# hodao

**Repository Path**: mirrors_tomitribe/hodao

## Basic Information

- **Project Name**: hodao
- **Description**: ssh connectors
- **Primary Language**: Unknown
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-09-26
- **Last Updated**: 2026-02-15

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

= Hodao
:showtitle:

Helper library for DAOs.  Inspired by the great Hodor himself.  Boilerplate persistence code tends to be like him
-- simple and repetitive.

Hodor hodor hodor persist. Hodor hodor hodor merge.  Hodor hodor hodor delete.  Hodor HODOR!

Hodao takes advantage of Apache TomEE's abstract-bean concept.  The DAO is declared abstract and boilerplate methods
can be simply annotated and handled by the framework.  Unlike purely interface-based approaches, this still allows
you to use plain Java code for persistence logic that falls outside what the framework handles.

The guts of the "framework" are https://github.com/tomitribe/hodao/blob/master/src/main/java/org/tomitribe/hodao/impl/PersistenceHandler.java[less than 500 lines of code].
The rest is pure annotations. *Copy/paste reuse encouraged, forks encouraged, _change it to fit you_!*

Requires Apache TomEE 1.5.x or newer.

== Usage

To use, simply declare your EJB as abstract and implement _java.lang.reflect.InvocationHandler_ as follows.

[source,java]
----
import org.tomitribe.hodao.impl.PersistenceHandler;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;

@Stateless
public abstract class BookCrud implements InvocationHandler {

    @PersistenceContext
    private EntityManager em;

    //...

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        return PersistenceHandler.invoke(this.em, method, args);
    }
}
----

From here you can leverage the following annotations to abstract out common _javax.persistence.EntityManager_ boilerplate.

- org.tomitribe.hodao.Find
- org.tomitribe.hodao.Merge
- org.tomitribe.hodao.Persist
- org.tomitribe.hodao.Remove
- org.tomitribe.hodao.NamedQuery
- org.tomitribe.hodao.QueryString

All of which map to their simple JPA _EntityManager_ equivalent.

=== Simple example

[source,java]
----
import org.tomitribe.hodao.Find;
import org.tomitribe.hodao.MaxResults;
import org.tomitribe.hodao.Merge;
import org.tomitribe.hodao.NamedQuery;
import org.tomitribe.hodao.Offset;
import org.tomitribe.hodao.Optional;
import org.tomitribe.hodao.Persist;
import org.tomitribe.hodao.QueryParam;
import org.tomitribe.hodao.impl.PersistenceHandler;

import javax.ejb.Lock;
import javax.ejb.LockType;
import javax.ejb.Singleton;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.util.List;

@Singleton
@Lock(LockType.READ)
public abstract class BookDao implements InvocationHandler {

    @PersistenceContext
    private EntityManager em;

    @Persist
    public abstract Book create(final Book book);

    @Merge
    public abstract Book update(final Book book);

    @Find
    public abstract Book find(Long id);

    @NamedQuery(Book.FIND_BY_TITLE)
    @Optional
    public abstract List<Book> findBooksByTitle(@QueryParam("title") final String title);

    @NamedQuery(Book.FIND_ALL)
    @Optional
    public abstract List<Book> findAll(@Offset final Integer offset, @MaxResults final Integer max);

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        return PersistenceHandler.invoke(this.em, method, args);
    }
}
----

=== @Persist for _EntityManager.persist_

Valid examples of _@Persist_ include:

[source,java]
----
    @Persist
    public abstract Book create(final Book book);

    @Persist
    public abstract void anotherAwesomeMovie(final Movie movie);
----


=== @Merge for _EntityManager.merge_

Valid examples of _@Merge_ include:

[source,java]
----
    @Merge
    public abstract Book update(final Book book);

    @Merge
    public abstract Color update(final Color color);
----

=== @Find for _EntityManager.find_

Valid examples of _@Find_ include:

[source,java]
----
    @Find
    public abstract Book find(final Long bookId);

    @Find
    public abstract Author whoIsThis(final long authorId);

    @Find
    public abstract Cover giveMe(final int coverId);

    @Find
    public abstract Color lookFor(final ColorID customPrimaryKey);
----

=== @Remove for _EntityManager.remove_

Valid examples of _@Remove_ include:

[source,java]
----
    @Remove
    public abstract void delete(final Book book);

    @Remove
    public abstract void rottenTomatoes(final Movie movie);
----