I have a ArrayList of strings LinkSet which contains the following items
["0,3","0,13","0,28","12,3","13,3","28,12"]
I have another list of list pattern2 with the following containing
[[0,3], [0,13,3], [0,28,12,3]]
I would like to match each element pattern of the list LinkSet in my list pattern2 and replace the element found by the position of the match from LinkSet. As a result, I would like to have a list of list with like :
[[0],[1,4],[2,5,3]]
From this new list of list, 0 is the position of the "0,3" from the original list,1 is the position of 0,13 in the original list and so on.
I tried this:
String pattern2="";
for (int k=0; k<graph.LinkSet.size();k++)
{
String temp=""
for(int m=0;m<pattern.size();m++)
{
temp=pattern.get(m).toString();
if (temp.contains("[["+LinkSet.get(k)+"],"))
{
pattern=pattern+"[["+k+"],";
}
else if (temp.contains("["+LinkSet.get(k)+"],"))
{
pattern=pattern+"["+k+"],";
}
else if (temp.contains(", ["+LinkSet.get(k)))
{
pattern=pattern+", ["+k+",";
}
else if (temp.contains(", ["+LinkSet.get(k)))
{
pattern=pattern+", ["+k+",";
}
}
}
//System.out.println("after"+temp);
System.out.println("pattern"+pattern2);
But it does not give me what I would like to have. It gives me
,[,[[[1,2,3],
it seems to overwrite pattern2 for each loop
Looks like the problem is, that you're working on "pattern" and change it inside the innner-loop instead of storing your results in pattern2... But that doesn't explain your results. Also you're messing around with the brackets unnecessarily. And you need to switch the loops to get the result you want.
How about this:
String result = "";
// Loop over pattern
for (int m = 0; m < pattern.size(); m++) {
String patternResult = "";
String patternToBeMatched = pattern.get(m);
// Loop over source
for (int k=0; k<graph.LinkSet.size(); k++) {
String toAnalyse = graph.LinkSet.get(k);
if (toAnalyse.contains(patternToBeMatched){
patternResult = patternResult + k + ", ";
}
}
// Remove additional ", " if not empty and set brackets
if (patternResult.length() > 0){
patternResult = "[" + patternResult.substring(0, patternResult.length() - 2) + "]";
}
result = result + patternResult;
}
result = "[" + result + "]";
I have a string like a1wwa1xxa1yya1zz.
I would like to get every groups starting with a1 until next a1 excluded.
(In my example, i would be : a1ww, a1xx, a1yyand a1zz
If I use :
Matcher m = Pattern.compile("(a1.*?)a1").matcher("a1wwa1xxa1yya1zz");
while(m.find()) {
String myGroup = m.group(1);
}
myGroup capture 1 group every two groups.
So in my example, I can only capture a1ww and a1yy.
Anyone have a great idea ?
Split is a good solution, but if you want to remain in the regex world, here is a solution:
Matcher m = Pattern.compile("(a1.*?)(?=a1|$)").matcher("a1wwa1xxa1yya1zz");
while (m.find()) {
String myGroup = m.group(1);
System.out.println("> " + myGroup);
}
I used a positive lookahead to ensure the capture is followed by a1, or alternatively by the end of line.
Lookahead are zero-width assertions, ie. they verify a condition without advancing the match cursor, so the string they verify remains available for further testing.
You can use split() method, then append "a1" as a prefix to splitted elements:
String str = "a1wwa1xxa1yya1zz";
String[] parts = str.split("a1");
String[] output = new String[parts.length - 1];
for (int i = 0; i < output.length; i++)
output[i] = "a1" + parts[i + 1];
for (String p : output)
System.out.println(p);
Output:
a1ww
a1xx
a1yy
a1zz
I would use an approach like this:
String str = "a1wwa1xxa1yya1zz";
String[] parts = str.split("a1");
for (int i = 1; i < parts.length; i++) {
String found = "a1" + parts[i];
}
String text = "select ename from emp";
I want to know the space index after the word from. How to do it?
If you're specifically looking for the index of the first space after the word "from", you can use:
text.substring(text.indexOf("from")).indexOf(' ');
If you're trying to do something more general, than you'll need to give a bit more information. But the indexOf() method will probably be very useful to you.
Edit: This should actually be
text.indexOf(' ', text.indexOf("from"));
The first version returns the index relative to "from", whereas the second returns the index relative to the original string. (thanks #jpm)
This loop will find all space characters in the given string:
int index = text.indexOf(' ');
while (index >= 0) {
System.out.println(index);
index = text.indexOf(' ', index + 1);
}
The very basic answer might look something like...
