当基类需要捕获异常时，在派生类构造函数中使用超 [英] Using Super in a Derived Class Constructor When Base Class Requires Exceptions to be Caught

问题描述

我想在Java中将类B派生为新的类C.基类构造函数要求必须抛出或捕获未报告的异常。但是如果我尝试把super（..）放在一个try / catch，然后我被告知调用super必须是构造函数中的第一个语句。

 公共类C扩展B 
 {
 //后续尝试在构造函数生成错误Undeclared exception E;必须被捕获或声明
 //被抛出
 public C（String s）
 {
 super（s）; 
} 
 
 //但下面的例子也失败，因为调用super必须是构造函数中的第一个语句
 public C（String s）
 {
 try 
 {
 super（s）; 
} 
 catch（Exception e）
 {
} 
} 
} 
  
 
 
 
非常感谢，
 Chris 
解决方案
您可以随时使用throws子句声明构造函数签名中的异常。
  public C（String s）throws WhatEverException 
 {
  
I'm trying to derive a class B to a new class C in Java.  The base class constructor requires that unreported exceptions must be thrown or caught.  But if I try to put super(..) inside a try/catch then I'm told that the call to super must be the first statement in the constructor.  Does anyone know a way around this?
public class C extends B
{
   //Following attempt at a constructor generates the error "Undeclared exception E; must be caught or declared
   //to be thrown
    public C(String s)
    { 
         super(s);
    }

    //But the below also fails because "Call to super must be the first statement in constructor"
    public C(String s)
    {
         try
         {
              super(s);
         }
          catch( Exception e)
         {
         }
     }
 }
Many thanks,
Chris
解决方案
You can always declare the Exception in constructor signature using throws clause. 
public C(String s) throws WhatEverException
    {


                        
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