OpenJPA one to many

One magazine may have multiple article

Unidirectional sample
Here are the annotations on magazine entity

@OneToMany(targetEntity=Article.class, 
    cascade = { CascadeType.PERSIST, CascadeType.REFRESH }, 
    fetch = FetchType.EAGER)  //mappedBy="magazine",
@ElementJoinColumn(name = "MAGAZINE_ID", referencedColumnName = "ID")
// the name is the column name in the article table
@OrderBy
private Collection
 articles;

In the entity of article, don't have reference to magazine.
@ElementJoinColumn is an extension in openJPA.

Bidirectional sample

Annotations in magazine

@OneToMany(mappedBy="magazine", cascade=CascadeType.PERSIST)
private Collection
 articles;

mappedBy="magazine", the magazine here is the property name in Article class.

Annotations in Article

@ManyToOne(fetch=FetchType.LAZY, cascade=CascadeType.PERSIST)
@Column(name = "MAG_ID")
private Magazine magazine;

When persist magazine with a list of articles, you need set magazine into each article explicitly. It is not needed if it is unidirectional.
Here is the sample code

  Magazine magazine = new Magazine();
  magazine.setCoverArticle(article1);
  magazine.setIsbn("isbn00000000009");
  magazine.setTitle("ELLE");
  magazine.setPrice(25.00);
  
  List
 articles = new ArrayList
();
  article2.setMagazine(magazine);   //1*
  article3.setMagazine(magazine);   //2*
  articles.add(article2);
  articles.add(article3);
  
  magazine.setArticles(articles);

  magazineDao.persistMagazine(magazine);

1* and 2* could also be done in setArticles() of the Magazine entity class.

public void setArticles(Collection
 articles){
    this.articles = articles;
    
    for(Article article : articles){
        article.setMagazine(this);
    }
}