String text = "select ename from emp";
text = text.toLowerCase();
if (text.contains("from ")) {
int index = text.indexOf("from ") + "from".length();
System.out.println("Found space # " + index);
System.out.println(text.substring(index));
} else {
System.out.println(text + " does not contain `from `");
}
Or you could use some regular expression (this is a rather poor example, but hay)
Pattern pattern = Pattern.compile("from ");
Matcher matcher = pattern.matcher(text);
String match = null;
int endIndex = -1;
if (matcher.find()) {
endIndex = matcher.end();
}
if (endIndex > -1) {
endIndex--;
System.out.println("Found space # " + endIndex);
System.out.println(text.substring(endIndex));
} else {
System.out.println(text + " does not contain `from `");
}
To find the index of each space you could do something like...
Pattern pattern = Pattern.compile(" ");
Matcher matcher = pattern.matcher(text);
String match = null;
while (matcher.find()) {
System.out.println(matcher.start());
}
Which will output
6
12
17
use indexOf() method. Hope u got the answer
I have a string,
String s = "test string (67)";
I want to get the no 67 which is the string between ( and ).
Can anyone please tell me how to do this?
There's probably a really neat RegExp, but I'm noob in that area, so instead...
String s = "test string (67)";
s = s.substring(s.indexOf("(") + 1);
s = s.substring(0, s.indexOf(")"));
System.out.println(s);
A very useful solution to this issue which doesn't require from you to do the indexOf is using Apache Commons libraries.
StringUtils.substringBetween(s, "(", ")");
This method will allow you even handle even if there multiple occurrences of the closing string which wont be easy by looking for indexOf closing string.
You can download this library from here:
https://mvnrepository.com/artifact/org.apache.commons/commons-lang3/3.4
Try it like this
String s="test string(67)";
String requiredString = s.substring(s.indexOf("(") + 1, s.indexOf(")"));
The method's signature for substring is:
s.substring(int start, int end);
By using regular expression :
String s = "test string (67)";
Pattern p = Pattern.compile("\\(.*?\\)");
Matcher m = p.matcher(s);
if(m.find())
System.out.println(m.group().subSequence(1, m.group().length()-1));
Java supports Regular Expressions, but they're kind of cumbersome if you actually want to use them to extract matches. I think the easiest way to get at the string you want in your example is to just use the Regular Expression support in the String class's replaceAll method:
String x = "test string (67)".replaceAll(".*\\(|\\).*", "");
// x is now the String "67"
This simply deletes everything up-to-and-including the first (, and the same for the ) and everything thereafter. This just leaves the stuff between the parenthesis.
However, the result of this is still a String. If you want an integer result instead then you need to do another conversion:
int n = Integer.parseInt(x);
// n is now the integer 67
In a single line, I suggest:
String input = "test string (67)";
input = input.subString(input.indexOf("(")+1, input.lastIndexOf(")"));
System.out.println(input);`
You could use apache common library's StringUtils to do this.
import org.apache.commons.lang3.StringUtils;
...
String s = "test string (67)";
s = StringUtils.substringBetween(s, "(", ")");
....
Test String test string (67) from which you need to get the String which is nested in-between two Strings.
String str = "test string (67) and (77)", open = "(", close = ")";
Listed some possible ways: Simple Generic Solution:
String subStr = str.substring(str.indexOf( open ) + 1, str.indexOf( close ));
System.out.format("String[%s] Parsed IntValue[%d]\n", subStr, Integer.parseInt( subStr ));
Apache Software Foundation commons.lang3.
StringUtils class substringBetween() function gets the String that is nested in between two Strings. Only the first match is returned.
String substringBetween = StringUtils.substringBetween(subStr, open, close);
System.out.println("Commons Lang3 : "+ substringBetween);
Replaces the given String, with the String which is nested in between two Strings. #395
Pattern with Regular-Expressions: (\()(.*?)(\)).*
The Dot Matches (Almost) Any Character
.? = .{0,1}, .* = .{0,}, .+ = .{1,}
String patternMatch = patternMatch(generateRegex(open, close), str);
System.out.println("Regular expression Value : "+ patternMatch);
Regular-Expression with the utility class RegexUtils and some functions.
Pattern.DOTALL: Matches any character, including a line terminator.
