Read javax annotations with custom doclet

I got a bunch of DTO's which are not commented at all. However, there are comments in the SQL-Database. I can get these comments by sending a query and then retrieving the ResultSet.

My task is to create a javadoc-API (as HTML) with the comments from the SQL-Database in order to make the codebase better understandable.

After asking about this task already HERE, I tried to looked into creating my own doclet. I then wrote my own doclet by rewriting the Standard-, Abstract- and HtmlDoclet from Java.Tools. My results are working fine and I can create javadoc html pages WITH the comments from the database.

HOWEVER its a massive hack imho. There are two main tasks that need to be done in order to get the Database comments.

know the table name
know the column name

How it should be done: (which is what I want to ask - How do I implement it like this?)

For 1. : Find the @Table annotation. Read name = "tablename".

For 2. : For each variable:

Is there a @Column annotation ? return "columnName" : return ""

How I do it right now:

For 1. : I read the RootDoc.name() variable and then read the String char by char. Find a capital letter. Insert '_'. And at the end, turn everything .toUpperCase(). So "testFile" turns into "TEST_FILE".

This sometimes does not work. If you read carefully in the example class. Its name is "SaklTAdrkla" but the Databasetable name is SAKL_T_ADRKLAS. Parsing the name from RootDoc.name() would result in "SAKL_T_ADRKLA" which is missing the character 'S' at the end, therefore it wont find the table in the database.

For 2. : I get all Fields from the ClassDoc. I then parse Field.name() the same way I parsed the RootDoc.name() variable.

This wont work for the same reason as 1.; but also because some fieldnames are not the same as their mapped names. In the example Class - field sakgTAklgrpAklAkgid is mapped in the database as AKL_AKGID

I am able to find the Annotation itselfe by calling FieldDoc.annotations(). But thats ONLY the annotation without the String (name = "xyz") which is the most important part for me!

I have found the Jax-Doclet, which can parse the javax annotations. However after downloading the jar-source file and implementing the java files, there are numerous dependency issues which are not resolvable because the referenced classes no longer exist in java 8 tools.jar.

Is there another solution, that is capable of reading the javax annotations?

Can I implement something into my doclet so it can read the javax annotations?

Edit:

I found out you can call .elementValues() on the AnnotationDesc class which I can get from FieldDoc.annotations(). However I always get a com.sun.jdi.ClassNotLoadedException Type has not been loaded occurred while retrieving component type of array. To fix it I manually load the classes AnnotationDesc and AnnotationDesc.ElementValuePair by calling Class.forName(). However now the Array with the elementValuePairs is empty..?

Example class:

    /**
 * The persistent class for the SAKL_T_ADRKLAS database table.
 */
@Entity
@IdClass(SaklTAdrklaPK.class)
@Table(name = "SAKL_T_ADRKLAS")
@NamedQuery(name = "SaklTAdrkla.findAll", query = "SELECT s FROM SaklTAdrkla s")
public class SaklTAdrkla implements Serializable, IModelEntity {
   private static final long serialVersionUID = 1L;

   @Id @Column(name = "AKL_AKLID") private String aklAklid;

   @Id
   // uni-directional many-to-one association to SakgTAklgrp
   @JsonBackReference(value = "sakgTAklgrpAklAkgid") @ManyToOne @JoinColumn(name = "AKL_AKGID") private SakgTAklgrp sakgTAklgrpAklAkgid;

   @Temporal(TemporalType.TIMESTAMP) @Column(name = "AKL_AEND") private Date aklAend;

   @Column(name = "AKL_DEFLT") private BigDecimal aklDeflt;

   @Column(name = "AKL_SPERRE") private BigDecimal aklSperre;

   @Column(name = "AKL_T_BEZ") private String aklTBez;

   @Column(name = "AKL_USRID") private String aklUsrid;

   public SaklTAdrkla() {
   }

Solution

It took me quite a while to figure this out now, but I finnally did.

The Problem was that my doclet could find all the annotations, which it displayed in the console as errors.

error: cannot find symbol @Column(name = "TST_USER") private String tstUser;

What I also found was this message in the lot of errors that got thrown:

error: package javax.persistence does not exist import javax.persistence.*;

So I imported javax.persistance.jar into my project. I also added com.fasterxml.jaxkson.annotations.jar into the project since it would also not work without it.

Surprise Surprise! IT WORKS!

I can get all the annotations and annotation values by using annotation.elementValues(). I no longer get an empty Array nor do I get an ClassNotLoadedException.