Non-thread-safe 'static' field access

Reports access to static fields that are of a non-thread-safe type.

When a static field is accessed from an instance method or a non-synchronized block, multiple threads can access that field. This can lead to unspecified side effects, like exceptions and incorrect results.

Example:

  class Sample {
    private static final SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
    String method() {
      return df.format("");
    }
  }

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.

AccessToNonThreadSafeStaticField

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

You can specify which types should be considered not thread-safe. Only fields with these exact types or initialized with these exact types are reported, because there may exist thread-safe subclasses of these types.

Inspection options

Here you can find the description of settings available for the Non-thread-safe 'static' field access inspection, and the reference of their default values.

Non-thread-safe classes: Default value:
[java.text.Format, java.text.DateFormat, java.text.SimpleDateFormat, java.text.MessageFormat, java.text.DecimalFormat, java.text.ChoiceFormat, java.util.Calendar]

Suppressing Inspection

You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:

//noinspection AccessToNonThreadSafeStaticField

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

IntelliJ IDEA 2025.2

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.2, Qodana for JVM 2025.2,

Last modified: 18 September 2025