Extract text from string Java - java

With this string "ADACADABRA". how to extract "CADA" From string "ADACADABRA" in java.
and also how to extract the id between "/" and "?" from the link below.
http://www.youtube-nocookie.com/embed/zaaU9lJ34c5?rel=0
output should be: zaaU9lJ34c5
but should use "/" and "?" in the process.


and also how to extract the id between "/" and "?" from the link below.
http://www.youtube-nocookie.com/embed/zaaU9lJ34c5?rel=0
output should be: zaaU9lJ34c5
Should be :
String url = "http://www.youtube-nocookie.com/embed/zaaU9lJ34c5?rel=0";
String str = url.substring(url.lastIndexOf("/") + 1, url.indexOf("?"));


String s = "ADACADABRA";
String s2 = s.substring(3,7);
Here 3 specifies the beginning index, and 7 specifies the stopping point.
The string returned contains all the characters from the beginning index, up to, but not including, the ending index.


I'm not entirely sure what you mean by extract, so I've provided the code to remove it from the String, I'm not certain if this is what you want.
public static void main (String args[]){
String string = "ADACADABRA";
string = string.replace("CADA", "");
System.out.println(string);
}


This is untested but something like this may help for the youtube part:
String youtubeUrl = "http://www.youtube-nocookie.com/embed/zaaU9lJ34c5?rel=0";
String[] urlParts = youtubeUrl.split("/");
String videoId = urlParts[urlParts.length - 1];
videoId = videoId.substring(0, videoId.indexOf("?"));
Extracting CADA from the string makes no sense. You will need to specify how you have determined that CADA is the string to extract.
E.g. is it because it is the middle 4 characters? Is it because you are stripping off 3 characters each side? Are you just looking for the String "CADA"? Is it characters 3,7 of the String? Is it the first 4 of the last 7 characters of a String? Is it because it contains 2 vowels and 2 consanants? I could go on..


String regex = "CADA";
Pattern p = Pattern.compile(regex, Pattern.MULTILINE);
Matcher m = p.matcher(originalText);
while (m.find()) {
String outputThis = m.group(1);
}
Use this tool http://www.regexplanet.com/advanced/java/index.html


Probably, you don't take in account the fact of java.lang.String immutability. That's why you need to assign the result of substringing to a new variable.

Related

Remove parts of String? [duplicate]

I want to remove a part of string from one character, that is:
Source string:
manchester united (with nice players)
Target string:
manchester united

There are multiple ways to do it. If you have the string which you want to replace you can use the replace or replaceAll methods of the String class. If you are looking to replace a substring you can get the substring using the substring API.
For example
String str = "manchester united (with nice players)";
System.out.println(str.replace("(with nice players)", ""));
int index = str.indexOf("(");
System.out.println(str.substring(0, index));
To replace content within "()" you can use:
int startIndex = str.indexOf("(");
int endIndex = str.indexOf(")");
String replacement = "I AM JUST A REPLACEMENT";
String toBeReplaced = str.substring(startIndex + 1, endIndex);
System.out.println(str.replace(toBeReplaced, replacement));

String Replace
String s = "manchester united (with nice players)";
s = s.replace(" (with nice players)", "");
Edit:
By Index
s = s.substring(0, s.indexOf("(") - 1);

Use String.Replace():
http://www.daniweb.com/software-development/java/threads/73139
Example:
String original = "manchester united (with nice players)";
String newString = original.replace(" (with nice players)","");

originalString.replaceFirst("[(].*?[)]", "");
https://ideone.com/jsZhSC
replaceFirst() can be replaced by replaceAll()

Using StringBuilder, you can replace the following way.
StringBuilder str = new StringBuilder("manchester united (with nice players)");
int startIdx = str.indexOf("(");
int endIdx = str.indexOf(")");
str.replace(++startIdx, endIdx, "");

You should use the substring() method of String object.
Here is an example code:
Assumption: I am assuming here that you want to retrieve the string till the first parenthesis
String strTest = "manchester united(with nice players)";
/*Get the substring from the original string, with starting index 0, and ending index as position of th first parenthesis - 1 */
String strSub = strTest.subString(0,strTest.getIndex("(")-1);

