1、Maven默认是源代码是src/main/java

    
         
         
     
      src/main/java 
           
         
     
      src/test/java
           
         
     
                
      
                     
       
        src/main/resources
                 
            
          
          
     
                
      
                      
       
        src/test/resources
                 
            
       
    

2、修改POM文件，形成多源代码

    
         
     
                
            
      
               
       
        org.codehaus.mojo
               
       
        build-helper-maven-plugin
               
       
        1.8
               
       
                  
        
                     
         
          add-source
                     
         
          generate-sources
                     
         
                        
          
           add-source
                      
                     
         
                        
          
                           
           src/java/main                
           src/java/generated              
                      
                   
                
             
           
      
    

3、项目结构