switch case 配合 enum 还会生成一个匿名内部类呢？

//: enumerated/TrafficLight.java
// Enums in switch statements.
import static net.mindview.util.Print.*;

// Define an enum type:
enum Signal { GREEN, YELLOW, RED, }

public class TrafficLight {
    Signal color = Signal.RED;
    public void change() {
        switch(color) {
            // Note that you don't have to say Signal.RED
            // in the case statement:
            case RED:    color = Signal.GREEN;
                break;
            case GREEN:  color = Signal.YELLOW;
                break;
            case YELLOW: color = Signal.RED;
                break;
        }
    }
    public String toString() {
        return "The traffic light is " + color;
    }
    public static void main(String[] args) {
        TrafficLight t = new TrafficLight();
        for(int i = 0; i < 7; i++) {
            print(t);
            t.change();
        }
    }
} 

这是一个来自 java 编程思想的代码，我发现 out 目录还生成了一个 TrafficLight$1.class，意思生成了一个匿名内部类呢，这是因为 switchcase 吗？

TrafficLight.class 部分汇编如下：

  public void change();
   Code:
      0: getstatic     #4                  // Field TrafficLight$1.$SwitchMap$Signal:[I  这里去得到匿名内部类的静态成员
      3: aload_0
      4: getfield      #3                  // Field color:LSignal;
      7: invokevirtual #5                  // Method Signal.ordinal:()I
     10: iaload
     11: tableswitch   { // 1 to 3
                    1: 36
                    2: 46
                    3: 56
              default: 63
         }

TrafficLight$1.class 部分汇编如下：

class TrafficLight$1 {
 static final int[] $SwitchMap$Signal;  静态成员是个 int 数组

 static {};
   Code:
      0: invokestatic  #1                  // Method Signal.values:()[LSignal;
      3: arraylength
      4: newarray       int
      6: putstatic     #2                  // Field $SwitchMap$Signal:[I  为啥这里只有一个 putstatic，之后又三个 getstatic Field $SwitchMap$Signal:[I 呀？
      9: getstatic     #2                  // Field $SwitchMap$Signal:[I
     12: getstatic     #3                  // Field Signal.RED:LSignal;
     15: invokevirtual #4                  // Method Signal.ordinal:()I
     18: iconst_1
     19: iastore
     20: goto          24
     23: astore_0
     24: getstatic     #2                  // Field $SwitchMap$Signal:[I
     27: getstatic     #6                  // Field Signal.GREEN:LSignal;
     30: invokevirtual #4                  // Method Signal.ordinal:()I
     33: iconst_2
     34: iastore
     35: goto          39
     38: astore_0
     39: getstatic     #2                  // Field $SwitchMap$Signal:[I
     42: getstatic     #7                  // Field Signal.YELLOW:LSignal;
     45: invokevirtual #4                  // Method Signal.ordinal:()I