Hibernate3中使用enum(多对多映射)一例

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最新推荐文章于 2025-08-02 15:56:32 发布

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分类专栏： Java相关文章标签： hibernate object string exception query class

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本文介绍如何使用 Hibernate 在 Java 中实现枚举类型的持久化，并通过具体代码示例展示了 TAuthor 和 TBook 实体类的设计，以及 Sex 枚举类型的定义与使用。

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参考资料：http://appfuse.org/display/APF/Java+5+Enums+Persistence+with+Hibernate

如下图所示建立工程：

代码如下：

BaseEntity.java

package com.yycs.entity.pkey; import java.io.Serializable; import javax.persistence.Basic; import javax.persistence.Column; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.MappedSuperclass; @MappedSuperclass public class BaseEntity implements Serializable { private static final long serialVersionUID = 1284847848821435330L; @Id @Basic(optional = false) @Column(name = "id", nullable = false) @GeneratedValue(strategy=GenerationType.AUTO) private Integer id; public void setId(Integer id) { this.id = id; } public Integer getId() { return id; } }

TAuthor.java

package com.yycs.entity; import java.util.Date; import java.util.List; import javax.persistence.Basic; import javax.persistence.CascadeType; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.JoinColumn; import javax.persistence.JoinTable; import javax.persistence.ManyToMany; import javax.persistence.NamedQueries; import javax.persistence.NamedQuery; import javax.persistence.Table; import javax.persistence.Temporal; import javax.persistence.TemporalType; import org.hibernate.annotations.Parameter; import org.hibernate.annotations.Type; import com.yycs.entity.pkey.BaseEntity; import com.yycs.model.Sex; @Entity @Table(name = "t_author") @NamedQueries( { @NamedQuery(name = "TAuthor.findAll", query = "SELECT t FROM TAuthor t"), @NamedQuery(name = "TAuthor.findById", query = "SELECT t FROM TAuthor t WHERE t.id = :id"), @NamedQuery(name = "TAuthor.findByAge", query = "SELECT t FROM TAuthor t WHERE t.age = :age"), @NamedQuery(name = "TAuthor.findByBirthday", query = "SELECT t FROM TAuthor t WHERE t.birthday = :birthday"), @NamedQuery(name = "TAuthor.findByName", query = "SELECT t FROM TAuthor t WHERE t.name = :name"), @NamedQuery(name = "TAuthor.findBySex", query = "SELECT t FROM TAuthor t WHERE t.sex = :sex") }) public class TAuthor extends BaseEntity { private static final long serialVersionUID = -1842330327524099153L; @Basic(optional = false) @Column(name = "age", nullable = false) private int age; @Basic(optional = false) @Column(name = "birthday", nullable = false) @Temporal(TemporalType.DATE) private Date birthday; @Basic(optional = false) @Column(name = "name", nullable = false, length = 10) private String name; @Basic(optional = false) @Column(name = "sex", columnDefinition = "integer", nullable = true) @Type(type = "com.yycs.utils.SexType", parameters = { @Parameter(name = "enumClass", value = "com.yycs.model.Sex"), @Parameter(name = "identifierMethod", value = "toInt"), @Parameter(name = "valueOfMethod", value = "fromInt") }) private Sex sex; @JoinTable( name = "t_author_book", joinColumns = { @JoinColumn(name = "author_id", referencedColumnName = "id") }, inverseJoinColumns = { @JoinColumn(name = "book_id", referencedColumnName = "id") }) @ManyToMany(cascade = { CascadeType.ALL }, fetch = FetchType.LAZY) private List<TBook> books; public TAuthor() { } public TAuthor(int age, Date birthday, String name, Sex sex) { this.age = age; this.birthday = birthday; this.name = name; this.sex = sex; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Sex getSex() { return sex; } public void setSex(Sex sex) { this.sex = sex; } public List<TBook> getBooks() { return books; } public void setBooks(List<TBook> books) { this.books = books; } @Override public int hashCode() { int hash = 0; hash += (getId() != null ? getId().hashCode() : 0); return hash; } @Override public boolean equals(Object object) { if (!(object instanceof TAuthor)) { return false; } TAuthor other = (TAuthor) object; if ((this.getId() == null && other.getId() != null) || (this.getId() != null && !this.getId().equals(other.getId()))) { return false; } return true; } @Override public String toString() { return "javaapplication1.TAuthor[id=" + getId() + "]"; } }

