s){
let arr = s.split('');
arr = arr.map(function(d){
return d.replace(/[-\/\\^$*+?.()|[\]{}]/g, '\\'+d)
});
let reg = new RegExp(arr.join(''));
return reg;
}
let newstring = escapeSpecialCharacters("hello+Search}query");

If you want to use Java 8+ and Streams, you could do something like:
private String escapeSpecialCharacters(String input) {
List<String> specialCharacters = Lists.newArrayList("\\","^","$","{","}","[","]","(",")",".","*","+","?","|","<",">","-","&","%");
return Arrays.stream(input.split("")).map((c) -> {
if (specialCharacters.contains(c)) return "\\" + c;
else return c;
}).collect(Collectors.joining());
}

The simple version ( without deprecated StringUtils.replaceAll ):
String regex = "[\\[+\\]+:{}^~?\\\\/()><=\"!]";
String query = "hello+Search}query";
String replaceAll = query.replaceAll(regex, "\\\\$0");

Splitting string on the basis of keyword

I have string
String x="http://www.allindiaflorist.com/imgs/arrangemen4.jpg***http://storyofpakistan.com/wp-content/uploads/2011/11/Rukn-AlaminMultan.jpg***" ;
I want to extract string on the basis of *** so I should get array of size 2,
I am doing this,.
String[] explode=a.split("//***");
img1=explode[0]; //`it gives java.util.regex.patternSyntaxException`
I also tried
String[] explode=a.split("***");
img1=explode[0]; //`it gives java.util.regex.patternSyntaxException`
I am ok to write my custom generic function that can search for *** but I want to why split() is not working
Thanks

Use Pattern#quote:
String[] explode=a.split(Pattern.quote("***"));
Now you don't have to break your head on what special character you need to escape. The method "returns a literal pattern String for the specified String".
(For the sake of clarification, you're getting the error because you should escape each *).

Use regex [*]{3}.Try,
String x="htt.....
String arr[] =x.split("[*]{3}");

String str = "http://www.allindiaflorist.com/imgs/arrangemen4.jpg***http://storyofpakistan.com/wp-content/uploads/2011/11/Rukn-AlaminMultan.jpg***";
String delim = "\\*\\*\\*";
String[] arr= str.split(delim);
System.out.println(arr[0]);
System.out.println(arr[1]);
output
http://www.allindiaflorist.com/imgs/arrangemen4.jpg
http://storyofpakistan.com/wp-content/uploads/2011/11/Rukn-AlaminMultan.jpg

You can try this:
String[] explode=a.split("\\Q***\\E");
\Q Start quoting the regex.
\E End quoting the regex.
Basically, between \Q and \E the metacharacter * will be considered as a plain character (ie *) with no special meaning.

Escape * using \\
String[] arr=x.split("\\*\\*\\*");

try this code it will work you have given wrong regx pattern.
it should be inside[]
public static void main(String args[])
{
String x="http://www.allindiaflorist.com/imgs/arrangemen4.jpg***http://storyofpakistan.com/wp-content/uploads/2011/11/Rukn-AlaminMultan.jpg***" ;
String[] explode=x.split("[***]");
String img1=explode[0];
System.out.println(img1);
}

Java: String split acting weird

public String getPriceString() {
String priceString = "45.0";
String[] priceStringArray = priceString.split(".");
return priceStringArray.length + "";
}
Why does this give me a 0, zero? Shouldn't this be 2?

The argument to split() is a regular expression, and dot has a special meaning in regular expressions (it matches any character).
Try priceString.split("[.]");

You need to escape . like that
String[] priceStringArray = priceString.split("\\.");
split takes regular expression as a parameter and . means any character.
http://docs.oracle.com/javase/6/docs/api/java/util/regex/Pattern.html#sum

escape . with backslash like \\.. . is a regex metacharacter for anything. you will have to escape it with \\. in order to make it treat as a normal character
String priceString = "45.0";
String[] priceStringArray = priceString.split("\\.");

String.split takes a regular expression pattern. You're passing in . which means you want to split on any character.
You could use "\\." as the pattern to split on - but personally I'd use Guava instead:
private static final Splitter DOT_SPLITTER = Splitter.on('.');
...
(If you're not already using Guava, you'll find loads of goodies in there.)

