Java logic code - Delete some text from a String

I want to remove any occurence of "is happy" sentence from a very large text ignoring case sensitivity. Here are some of that large text sentences :

1. "She is happy. I like that."

2. "His happy son"

3. "He is happy all the day"

4. "Tasha is Happy"

5. "Choose one of the following: is sad-is happy-is crying"

My initial code is :

String largeText = "....";  // The very large text her开发者_JS百科e.
String removeText = "is happy";
largeText = largeText.replaceAll( "(?i)" + removeText , "" ); 

This code will work fine with sentence number 1, 3, 4, 5. But i do not want to delete it from sentence number 2 as it has another meaning. How can i do that ?

Use \b around your pattern to detect word boundaries. ie:

String largeText = "....";  // The very large text here.
String removeText = "is happy";
largeText = largeText.replaceAll( "(?i)\\b" + removeText + "\\b" , "" ); 

You might want to look into atomic zero-width assertions -- patterns that match against positions inside a string (such as a word boundary), rather than text itself.

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java String.replaceAll regex question