??????????Java???????I??????????????????????????????????????????????д?????????????????????????÷??????????????????????????д?????????????????е??????????????????????????????????
?????????????????????????ж???????о??????????????????google????????????????:
??????????????????????????????????(????????)????????????java??????????????????????????????????????????
?????????????????????京????????
???????????????????????????????????а????????????????????????????????Щ?????????????????ж???????????????????????????????????????????????????????????????????????????????????飬??????????????塣????????????????????????????????????????????????????????????????????а????Щ??????????????
???????????????
???????????????????????????????
??????????????????????
???????÷?????
????????????????????????????????????????????????????????????????????????е??????????????????????????????????????java????????????????????????????????????????java???е???????final??static??private???????????????
????????????????????????????????
??????1????????????????????????????????????
??????2?????private??static??final???ε???????????????t?????????鷽???????????????д?????????????????????????ж??????
??????3??????????????????????????????????????????????ɡ?
??????4??????(Overload)???????t????????????д(Override)????????????????ɡ?
???????濪?????????
????public class Test {
????public static void main(String[] args) {
????String str = new String();
????Lee lee = new Lee();
????lee.say(str);
????}
????static class Lee {
????public void say(Object obj) {
????System.out.println("?????Object");
????}  
????public void say(String str) {
????System.out.println("?????String");
????}
????}
????}
??????н????
????$ java Test
?????????String
???????????????У?lee?????????????????????????????Object?????????????????????????????String???????????????????str?????String???????н???String?????????call?????????á???????????????????????????????е???????
???????????????????????:
????javap -c Test   
????Compiled from "Test.java"
????public class CoreJava.day_2.Test {
????public CoreJava.day_2.Test();
????Code:
????0: aload_0
????1: invokespecial #1                  // Method java/lang/Object."<init>":()V
????4: return
????public static void main(java.lang.String[]);
????Code:
????0: new           #2                  // class java/lang/String
????3: dup
????4: invokespecial #3                  // Method java/lang/String."<init>":()V
????7: astore_1
????8: new           #4                  // class CoreJava/day_2/Test$Lee
????11: dup
????12: invokespecial #5                  // Method CoreJava/day_2/Test$Lee."<init>":()V
????15: astore_2
????16: aload_2
????17: aload_1
????18: invokevirtual #6                  // Method CoreJava/day_2/Test$Lee.call:(Ljava/lang/String;)V
????21: return
????}
???????????????18: invokevirtual #6 // Method CoreJava/day_2/Test$Lee.call:(Ljava/lang/String;)V????????????????????????????String?????????????say??????
????????????д??￡?
????public class Test{
????public static void main(String[] args) {
????String str = new String();
????Lee lee = new SecLee();
????lee.say(str);
????}
????static class Lee {
????public void say(String str) {
????System.out.println("?????String");
????}
????}
????static class SecLee extends Lee {
????@Override
????public void say(String str) {
????System.out.println("?????????String");
????}
????}
????}
??????????
????$ java Test
?????????????String
???????棬??SecLee?????Lee????????д??say???????????????????Lee????????lee???????????????????????????SecLee????????????????????????SecLee??say??????????????Lee??say?????????????????????????????????????????????????????????????????????汾??say????????