I would at first split the original string into an array of String with a token " (" and the String at position 0 of the output array is what you would like to have.
String[] output = originalString.split(" (");
String result = output[0];

Using StringUtils from commons lang
A null source string will return null. An empty ("") source string will return the empty string. A null remove string will return the source string. An empty ("") remove string will return the source string.
String str = StringUtils.remove("Test remove", "remove");
System.out.println(str);
//result will be "Test"

If you just need to remove everything after the "(", try this. Does nothing if no parentheses.
StringUtils.substringBefore(str, "(");
If there may be content after the end parentheses, try this.
String toRemove = StringUtils.substringBetween(str, "(", ")");
String result = StringUtils.remove(str, "(" + toRemove + ")");
To remove end spaces, use str.trim()
Apache StringUtils functions are null-, empty-, and no match- safe

Kotlin Solution
If you are removing a specific string from the end, use removeSuffix (Documentation)
var text = "one(two"
text = text.removeSuffix("(two") // "one"
If the suffix does not exist in the string, it just returns the original
var text = "one(three"
text = text.removeSuffix("(two") // "one(three"
If you want to remove after a character, use
// Each results in "one"
text = text.replaceAfter("(", "").dropLast(1) // You should check char is present before `dropLast`
// or
text = text.removeRange(text.indexOf("("), text.length)
// or
text = text.replaceRange(text.indexOf("("), text.length, "")
You can also check out removePrefix, removeRange, removeSurrounding, and replaceAfterLast which are similar
The Full List is here: (Documentation)

// Java program to remove a substring from a string
public class RemoveSubString {
public static void main(String[] args) {
String master = "1,2,3,4,5";
String to_remove="3,";
String new_string = master.replace(to_remove, "");
// the above line replaces the t_remove string with blank string in master
System.out.println(master);
System.out.println(new_string);
}
}

You could use replace to fix your string. The following will return everything before a "(" and also strip all leading and trailing whitespace. If the string starts with a "(" it will just leave it as is.
str = "manchester united (with nice players)"
matched = str.match(/.*(?=\()/)
str.replace(matched[0].strip) if matched

Parse string value from URL

I have a string (which is an URL) in this pattern https://xxx.kflslfsk.com/kjjfkskfjksf/v1/files/media/93939393hhs8.jpeg
now I want to clip it to this
media/93939393hhs8.jpeg
I want to remove all the characters before the second last slash /.
i'm a newbie in java but in swift (iOS) this is how we do this:
if let url = NSURL(string:"https://xxx.kflslfsk.com/kjjfkskfjksf/v1/files/media/93939393hhs8.jpeg"), pathComponents = url.pathComponents {
let trimmedString = pathComponents.suffix(2).joinWithSeparator("/")
print(trimmedString) // "output = media/93939393hhs8.jpeg"
}
Basically, I'm removing everything from this Url expect of last 2 item and then.
I'm joining those 2 items using /.

String ret = url.substring(url.indexof("media"),url.indexof("jpg"))

Are you familiar with Regex? Try to use this Regex (explained in the link) that captures the last 2 items separated with /:
.*?\/([^\/]+?\/[^\/]+?$)
Here is the example in Java (don't forget the escaping with \\:
Pattern p = Pattern.compile("^.*?\\/([^\\/]+?\\/[^\\/]+?$)");
Matcher m = p.matcher(string);
if (m.find()) {
System.out.println(m.group(1));
}
Alternatively there is the split(..) function, however I recommend you the way above. (Finally concatenate separated strings correctly with StringBuilder).
String part[] = string.split("/");
int l = part.length;
StringBuilder sb = new StringBuilder();
String result = sb.append(part[l-2]).append("/").append(part[l-1]).toString();
Both giving the same result: media/93939393hhs8.jpeg

string result=url.substring(url.substring(0,url.lastIndexOf('/')).lastIndexOf('/'));
or
Use Split and add last 2 items
string[] arr=url.split("/");
string result= arr[arr.length-2]+"/"+arr[arr.length-1]

public static String parseUrl(String str) {
return (str.lastIndexOf("/") > 0) ? str.substring(1+(str.substring(0,str.lastIndexOf("/")).lastIndexOf("/"))) : str;
}

Check if id in string and get value if so

I am trying to get a regex to match, then get the value with it. For example, I want to check for 1234 as an id and if present, get the status (which is 0 in this case). Basically its id:status. Here is what I am trying:
String topicStatus = "1234:0,567:1,89:2";
String someId = "1234";
String regex = "\\b"+someId+":[0-2]\\b";
if (topicStatus.matches(regex)) {
//How to get status?
}
Not only do I not know how to get the status without splitting and looping through, I don't know why it doesn't match the regex.
Any help would be appreciated. Thanks.