TBook.java

package com.yycs.entity; import java.util.Date; import java.util.List; import javax.persistence.Basic; import javax.persistence.CascadeType; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.FetchType; import javax.persistence.JoinColumn; import javax.persistence.JoinTable; import javax.persistence.ManyToMany; import javax.persistence.NamedQueries; import javax.persistence.NamedQuery; import javax.persistence.Table; import javax.persistence.Temporal; import javax.persistence.TemporalType; import com.yycs.entity.pkey.BaseEntity; @Entity @Table(name = "t_book") @NamedQueries( { @NamedQuery(name = "TBook.findAll", query = "SELECT t FROM TBook t"), @NamedQuery(name = "TBook.findById", query = "SELECT t FROM TBook t WHERE t.id = :id"), @NamedQuery(name = "TBook.findByContent", query = "SELECT t FROM TBook t WHERE t.content = :content"), @NamedQuery(name = "TBook.findByIsbn", query = "SELECT t FROM TBook t WHERE t.isbn = :isbn"), @NamedQuery(name = "TBook.findByName", query = "SELECT t FROM TBook t WHERE t.name = :name"), @NamedQuery(name = "TBook.findByPblDt", query = "SELECT t FROM TBook t WHERE t.pblDt = :pblDt") }) public class TBook extends BaseEntity { private static final long serialVersionUID = 6004885243116096425L; @Basic(optional = false) @Column(name = "content", nullable = false, length = 200) private String content; @Basic(optional = false) @Column(name = "isbn", nullable = false, length = 12) private String isbn; @Basic(optional = false) @Column(name = "name", nullable = false, length = 20) private String name; @Basic(optional = false) @Column(name = "pbl_dt", nullable = false) @Temporal(TemporalType.DATE) private Date pblDt; //@ManyToMany(mappedBy = "books") @JoinTable( name = "t_author_book", joinColumns = { @JoinColumn(name = "book_id", referencedColumnName = "id") }, inverseJoinColumns = { @JoinColumn(name = "author_id", referencedColumnName = "id") }) @ManyToMany(cascade = { CascadeType.ALL }, fetch = FetchType.LAZY) private List<TAuthor> authors; public TBook() { } public TBook(String content, String isbn, String name, Date pblDt) { this.content = content; this.isbn = isbn; this.name = name; this.pblDt = pblDt; } public String getContent() { return content; } public void setContent(String content) { this.content = content; } public String getIsbn() { return isbn; } public void setIsbn(String isbn) { this.isbn = isbn; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Date getPblDt() { return pblDt; } public void setPblDt(Date pblDt) { this.pblDt = pblDt; } public List<TAuthor> getAuthors() { return authors; } public void setAuthors(List<TAuthor> authors) { this.authors = authors; } @Override public int hashCode() { int hash = 0; hash += (getId() != null ? getId().hashCode() : 0); return hash; } @Override public boolean equals(Object object) { if (!(object instanceof TBook)) { return false; } TBook other = (TBook) object; if ((this.getId() == null && other.getId() != null) || (this.getId() != null && !this.getId().equals(other.getId()))) { return false; } return true; } @Override public String toString() { return "javaapplication1.TBook[id=" + getId() + "]"; } }

Sex.java

package com.yycs.model; public enum Sex { MALE(1), FEMALE(2); private int value; Sex(int value) { this.value = value; } public int toInt() { return value; } public static Sex fromInt(int value) throws Exception { switch (value) { case 1: return MALE; case 2: return FEMALE; default: throw new Exception(); } } public String toString() { switch (this) { case MALE: return "Male"; case FEMALE: return "Female"; default: return null; } } }

