Syntax of switch Statement (see Java Language Specification, section 13.9)
does not allow using statements without 'case' in switch block:

        SwitchStatement:
            switch ( Expression ) SwitchBlock

        SwitchBlock:
            { SwitchBlockStatements_opt }

        SwitchBlockStatements:
             SwitchBlockStatement
             SwitchBlockStatements SwitchBlockStatement
      
        SwitchBlockStatement:
             SwitchLabels BlockStatements

        SwitchLabels
             SwitchLabel
             SwitchLabels SwitchLabel

        SwitchLabel
             case ConstantExpression :
             default :


But Java compiler don't consider this as an error and
compiles such switch statement successfully.
See example below:

> cat stmt107.java
public class stmt107
{
  public static void main(String args[])
  {
     int b = 2;
     for ( b = 1; b < 4; b++ )
     {
        switch ( b )
        {
              System.out.println("nothing");
        }
        System.out.println("PASS " + b);
     }
  }
}


    
> /usr/local/java/1.0/bin/javac stmt107.java
> /usr/local/java/1.0/bin/java stmt107
PASS 1
PASS 2
PASS 3
>