An instance initializer may be static if it does not reference any of its class' non-static members. Static initializers are executed once when the class is resolved, while instance initializers are executed on each instantiation of the class.

This inspection doesn't report instance empty initializers and initializers in anonymous classes.

Example:

  class A {
     public static String CONSTANT;
     {
        CONSTANT = "Hello";
     }
  }

After the quick-fix is applied:

  class A {
     public static String CONSTANT;
     static {
        CONSTANT = "Hello"; //now initialized only once per class
     }
  }