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How to cast List<Object> to List

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时光取名叫无心
时光取名叫无心 2020-11-27 11:43

This does not compile, any suggestion appreciated.

 ...
  List list = getList();
  return (List) list;



Compil         


        
      
      
      

        

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                 天涯浪人 
              
              
    
                
                   天涯浪人
                                             
                
                
                (楼主)
            
              
                  
    
                2020-11-27 12:17
              
    

            
    
            
    
              
              

    As others have pointed out, you cannot savely cast them, since a List isn't a List. What you could do, is to define a view on the list that does in-place type checking. Using Google Collections that would be:
    


    return Lists.transform(list, new Function() {
  public Customer apply(Object from) {
    if (from instanceof Customer) {
      return (Customer)from;
    }
    return null; // or throw an exception, or do something else that makes sense.
  }
});

    
    
    
             
    
                                                        
    
            
            
    
              
                
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