Stringutils.isblank() vs String.isEmpty()

java

best-practices

java-8

string-manipulation

byNikita Barsukov·Jan 6, 2025

StringUtils.isBlank() checks for null, empty, or whitespace situations, while String.isEmpty() eyes only the empty state, blind to whitespace issues.

String misunderstood = "   ";
// Handles null, empty, and the dreaded phantom space scenario:
boolean unnoticed = StringUtils.isBlank(misunderstood); // true

// Only cares about an existential crisis:
boolean ignored = misunderstood.isEmpty(); // false, exists, but as space

Choose StringUtils.isBlank() for an in-depth interrogation; String.isEmpty() skips over those shifty whitespaces.

StringUtils.isBlank(): For when space isn't the final frontier

StringUtils.isBlank() acts like a null-friendly, space-sensitive guard dog that barks even when a string is a null or an elusive ghostly whitespace:

String nullValue;
// Won't let NullPointerException pass the guard post:
boolean checking = StringUtils.isBlank(nullValue); // true

It’s a warden on duty while validating user input to prevent processing full-of-nothing but whitespaces:

String sketchyInput = "   ";
boolean theJigIsUp = StringUtils.isBlank(sketchyInput); // true

And guess what, no more trimming sessions before doing the checks:

String sneakyTrim = "  I am sneaky  ";
// Trim the fat? Nah, StringUtils.isBlank() is a guilt-free method:
boolean uncovered = StringUtils.isBlank(sneakyTrim); // false

String.isEmpty(): When empty's all you care about

Sure, StringUtils.isBlank() seems like a one-size-fits-all lumberjack shirt, but String.isEmpty() still has its moments of glory:

Speedster

When speed trials are everything, and whitespace checking feels like extra weight, then embrace String.isEmpty() for its lightning-fast checks.

Literalist

When you must separate empty from whitespace, such as in a poetry slam, XML or JSON format:

String poeticWhitespace = "   ";
// Wants only confirmed emptiness, not metaphorical empty spaces:
boolean literalCheck = poeticWhitespace.isEmpty(); // false

The Unambiguous One

For the purist in you who appreciates clarity of thoughts and hates dealing with nulls and whitespaces:

String crispAndClear = "value";
// Clear as a bell, only empty strings will make a sound:
boolean positivelyNotEmpty = !crispAndClear.isEmpty(); // true

Code considerations and best practices

Off-the-shelf vs Custom

Do you stick to the Java standard or go fancy with third-party libraries like Apache Commons Lang? Judge based on your project's dependency footprint.

A bird in the hand...

Java continually evolves, so play catch-up. For instance, String.isBlank() was introduced in Java 11, which has similar prowess as StringUtils.isBlank().