Overview

Some Methods

ArrayUtils.nullToEmpty(…)

String[] names = null;

When iterating over the array without a check, we get a java.lang.NullPointerException:

for (String string : names) {
// ....
}

We can check the array with an if statement:

if (names != null) {
  for (String string : names) {
    // ...
  }
}

Or we can use the ArrayUtils.nullToEmpty(...) method inside the for statement:

for (String string : ArrayUtils.nullToEmpty(names)) {
}

With the use of ArrayUtils.nullToEmpty(...) instead of the if check, the complexity of the method is reduced (no extra execution branch) and you have to write less tests.

Test for empty

• isEmpty
• isNotEmpty

Add and remove elements

• add
• addAll
• remove
• removeAll
• removeElement

References

http://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/ArrayUtils.html