如何在對象之間傳遞數據

Question

我想傳遞類之間的一些信息，如成功或失敗，失敗的原因，缺失的數據等 但我不知道哪個是正確的方式來做到這一點。此外，我無法將信息作爲參數傳遞，因爲我需要將其恢復。由於已有返回值，因此無法返回任何值。 例如：假設我有類這樣的（它只是啞代碼的實際代碼很長）

class A { 
    B b = new B(); 
    C c = new C(); 
    b.putData(); 
    c.putData(); 

    //Want to print all the inforamtion of what happend 
    //in methods of putData and getData. How to do that? 
} 

class B { 

    boolean putData() { 
     D d = new D(); 
     Data data =d.getData(); 
     //some code goes here 
    } 
} 
Class C{ 
    boolean putData() { 
     //some code here 
    } 
} 

Answer 1

看看下面的代碼可以幫助你。

class A { 
    B b = new B(); 
    C c = new C(); 
    String resultClassB = b.putData(); 
    String resultClassC = c.putData(); 

    System.out.println(resultClassB); 
    System.out.println(resultClassC) 

    //Want to print all the inforamtion of what happend 
//in methods of putData and getData. How to do that? 
} 

class B { 

    String putData() { 
    D d = new D(); 
    String data =d.getData(); 
    //some code goes here 

    return data' 

} 

} 
Class C { 
    String putData() { 
    //some code here 
    String result = "reason for failure and success"; 
    return result' 
    } 
} 

class Data(){ 
    String getData(){ 
     String data = "get all data to print using some logic"; 
     return data; 
    } 
} 

Answer 2

您可以使用try {} catch（Exception）{}在出現問題時獲取信息。

Succes將是一個有效的返回對象。

class A { 
      B b = new B(); 
      C c = new C(); 
      b.putData(); 
      try 
      { 
       c.putData(); 
      } 
      catch(Exception e) 
      { 
       //do error handling, or print stacktrace 
      } 

      //Want to print all the inforamtion of what happend 
     //in methods of putData and getData. How to do that? 
     } 

    class B { 

     boolean putData() { 
      D d = new D(); 
      Data data =d.getData(); 
      //some code goes here 
     } 
    } 
     Class C{ 
     boolean putData() throws Exception{ 
      if(<data_missing>) throw new Exception("Data missing"); 
     } 
}