https://docs.oracle.com/javase/specs/jls/se7/html/jls-8.html#jls-8.3.2.3 Workaround: Class SomeClass{     static {         Thread t1 = new Thread(new Runnable() {             @Override                 public void run() {                 System.out.println(abc); //works             }         });         Thread t2 = new Thread(() -> {             System.out.println(SomeClass.abc);             //                 ^-- now works         });         t1.start();         t2.start();     }     private static String abc = "test"; //declare after static block     public static void main(String args[]) {         System.out.println("main：" + DataAnalyseTest.abc);     } }