发表新帖
发表新帖

bad return type in lambda expression

后端 未结
关注
2 1135
情深已故
情深已故 2021-02-05 14:00

The following code compiles fine in IntelliJ and Eclipse, but the JDK compiler 1.8.0_25 complains. First, the code.

import java.util.function.Predicate;

public
2条回答
  • 无人及你
    无人及你 (楼主)
    2021-02-05 14:17

    includes Object, which isn't a Boolean. ie 

    MyPredicate

    Could be a 

    MyPredicate



    and you can't return an Object as a boolean.
    


    Try changing your lambda to:
    


    MyStream. create().filter(b -> Boolean.TRUE.equals(b));

    


    which will compile and execute without error not matter the type of the stream, but will return true for elements that are true Boolean values.
    
    
    
             
    
                                                        
    
            
            
    
              
                
                0
              
                   
                
               讨论(0)
              
                                                  
              
              
    
                          
             
       
          
              
    
                                       
    

    

                
    
                         
          
                              			
        
        
        
    
          
    
            
            
    
              
              
    
            
    


                                 
              
    
            
    
                          
    

        
         
    
                
                
    
                  
                
    
                
    
                   看不清?
                
    
              
    
                                  
    
                    
   
                 
             
              
    提交回复
    
            
    
          
    
        
    
      
       
      
    
    
    
          
 
     
 
    
        
    热议问题