You need to escape . as \\. because . has special meaning in regex.
String priceString = "45.0";
String[] priceStringArray = priceString.split("\\.");
return priceStringArray.length + "";

Use String[] priceStringArray = priceString.split("\\.");
You will have to use escape sequence.

How to remove a carriage return from a string

String s ="SSR/DANGEROUS GOODS AS PER ATTACHED SHIPPERS
/DECLARATION 1 PACKAGE
NFY
/ACME CONSOLIDATORS"
How to strip the space between "PACKAGE" and "NFY" ?

Java's String.replaceAll in fact takes a regular expression. You could remove all newlines with:
s = s.replaceAll("\\n", "");
s = s.replaceAll("\\r", "");
But this will remove all newlines.
Note the double \'s: so that the string that is passed to the regular expression parser is \n.
You can also do this, which is smarter:
s = s.replaceAll("\\s{2,}", " ");
This would remove all sequences of 2 or more whitespaces, replacing them with a single space. Since newlines are also whitespaces, it should do the trick for you.

Try this code:
s = s.replaceAll( "PACKAGE\\s*NFY", "PACKAGE NFY" );

s = s.replaceAll("[\\n\\r]", "");

Have you tried a replace function? Something in the lines of:
youString.Replace("\r", "")

string = string.replace(/\s{2,}/g, ' ');

Use String.split() with multiple delimiters

I need to split a string base on delimiter - and .. Below are my desired output.
AA.BB-CC-DD.zip ->
AA
BB
CC
DD
zip
but my following code does not work.
private void getId(String pdfName){
String[]tokens = pdfName.split("-\\.");
}

I think you need to include the regex OR operator:
String[]tokens = pdfName.split("-|\\.");
What you have will match:
[DASH followed by DOT together] -.
not
[DASH or DOT any of them] - or .

Try this regex "[-.]+". The + after treats consecutive delimiter chars as one. Remove plus if you do not want this.

You can use the regex "\W".This matches any non-word character.The required line would be:
String[] tokens=pdfName.split("\\W");

The string you give split is the string form of a regular expression, so:
private void getId(String pdfName){
String[]tokens = pdfName.split("[\\-.]");
}
That means to split on any character in the [] (we have to escape - with a backslash because it's special inside []; and of course we have to escape the backslash because this is a string). (Conversely, . is normally special but isn't special inside [].)

Using Guava you could do this:
Iterable<String> tokens = Splitter.on(CharMatcher.anyOf("-.")).split(pdfName);

For two char sequence as delimeters "AND" and "OR" this should be worked. Don't forget to trim while using.
String text ="ISTANBUL AND NEW YORK AND PARIS OR TOKYO AND MOSCOW";
String[] cities = text.split("AND|OR");
Result : cities = {"ISTANBUL ", " NEW YORK ", " PARIS ", " TOKYO ", " MOSCOW"}

pdfName.split("[.-]+");
[.-] -> any one of the . or - can be used as delimiter
+ sign signifies that if the aforementioned delimiters occur consecutively we should treat it as one.

I'd use Apache Commons:
import org.apache.commons.lang3.StringUtils;
private void getId(String pdfName){
String[] tokens = StringUtils.split(pdfName, "-.");
}
It'll split on any of the specified separators, as opposed to StringUtils.splitByWholeSeparator(str, separator) which uses the complete string as a separator

String[] token=s.split("[.-]");

It's better to use something like this:
s.split("[\\s\\-\\.\\'\\?\\,\\_\\#]+");
Have added a few other characters as sample. This is the safest way to use, because the way . and ' is treated.

Try this code:
var string = 'AA.BB-CC-DD.zip';
array = string.split(/[,.]/);

You may also specified regular expression as argument in split() method ..see below example....
private void getId(String pdfName){
String[]tokens = pdfName.split("-|\\.");
}

s.trim().split("[\\W]+")
should work.

you can try this way as split accepts varargs so we can pass multiple parameters as delimeters
String[]tokens = pdfName.split("-",".");
you can pass as many parameters that you want.

If you know the sting will always be in the same format, first split the string based on . and store the string at the first index in a variable. Then split the string in the second index based on - and store indexes 0, 1 and 2. Finally, split index 2 of the previous array based on . and you should have obtained all of the relevant fields.
Refer to the following snippet:
String[] tmp = pdfName.split(".");
String val1 = tmp[0];
tmp = tmp[1].split("-");
String val2 = tmp[0];
...