Pattern.MULTILINE: Matches entire String from the start^ till end$ of the input sequence.
public static String generateRegex(String open, String close) {
return "(" + RegexUtils.escapeQuotes(open) + ")(.*?)(" + RegexUtils.escapeQuotes(close) + ").*";
}
public static String patternMatch(String regex, CharSequence string) {
final Pattern pattern = Pattern.compile(regex, Pattern.DOTALL);
final Matcher matcher = pattern .matcher(string);
String returnGroupValue = null;
if (matcher.find()) { // while() { Pattern.MULTILINE }
System.out.println("Full match: " + matcher.group(0));
System.out.format("Character Index [Start:End]«[%d:%d]\n",matcher.start(),matcher.end());
for (int i = 1; i <= matcher.groupCount(); i++) {
System.out.println("Group " + i + ": " + matcher.group(i));
if( i == 2 ) returnGroupValue = matcher.group( 2 );
}
}
return returnGroupValue;
}
String s = "test string (67)";
int start = 0; // '(' position in string
int end = 0; // ')' position in string
for(int i = 0; i < s.length(); i++) {
if(s.charAt(i) == '(') // Looking for '(' position in string
start = i;
else if(s.charAt(i) == ')') // Looking for ')' position in string
end = i;
}
String number = s.substring(start+1, end); // you take value between start and end
String result = s.substring(s.indexOf("(") + 1, s.indexOf(")"));
public String getStringBetweenTwoChars(String input, String startChar, String endChar) {
try {
int start = input.indexOf(startChar);
if (start != -1) {
int end = input.indexOf(endChar, start + startChar.length());
if (end != -1) {
return input.substring(start + startChar.length(), end);
}
}
} catch (Exception e) {
e.printStackTrace();
}
return input; // return null; || return "" ;
}
Usage :
String input = "test string (67)";
String startChar = "(";
String endChar = ")";
String output = getStringBetweenTwoChars(input, startChar, endChar);
System.out.println(output);
// Output: "67"
Another way of doing using split method
public static void main(String[] args) {
String s = "test string (67)";
String[] ss;
ss= s.split("\\(");
ss = ss[1].split("\\)");
System.out.println(ss[0]);
}
Use Pattern and Matcher
public class Chk {
public static void main(String[] args) {
String s = "test string (67)";
ArrayList<String> arL = new ArrayList<String>();
ArrayList<String> inL = new ArrayList<String>();
Pattern pat = Pattern.compile("\\(\\w+\\)");
Matcher mat = pat.matcher(s);
while (mat.find()) {
arL.add(mat.group());
System.out.println(mat.group());
}
for (String sx : arL) {
Pattern p = Pattern.compile("(\\w+)");
Matcher m = p.matcher(sx);
while (m.find()) {
inL.add(m.group());
System.out.println(m.group());
}
}
System.out.println(inL);
}
}
The "generic" way of doing this is to parse the string from the start, throwing away all the characters before the first bracket, recording the characters after the first bracket, and throwing away the characters after the second bracket.
I'm sure there's a regex library or something to do it though.
The least generic way I found to do this with Regex and Pattern / Matcher classes:
String text = "test string (67)";
String START = "\\("; // A literal "(" character in regex
String END = "\\)"; // A literal ")" character in regex
// Captures the word(s) between the above two character(s)
String pattern = START + "(\w+)" + END;
Pattern pattern = Pattern.compile(pattern);
Matcher matcher = pattern.matcher(text);
while(matcher.find()) {
System.out.println(matcher.group()
.replace(START, "").replace(END, ""));
}
This may help for more complex regex problems where you want to get the text between two set of characters.
The other possible solution is to use lastIndexOf where it will look for character or String from backward.
In my scenario, I had following String and I had to extract <<UserName>>
1QAJK-WKJSH_MyApplication_Extract_<<UserName>>.arc
So, indexOf and StringUtils.substringBetween was not helpful as they start looking for character from beginning.
So, I used lastIndexOf
String str = "1QAJK-WKJSH_MyApplication_Extract_<<UserName>>.arc";
String userName = str.substring(str.lastIndexOf("_") + 1, str.lastIndexOf("."));
And, it gives me
<<UserName>>
String s = "test string (67)";
System.out.println(s.substring(s.indexOf("(")+1,s.indexOf(")")));
Something like this:
public static String innerSubString(String txt, char prefix, char suffix) {
if(txt != null && txt.length() > 1) {
int start = 0, end = 0;
char token;
for(int i = 0; i < txt.length(); i++) {
token = txt.charAt(i);
if(token == prefix)
start = i;
else if(token == suffix)
end = i;
}
if(start + 1 < end)
return txt.substring(start+1, end);
}
return null;
}
This is a simple use \D+ regex and job done.
