Hibernate2和3中关于sequence的配置区别

hbm映射文件中的配置：

        <id

                name="id"

                column="id"

                type="string"

                length="20"

                unsaved-value="null"

                >

            <generator class="sequence">

                <param name="sequence">t_ptvosp_order_model_seq</param>

            </generator>

        </id>

即id主键为string类型，但使用了sequence来自动生成主键。此时在hibernate2中报错，但hibernate3却没问题，为什么呢？

2中报错net.sf.hibernate.id.IdentifierGenerationException: this id generator generates long, integer, short，源码对比

2:

       public static Serializable get(ResultSet rs, Type type, SessionImplementor session, Object owner) throws SQLException, IdentifierGenerationException {

              Class clazz = type.getReturnedClass();

              if ( clazz==Long.class ) {

                     return new Long( rs.getLong(1) );

              }

              else if ( clazz==Integer.class ) {

                     return new Integer( rs.getInt(1) );

              }

              else if ( clazz==Short.class ) {

                     return new Short( rs.getShort(1) );

              }

              else {

                     throw new IdentifierGenerationException("this id generator generates long, integer, short");

              }

       }

3:

       public static Serializable get(ResultSet rs, Type type) throws SQLException, IdentifierGenerationException {

              Class clazz = type.getReturnedClass();

              if ( clazz == Long.class ) {

                     return new Long( rs.getLong( 1 ) );

              }

              else if ( clazz == Integer.class ) {

                     return new Integer( rs.getInt( 1 ) );

              }

              else if ( clazz == Short.class ) {

                     return new Short( rs.getShort( 1 ) );

              }

              else if ( clazz == String.class ) {

                     return rs.getString( 1 );

              }

              else {

                     throw new IdentifierGenerationException( "this id generator generates long, integer, short or string" );

              }

 

       }

即hibernate2不支持id使用string类型，且还使用sequence的情况。

 

解决：

1)id使用integer之类的数字类型

2)升级为hibernate3