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Java String Trim

Emma Brown
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#java #programming #java-programming
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String cleanup challenge: `trim()` and `replaceAll()` fail. How do you efficiently remove *only* the spaces between key-value pairs? Solve this elegant regex puzzle!

How can I remove only whitespace *within* a string (e.g., "name=john age=13 year=2001") without removing characters like "="? `trim()` and `replaceAll("\\s", "")` are insufficient.

Solution in a Nutshell

Java offers several ways to remove whitespace from strings. For Spring Boot developers, understanding these options is crucial for data sanitization and efficient string manipulation.

Methods:

  • trim(): Removes leading and trailing whitespace.
String str = "  Hello World  ";
String trimmed = str.trim(); // "Hello World"
  • replaceAll() (Regex): Removes all whitespace (spaces, tabs, newlines).
String str = "  Hello\tWorld\n ";
String noWhitespace = str.replaceAll("\\s+", ""); // "HelloWorld"
  • replace() (Specific Character): Removes only specific whitespace characters (e.g., spaces). Less efficient for multiple whitespace types.
String str = "  Hello World  ";
String noSpaces = str.replace(" ", ""); // "HelloWorld"

Choosing the right method:

  • Use trim() for simple leading/trailing whitespace removal.
  • Use replaceAll("\\s+", "") for comprehensive whitespace removal.
  • Use replace() only if you need to remove specific whitespace characters and performance isn't critical.

Spring Boot Context: These methods are directly applicable within Spring Boot applications, often used in controllers, services, or repositories for data preprocessing before persistence or display. Remember to handle potential NullPointerExceptions by checking for null values before calling these methods.