This select all chars except digits, no need to complicate
/\D+/
it will return original string if no match regex
var iAm67 = "test string (67)".replaceFirst("test string \\((.*)\\)", "$1");
add matches to the code
String str = "test string (67)";
String regx = "test string \\((.*)\\)";
if (str.matches(regx)) {
var iAm67 = str.replaceFirst(regx, "$1");
}
---EDIT---
i use https://www.freeformatter.com/java-regex-tester.html#ad-output to test regex.
turn out it's better to add ? after * for less match. something like this:
String str = "test string (67)(69)";
String regx1 = "test string \\((.*)\\).*";
String regx2 = "test string \\((.*?)\\).*";
String ans1 = str.replaceFirst(regx1, "$1");
String ans2 = str.replaceFirst(regx2, "$1");
System.out.println("ans1:"+ans1+"\nans2:"+ans2);
// ans1:67)(69
// ans2:67
String s = "(69)";
System.out.println(s.substring(s.lastIndexOf('(')+1,s.lastIndexOf(')')));
Little extension to top (MadProgrammer) answer
public static String getTextBetween(final String wholeString, final String str1, String str2){
String s = wholeString.substring(wholeString.indexOf(str1) + str1.length());
s = s.substring(0, s.indexOf(str2));
return s;
}
I have following String and i want to split this string into number of sub strings(by taking ',' as a delimeter) when its length reaches 36. Its not exactly splitting on 36'th position
String message = "This is some(sampletext), and has to be splited properly";
I want to get the output as two substrings follows:
1. 'This is some (sampletext)'
2. 'and has to be splited properly'
Thanks in advance.
A solution based on regex:
String s = "This is some sample text and has to be splited properly";
Pattern splitPattern = Pattern.compile(".{1,15}\\b");
Matcher m = splitPattern.matcher(s);
List<String> stringList = new ArrayList<String>();
while (m.find()) {
stringList.add(m.group(0).trim());
}
Update:
trim() can be droped by changing the pattern to end in space or end of string:
String s = "This is some sample text and has to be splited properly";
Pattern splitPattern = Pattern.compile("(.{1,15})\\b( |$)");
Matcher m = splitPattern.matcher(s);
List<String> stringList = new ArrayList<String>();
while (m.find()) {
stringList.add(m.group(1));
}
group(1) means that I only need the first part of the pattern (.{1,15}) as output.
.{1,15} - a sequence of any characters (".") with any length between 1 and 15 ({1,15})
\b - a word break (a non-character before of after any word)
( |$) - space or end of string
In addition I've added () surrounding .{1,15} so I can use it as a whole group (m.group(1)).
Depending on the desired result, this expression can be tweaked.
Update:
If you want to split message by comma only if it's length would be over 36, try the following expression:
Pattern splitPattern = Pattern.compile("(.{1,36})\\b(,|$)");
The best solution I can think of is to make a function that iterates through the string. In the function you could keep track of whitespace characters, and for each 16th position you could add a substring to a list based on the position of the last encountered whitespace. After it has found a substring, you start anew from the last encountered whitespace. Then you simply return the list of substrings.
Here's a tidy answer:
String message = "This is some sample text and has to be splited properly";
String[] temp = message.split("(?<=^.{1,16}) ");
String part1 = message.substring(0, message.length() - temp[temp.length - 1].length() - 1);
String part2 = message.substring(message.length() - temp[temp.length - 1].length());
This should work on all inputs, except when there are sequences of chars without whitespace longer than 16. It also creates the minimum amount of extra Strings by indexing into the original one.
public static void main(String[] args) throws IOException
{
String message = "This is some sample text and has to be splited properly";
List<String> result = new ArrayList<String>();
int start = 0;
while (start + 16 < message.length())
{
int end = start + 16;
while (!Character.isWhitespace(message.charAt(end--)));
result.add(message.substring(start, end + 1));
start = end + 2;
}
result.add(message.substring(start));
System.out.println(result);
}
If you have a simple text as the one you showed above (words separated by blank spaces) you can always think of StringTokenizer. Here's some simple code working for your case:
public static void main(String[] args) {
String message = "This is some sample text and has to be splited properly";
while (message.length() > 0) {
String token = "";
StringTokenizer st = new StringTokenizer(message);
while (st.hasMoreTokens()) {
String nt = st.nextToken();
String foo = "";
if (token.length()==0) {
foo = nt;
}
else {
foo = token + " " + nt;
}
if (foo.length() < 16)
token = foo;
else {
System.out.print("'" + token + "' ");
message = message.substring(token.length() + 1, message.length());
break;
}
if (!st.hasMoreTokens()) {
System.out.print("'" + token + "' ");
message = message.substring(token.length(), message.length());
}
}
}
}