SexType.java

package com.yycs.utils; import java.io.Serializable; import java.lang.reflect.Method; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.Properties; import org.hibernate.HibernateException; import org.hibernate.type.NullableType; import org.hibernate.type.TypeFactory; import org.hibernate.usertype.ParameterizedType; import org.hibernate.usertype.UserType; public class SexType implements UserType, ParameterizedType { private static final String DEFAULT_IDENTIFIER_METHOD_NAME = "name"; private static final String DEFAULT_VALUE_OF_METHOD_NAME = "valueOf"; private Class<? extends Enum> enumClass; private Class<?> identifierType; private Method identifierMethod; private Method valueOfMethod; private NullableType type; private int[] sqlTypes; public void setParameterValues(Properties parameters) { String enumClassName = parameters.getProperty("enumClass"); try { enumClass = Class.forName(enumClassName).asSubclass(Enum.class); } catch (ClassNotFoundException cfne) { throw new HibernateException("Enum class not found", cfne); } String identifierMethodName = parameters.getProperty("identifierMethod", DEFAULT_IDENTIFIER_METHOD_NAME); try { identifierMethod = enumClass.getMethod(identifierMethodName, new Class[0]); identifierType = identifierMethod.getReturnType(); } catch (Exception e) { throw new HibernateException("Failed to obtain identifier method", e); } type = (NullableType) TypeFactory.basic(identifierType.getName()); if (type == null) throw new HibernateException("Unsupported identifier type " + identifierType.getName()); sqlTypes = new int[] { type.sqlType() }; String valueOfMethodName = parameters.getProperty("valueOfMethod", DEFAULT_VALUE_OF_METHOD_NAME); try { valueOfMethod = enumClass.getMethod(valueOfMethodName, new Class[] { identifierType }); } catch (Exception e) { throw new HibernateException("Failed to obtain valueOf method", e); } } public Class<?> returnedClass() { return enumClass; } public Object nullSafeGet(ResultSet rs, String[] names, Object owner) throws HibernateException, SQLException { Object identifier = type.get(rs, names[0]); if (identifier == null) { return null; } try { return valueOfMethod.invoke(enumClass, new Object[] { identifier }); } catch (Exception e) { throw new HibernateException("Exception while invoking valueOf method '" + valueOfMethod.getName() + "' of enumeration class '" + enumClass + "'", e); } } public void nullSafeSet(PreparedStatement st, Object value, int index) throws HibernateException, SQLException { try { if (value == null) { st.setNull(index, type.sqlType()); } else { Object identifier = identifierMethod.invoke(value, new Object[0]); type.set(st, identifier, index); } } catch (Exception e) { throw new HibernateException("Exception while invoking identifierMethod '" + identifierMethod.getName() + "' of " + "enumeration class '" + enumClass + "'", e); } } public int[] sqlTypes() { return sqlTypes; } public Object assemble(Serializable cached, Object owner) throws HibernateException { return cached; } public Object deepCopy(Object value) throws HibernateException { return value; } public Serializable disassemble(Object value) throws HibernateException { return (Serializable) value; } public boolean equals(Object x, Object y) throws HibernateException { return x == y; } public int hashCode(Object x) throws HibernateException { return x.hashCode(); } public boolean isMutable() { return false; } public Object replace(Object original, Object target, Object owner) throws HibernateException { return original; } }

Test.java

package com.yycs; import java.util.ArrayList; import java.util.Date; import java.util.List; import org.hibernate.Criteria; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.cfg.AnnotationConfiguration; import org.hibernate.cfg.Configuration; import com.yycs.entity.TAuthor; import com.yycs.entity.TBook; import com.yycs.model.Sex; public class Test { public static void main(String[] args) { Configuration config = new AnnotationConfiguration().configure(); SessionFactory sessionFactory = config.buildSessionFactory(); Session session = sessionFactory.openSession(); TBook book = new TBook("Content", "isbn", "name", new Date()); TAuthor author = new TAuthor(29, new Date(), "shenbin", Sex.MALE); List<TBook> books = new ArrayList<TBook>(); books.add(book); author.setBooks(books); // List<TAuthor> authors = new ArrayList<TAuthor>(); // authors.add(author); // book.setAuthors(authors); Transaction tx = session.beginTransaction(); tx.begin(); session.save(author); tx.commit(); session.close(); session = sessionFactory.openSession(); Criteria criteria = session.createCriteria(TBook.class); List<?> _books = criteria.list(); for (int i = 0; i < _books.size(); i++) { TBook _book = (TBook)_books.get(i); System.out.println(_book.getContent()); System.out.println(_book.getAuthors().get(0).getSex()); } session.close(); session = sessionFactory.openSession(); criteria = session.createCriteria(TAuthor.class); List<?> _authors = criteria.list(); for (int i = 0; i < _authors.size(); i++) { TAuthor _author = (TAuthor)_authors.get(i); System.out.println(_author.getSex()); System.out.println(_author.getBooks().get(0).getContent()); } session.close(); } }

ehcache.xml

hibernate.cfg.xml

<?xml version='1.0' encoding='UTF-8'?> <!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd"> <hibernate-configuration> <session-factory> <property name="hibernate.connection.driver_class">org.hsqldb.jdbcDriver</property> <property name="hibernate.connection.url">jdbc:hsqldb:mem:.</property> <property name="hibernate.dialect">org.hibernate.dialect.HSQLDialect</property> <property name="connection.username">sa</property> <property name="connection.password"></property>  <property name="jdbc.fetch_size">50</property> <property name="jdbc.batch_size">30</property> <property name="show_sql">true</property> <property name="use_outer_join">true</property> <property name="transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property> <property name="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider</property> <property name="hibernate.cache.use_query_cache">true</property> <property name="hibernate.hbm2ddl.auto">create-drop</property> <mapping class="com.yycs.entity.TAuthor" /> <mapping class="com.yycs.entity.TBook" /> </session-factory> </hibernate-configuration>

log4j.properties

log4j.rootLogger=warn, stdout log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.Target=System.out log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L - %m%n

自动生成的表结构如下图所示：