Dynject and JPA / EJB 3.0 / Hibernate

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By means of a specialized binder, Dynject can extract information from JPA-style annotations. To enable this, it's enough to call once somewhere in your code the following:

Shell.registerBinder(new JPABinder());

The following annotations are interpreted:

A @Column annotation with an attribute of length is translated into a @Length annotation.
A @Column anotation with precision/scale attributes is translated into @MaxDigits and @MaxFractionDigits annotations
A @Column annotation with nullable set to false is translated into a @Required annotation
A @Basic annotation with optional set to false is translated into a @Required annotation
A @OneToOne annotation with the optional attribute set to false is translated into a @Required annotation

Here's a small sample illustrating validation:

@Entity
public class TestJPA {
  private String stringField;
  private double dblField;


  @Column(name="dblField", precision=7, scale=3)
  public double getDblField() {
    return dblField;
  }
  public void setDblField(double dblField) {
    this.dblField = dblField;
  }

  @Column(name="stringField", length=10)
  public String getStringField() {
    return stringField;
  }
  public void setStringField(String stringField) {
   this.stringField = stringField;
  }

  public static void main(String[] args) {

   Shell.registerBinder(new JPABinder());

   TestJPA bean = new TestJPA();
   bean.stringField = "Hello World";
   bean.dblField = 12345678;
   ErrorMap errors = Shell.validate(bean);

   System.out.println(errors);
   // An error is printed for DblField, specifying that a MaxDigits 
   // constraint has failed, and another one is printed for StringField,
   // specifying that a Length constraint has been violated.
  }
}

Of course, you are free to combine JPA and Dynject annotations.