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This article mainly introduces "hibernate metadata how to use XDoclet tags". In daily operation, I believe that many people have doubts about how hibernate metadata uses XDoclet tags. The editor consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful for you to answer the doubts about how hibernate metadata uses XDoclet tags. Next, please follow the editor to study!

1.Hibernate metadata is marked with XDoclet

Many Hibernate users prefer to use XDoclet@hibernate.tags to embed mapping information directly into the source code. We will not cover this method in this document because, strictly speaking, it is part of XDoclet. However, we include the following example of a Cat class that uses XDoclet mapping.

Package eg; import java.util.Set; import java.util.Date; / * * @ hibernate.class * table= "CATS" * / public class Cat {private Long id; / / identifier private Date birthdate; private Cat mother; private Set kittens private Color color; private char sex; private float weight / * * @ hibernate.id * generator-class= "native" * column= "CAT_ID" * / public Long getId () {return id;} private void setId (Long id) {this.id=id } / * * @ hibernate.many-to-one * column= "PARENT_ID" * / public Cat getMother () {return mother;} void setMother (Cat mother) {this.mother = mother } / * * @ hibernate.property * column= "BIRTH_DATE" * / public Date getBirthdate () {return birthdate;} void setBirthdate (Date date) {birthdate = date;} / * @ hibernate.property * column= "WEIGHT" * / public float getWeight () {return weight } void setWeight (float weight) {this.weight = weight;} / * * @ hibernate.property * column= "COLOR" * not-null= "true" * / public Color getColor () {return color;} void setColor (Color color) {this.color = color } / * * @ hibernate.set * inverse= "true" * order-by= "BIRTH_DATE" * @ hibernate.collection-key * column= "PARENT_ID" * @ hibernate.collection-one-to-many * / public Set getKittens () {return kittens;} void setKittens (Set kittens) {this.kittens = kittens } / / addKitten not needed by Hibernate public void addKitten (Cat kitten) {kittens.add (kitten);} / * * @ hibernate.property * column= "SEX" * not-null= "true" * update= "false" * / public char getSex () {return sex } void setSex (char sex) {this.sex=sex;}}

See the Hibernate website for more examples of Xdoclet and Hibernate

2. Hibernate metadata using JDK 5.0Annotation (Annotation)

JDK 5.0introduces XDoclet-style annotations at the language level and is type-safe and checked at compile time. This mechanism is more powerful than XDoclet annotations and has better tools and IDE support. For example, IntelliJ IDEA supports auto-completion and syntax highlighting of JDK 5.0annotations. The new revision of the EJB specification (JSR-220) uses the annotations of JDK 5.0 as the primary metadata (metadata) mechanism for entity beans.

Hibernate 3 implements the EntityManager of JSR-220 (the persistence API) and supports the definition of mapping metadata through Hibernate Annotations packages. This package is downloaded as a separate section and supports metadata for EJB3 (JSR-220) and Hibernate3.

This is an example of a POJO class annotated as EJB entity bean

@ Entity (access = AccessType.FIELD) public class Customer implements Serializable {@ Id; Long id; String firstName; String lastName; Date birthday; @ Transient Integer age; @ Embedded private Address homeAddress; @ OneToMany (cascade=CascadeType.ALL) @ JoinColumn (name= "CUSTOMER_ID") Set orders / / Getter/setter and business methods} at this point, the study on "how hibernate metadata uses XDoclet tags" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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