Java Reg Expression - java

I have a question that how can achieve the following using java regexp.
Consider my string say:
a = "activity=play, then I play cricket"
Here my requirement is,
if the above string "activity=play" then I should validate that string contains "cricket" as mentioned above.
if the above string contains "activity=noplay" then nothing should be present at the last of the string. (i.e. The above string should have cricket at the last).
How should I do it?

You do not need a regular expression if you just want to see if a string contains another string. You could do something like so:
String str = "...";
boolean isValid = false;
if(str.contains("activity=play"))
isValid = str.contains("cricket");
else if(str.contains("activity=noplay")
isValid = !str.contains("cricket")

String reg = "activity=play.*cricket";
String str = ".....";
boolean isValide = str.matches(reg);

Related

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;
}

split string and get the value using regex from a complicated string

I have a string like this {"product_tags":"yin_yang,yin yang"}.
what I want to do is just avoid everything else other than yin yang. There is two strings but I just want the first one.
Note that in some cases even if the second string is not available I want to get the same result. And that string might change so it is not necessary that the string will be always yin_yang sometimes it can be motorbike or anything else.
It Look like JSON String Use the JSONParser in java
JSONObject jobject=new JSONObject(STRING);
String value=jobject.getString("product_tags");
EDITED
Using REGEX
String json="{\"product_tags\":\"yin_yang,yin yang\"}";
json=json.replaceAll("([{}]+)", "");
String value[]=json.split(":");
System.out.print(value[1]);
You can use StringTokenizer to parse your string
String str ="{\"product_tags\":\"yin_yang,yin yang\"}";
StringTokenizer to = new StringTokenizer(str,":}");
while(to.hasMoreTokens()){
String firstString = (String) to.nextElement();
String secondString = (String) to.nextElement();
System.out.print(secondString);
}

Query regarding regular expression

hi I have a string like this:
String s = "#Path(\"/BankDBRestService/customerExist(String")\";
I want to make that string as
#Path("/BankDBRestService/customerExist")
I tried this:
String foo = s.replaceAll("[(](.*)", "");
i am getting output as
#Path
can anyone please provide me the reqular expression to make this work
Try this one :
String s = "#Path(\"/BankDBRestService/customerExist(String\")";
String res = s.replaceAll("[(]([a-zA-Z_])+", "");
System.out.println(res);
Output : #Path("/BankDBRestService/customerExist")
If your string is "#Path(\"/BankDBRestService/customerExist(String)\")" i.e. with closed parenthesis then use regex [(]([a-zA-Z_])+[)]
try this
String foo = s.replaceAll("(.*)\\(.*\\)", "$1");

Extract text from string 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.

android - search and replace in string java android

This is a part of a string
test="some text" test2="othertext"
It contains a lot more of similar text with same formating. Each "statment" is separate by empty space
How to search by name(test, test2) and replace its values(stuff between "")?
in java
I dont know if its clear enough but i dont know how else to explain it
I want to search for "test" and replace its content with something else
replace
test="some text" test2="othertext"
with something else
Edit:
This is a content of a file
test="some text" test2="othertext"
I read content of that file in a string
Now i want to replace some text with something else
some text is not static it can be anything
You can use the replace() method of String, which comes in 3 types and 4 variants:
revStr.replace(oldChar, newChar)
revStr.replace(target, replacement)
revStr.replaceAll(regex, replacement)
revStr.replaceFirst(regex, replacement)
Eg:
String myString = "Here is the home of the home of the Stars";
myString = myString.replace("home","heaven");
///////////////////// Edited Part //////////////////////////////////////
String s = "The quick brown fox test =\"jumped over\" the \"lazy\" dog";
String lastStr = new String();
String t = new String();
Pattern pat = Pattern.compile("test\\s*=\\s*\".*\"");
Matcher mat = pat.matcher(s);
while (mat.find()) {
// arL.add(mat.group());
lastStr = mat.group();
}
Pattern pat1 = Pattern.compile("\".*\"");
Matcher mat1 = pat1.matcher(lastStr);
while (mat1.find()) {
t = mat.replaceAll("test=" + "\"Hello\"");
}
System.out.println(t);
So you want to replace every instance of "test" with something else?
Let's say the string name is myString:
myString = myString.replace("test","something else");
Is this what you are looking to do?
I think you are asking that you fetch data from file in the form of string,
lets suppose, your string is,
String s = "My name="sahil" and my company="microsoft", also i live in
country="india"".
Now you want to replace "sahil" with "mahajan" and "microsoft" with "google".
I have tried experimenting with the string methods to implement this functionality, but didnt find a relavent result. But i could provide you with some methods. You could use regionMatches, indexOf("name=""). But these functions will help you in finding where sahil(suppose) is located. but the replcae function here is difficult to work, because it replaces character sequence, for which you should know the exact character sequence.
Now you might try experimenting with the string methods. It could help.
I haven't tested this, but it should work:
String mFileContents;
private void replaceValue(String name, String newValue) {
int nameIndex = mFileContents.indexOf(name);
int equalSignIndex = mFileContents.indexOf("=", nameIndex);
int oldValueIndex = equalSignIndex + 2;
int oldValueLength = mFileContents.indexOf("\"", oldValueIndex);
String oldValue = mFileContents.substring(oldValueIndex, oldValueLength);
String firstHalf = mFileContents.substring(0, oldValueIndex -1);
String secondHalf = mFileContents.substring(oldValueIndex);
secondHalf.replaceFirst(oldValue, newValue);
mFileContents = firstHalf + secondHalf;
}
String a = "some text";
a = a.replace("text", "inserted value");
System.out.print(a);
Try this

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