'String.equals()' can be replaced with 'String.isEmpty()'

Reports equals() being called to compare a String with an empty string. In this case, using .isEmpty() is better as it shows you exactly what you're checking.

Example:

  void checkString(String s){
    if ("".equals(s)) throw new IllegalArgumentException();
  }

After the quick-fix is applied:

  void checkString(String s){
    if (s != null && s.isEmpty()) throw new IllegalArgumentException();
  }

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

StringEqualsEmptyString

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | Java | Performance

"".equals(str) returns false when str is null. For safety, this inspection's quick-fix inserts an explicit null-check when the equals() argument is nullable. Use the option to make the inspection ignore such cases.

Inspection options

Here you can find the description of settings available for the 'String.equals()' can be replaced with 'String.isEmpty()' inspection, and the reference of their default values.

Do not report when null-check could be necessary: Default: Selected

Availability

By default bundled with: IntelliJ IDEA 2024.1, Qodana for JVM 2024.1,
Can be installed with plugin: Java, 241.18072

Last modified: 18 June 2024