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'ThreadLocal.set()' with null as an argument

Reports java.lang.ThreadLocal.set() with null as an argument.

This call does not free the resources, and it may cause a memory leak.

It may happen because:

  • Firstly, ThreadLocal.set(null) finds a map associated with the current Thread. If there is no such a map, it will be created

  • It sets key and value: map.set(this, value), where this refers to instance of ThreadLocal

java.lang.ThreadLocal.remove() should be used to free the resources.

Example:

ThreadLocal<Integer> threadLocal = new ThreadLocal<>(); threadLocal.set(null);

After the quick-fix is applied:

threadLocal.remove();

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.

ThreadLocalSetWithNull
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 | Threading issues

New in 2023.2

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