?????????

• ?????????bean?????bean?????bean??????
• ???

  public class StudentA {
      private StudentB studentB;
      public StudentA(StudentB studentB) {
          this.studentB = studentB;
      }
  }
  public class StudentB {
      private StudentC studentC;
      public StudentB(StudentC studentC) {
          this.studentC = studentC;
      }
  }
  public class StudentC {
      private StudentA studentA;
      public StudentC(StudentA studentA) {
          this.studentA = studentA;
      }
  }

• ??????Spring???????????????

setter????????

• ??bean????field?setter????????bean?????bean??????
• ???

  public class StudentA {
      private StudentB studentB;
      public void setStudentB(StudentB studentB) {
          this.studentB = studentB;
      }
  }
  public class StudentB {
      private StudentC studentC;
      public void setStudentC(StudentC studentC) {
          this.studentC = studentC;
      }
  }
  public class StudentC {
      private StudentA studentA;
      public void setStudentA(StudentA studentA) {
          this.studentA = studentA;
      }
  }

• ?????????????Spring???????????????

?????????????

• Spring??????????????
  • singletonObjects???????????bean?
  • singletonFactories?????bean????
  • earlySingletonObjects??????????bean?

???????

• ??????????????????
• ???

• ?????????????????

?????????

• ????????????Spring???????????

?????????

• ?????Spring IDE?BeanFactoryUtils????????

???????

• ??????????bean???????????????

singletonObjects?

private final Map
    
      singletonObjects = new ConcurrentHashMap
     
      (256);
     
    

• ????????????bean?

singletonFactories?

private final Map
    
     > singletonFactories = new HashMap
     
      >(16);
     
    

• ??????bean????

earlySingletonObjects?

private final Map
    
      earlySingletonObjects = new HashMap
     
      (16);
     
    

• ???????????bean?

?????????

• ????????????????????????

???????

• ????bean???????????????

???????

• ????????????????bean????????

??????????

• ????????????????????????bean?