Re: Groovy and Grails vs. Java for Web Interface (see Java web application frameworks / architecture)

Kenneth P. Turvey wrote:


I see your point. But there's also a philosophical difference.

A Java app tends to be more n-tier. In your Groovy example you specify an
amount of detail that a Java app would leave in the database, i.e., the DDL.
The @Column annotation has an attribute 'columnDefinition' that lets you plug
in most of that stuff with SQL syntax, but you normally wouldn't go that way.

I also think that people worship "succinct" too much. Terse can be hard to
read, and collapsed into a single tier can become unwieldy quite quickly.

There's a state-space rationale for layering and decoupling applications.

Spinning from the Groovy example:

Please do not use TAB characters to indent Usenet posts.


Here's a way to do this in Java. It isn't exactly the same, of course. I
transfigured from the Groovy idiomatically rather than literally to show how
one might normally do it in Java. If anything I'm putting in more detail than
you'd want to in a Java entity.

Java would more verbosely put business rules either into entity validation
logic within setX() methods, or in a separate business-rule layer. The
verbosity seen in simpler scenarios becomes manageability as you scale due to
separation of concerns.

public class User
{
   @Id
   @Column( nullable=false, length=15 )
   private String userName;

   @Lob
   @Column( nullable=false )
   private byte [] passwordHash;

   private String email;

   @Column( nullable=false )
   private String firstName;

   @Column( nullable=false )
   private String lastName;

   @Column( nullable=false )
   private Timestamp birthDate;

   @Column( nullable=false )
   private Timestamp memberSince;

   private String penName;

   @Lob
   private byte[] avatar;

   @OneToMany
   Set <Rating> ratings;

   @OneToMany
   Set <MyStuff> myStuff;

   // getters and setters elided
   // setters could verify things like regexes
   // but should leave that to another layer

   @Override
   public String toString()
   {
     return userName;
   }

   @Override
   public boolean equals( Object oth )
   {
     if ( this == oth ) return true;
     if ( ! (oth instanceof User) ) return false;

     final String otherName = ((User) oth).userName;
     return (userName == null? otherName == null
             : userName.equals( otherName ));
   }

   @Override
   public int hashCode()
   {
     return (userName == null? 0 : userName.hashCode());
   }

}

Who was the better writer: Charles Dickens, Ernest Hemingway or Miguel de
Cervantes?

--
Lew