Comparing Java's Scanner, StringTokenizer, and String.split: Which Should You Use?

What are the differences between Java's Scanner, StringTokenizer, and String.split methods, and when should each be used?

Java offers different tools for splitting strings: Scanner, StringTokenizer, and String.split. Each has its strengths and specific use cases, making them suitable for various scenarios when parsing text data.

String input = "Java,Scanner,StringTokenizer,String.split";
String[] tokens = input.split(",");
for(String token : tokens) {
    System.out.println(token);
} // Outputs each string separated by commas.

Causes

• Scanner provides a more versatile and object-oriented approach for parsing different input types (not just strings), making it suitable for handling complex inputs.
• StringTokenizer is an older class that offers a simple mechanism to split strings, but lacks modern features and flexibility compared to Scanner.
• String.split() is straightforward but may have performance drawbacks with large datasets or input strings, as it creates an array and uses regex for splitting.

Solutions

• Use Scanner for reading data from various sources (files, input streams, etc.) and applying tokenized parsing.
• Prefer StringTokenizer when you need a lightweight method for simple string splitting and don't require advanced capabilities.
• Utilize String.split() when you want to use regular expressions for complex delimiters or need a quick way to separate strings.

Mistake: Confusing Scanner's use for numeric and string parsing without understanding its context.

Solution: Remember that Scanner can parse different data types and is especially useful for formatted input.

Mistake: Using StringTokenizer when Scanner would provide better readability or flexibility, especially for modern applications.

Solution: Consider adopting Scanner for its enhanced functionality and better paradigms of parsing.

Mistake: Overlooking performance implications of String.split() due to regex evaluation.

Solution: For high-performance applications, evaluate if Scanner or StringTokenizer can be a better fit.