Use the Pattern class
String topicStatus = "1234:0,567:1,89:2";
String someId = "1234";
String regex = "\\b"+someId+":[0-2]\\b";
Pattern MY_PATTERN = Pattern.compile(regex);
Matcher m = MY_PATTERN.matcher(topicStatus);
while (m.find()) {
String s = m.group(1);
System.out.println(s);
}
The key here is to surround the position you want [0-2] in parenthesis which means it will be saved as the first group. You then access it through group(1)

I made some assumptions that your pairs we're always comma separate and then delimited by a colon. Using that I just used split.
String[] idsToCheck = topicStatus.split(",");
for(String idPair : idsToCheck)
{
String[] idPairArray = idPair.split(":");
if(idPairArray[0].equals(someId))
{
System.out.println("id : " + idPairArray[0]);
System.out.println("status: " + idPairArray[1]);
}
}

Parsing String and Int in java

Im using java and I have a String that I would like to parse which contains the following
Logging v0.12.4
and would like to split it into a String containing
Logging
and an integer array containing
0.12.4
where
array[i][0] = 0
and
array[i][1] = 12
and so on. I have been stuck on this for a while now.

split your string on space to get Logging and v0.12.4
remove (substring) v from v0.12.4
split 0.12.4 on dot (use split("\\.") since dot is special in regex)
you can also parse each "0" "12" "4" to integer (Integer.parseInt can be helpful).

You can use a regex or just normal String splitting
String myString = "Logging v0.12.4";
String[] parts = myString.split(" v");
// now parts[0] will be "Logging" and
// parts[1] will be "0.12.4";
Then do the same for the version part:
String[] versionParts = parts[1].split("\\.");
// versionParts[0] will be "0"
// versionParts[1] will be "12"
// versionParts[2] will be "4"
You can "convert" these to integers by using Integer.parseInt(...)

Here ya go buddy, because I'm feeling generous today:
String string = "Logging v0.12.4";
Matcher matcher = Pattern.compile("(.+?)\\s+v(.*)").matcher(string);
if (matcher.matches()) {
String name = matcher.group(1);
int[] versions = Arrays.stream(matcher.group(2).split("\\.")).mapToInt(Integer::parseInt).toArray();
}

Using regular expressions to rename a string

In java, I want to rename a String so it always ends with ".mp4"
Suppose we have an encoded link, looking as follows:
String link = www.somehost.com/linkthatIneed.mp4?e=13974etc...
So, how do I rename the link String so it always ends with ".mp4"?
link = www.somehost.com/linkthatIneed.mp4 <--- that's what I need the final String to be.

Just get the string until the .mp4 part using the following regex:
^(.*\.mp4)
and the first captured group is what you want.
Demo: http://regex101.com/r/zQ6tO5

Another way to do this would be to split the string with ".mp4" as a split char and then add it again :)
Something like :
String splitChar = ".mp4";
String link = "www.somehost.com/linkthatIneed.mp4?e=13974etcrezkhjk"
String finalStr = link.split(splitChar)[0] + splitChar;
easy to do ^^
PS: I prefer to pass by regex but it ask for more knowledge about regex ^^

Well you can also do this:
Match the string with the below regex
\?.*
and replace it with empty string.
Demo: http://regex101.com/r/iV1cZ8

Try below code,
private String trimStringAfterOccurance(String link, String occuranceString) {
Integer occuranceIndex = link.indexOf(occuranceString);
String trimmedString = (String) link.subSequence(0, occuranceIndex + occuranceString.length() );
System.out.println(trimmedString);
return trimmedString;
}

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