Extract string between two strings in java
JavaRegexStringJava Problem Overview
I try to get string between <%= and %>, here is my implementation:
String str = "ZZZZL <%= dsn %> AFFF <%= AFG %>";
Pattern pattern = Pattern.compile("<%=(.*?)%>");
String[] result = pattern.split(str);
System.out.println(Arrays.toString(result));
it return
[ZZZZL , AFFF ]
But my expectation is:
[ dsn , AFG ]
Where am i wrong and how to correct it ?
Java Solutions
Solution 1 - Java
Your pattern is fine. But you shouldn't be split()
ting it away, you should find()
it. Following code gives the output you are looking for:
String str = "ZZZZL <%= dsn %> AFFF <%= AFG %>";
Pattern pattern = Pattern.compile("<%=(.*?)%>", Pattern.DOTALL);
Matcher matcher = pattern.matcher(str);
while (matcher.find()) {
System.out.println(matcher.group(1));
}
Solution 2 - Java
I have answered this question here: https://stackoverflow.com/a/38238785/1773972
Basically use
StringUtils.substringBetween(str, "<%=", "%>");
This requirs using "Apache commons lang" library: https://mvnrepository.com/artifact/org.apache.commons/commons-lang3/3.4
This library has a lot of useful methods for working with string, you will really benefit from exploring this library in other areas of your java code !!!
Solution 3 - Java
Jlordo approach covers specific situation. If you try to build an abstract method out of it, you can face a difficulty to check if 'textFrom
' is before 'textTo
'. Otherwise method can return a match for some other occurance of 'textFrom
' in text.
Here is a ready-to-go abstract method that covers this disadvantage:
/**
* Get text between two strings. Passed limiting strings are not
* included into result.
*
* @param text Text to search in.
* @param textFrom Text to start cutting from (exclusive).
* @param textTo Text to stop cuutting at (exclusive).
*/
public static String getBetweenStrings(
String text,
String textFrom,
String textTo) {
String result = "";
// Cut the beginning of the text to not occasionally meet a
// 'textTo' value in it:
result =
text.substring(
text.indexOf(textFrom) + textFrom.length(),
text.length());
// Cut the excessive ending of the text:
result =
result.substring(
0,
result.indexOf(textTo));
return result;
}
Solution 4 - Java
Your regex looks correct, but you're splitting
with it instead of matching
with it. You want something like this:
// Untested code
Matcher matcher = Pattern.compile("<%=(.*?)%>").matcher(str);
while (matcher.find()) {
System.out.println(matcher.group());
}