{"id":24,"date":"2005-09-06T14:45:31","date_gmt":"2005-09-06T13:45:31","guid":{"rendered":"http:\/\/www.epischel.de\/wordpress\/?p=24"},"modified":"2009-10-21T21:47:59","modified_gmt":"2009-10-21T20:47:59","slug":"%e2%80%9chibernate-a-developers-notebook%e2%80%9d-migrating-to-hibernate-30-chapter-2","status":"publish","type":"post","link":"https:\/\/www.epischel.de\/wordpress\/2005\/09\/%e2%80%9chibernate-a-developers-notebook%e2%80%9d-migrating-to-hibernate-30-chapter-2\/","title":{"rendered":"„Hibernate – A Developers Notebook“ – migrating to Hibernate 3.0, Chapter 2"},"content":{"rendered":"

This is chapter 2 of rewriting the examples of O’Reillys book „Hibernate – A Developers Notebook“ for using Hibernate<\/a> 3.0 instead of Hibernate 2.x . To get the context, read chapter 1<\/a>.<\/p>\n

The goal of chapter 2 is to write a hbm file for a single table, generating the corresponding java file and compile it.<\/p>\n

A main difference when using Hibernate 3.0 is the ant task definition for hbm2java. It now looks like this:<\/p>\n

\n\n\t\t
\n\n\t\t
\n\t\t\t\t\t\t< View plain text<\/span> ><\/a>\n\t\t\t\t\t<\/div>\n\n\t\t
xml<\/div>\n\n\t\t\n\t\t
\n\n\t<\/div>\n\t\n\t
\n\t\t
  1. <taskdef<\/span> name<\/span>="hibernatetool"<\/span><\/span><\/div><\/li>\n
  2.             classname<\/span>="org.hibernate.tool.ant.HibernateToolTask"<\/span><\/span><\/div><\/li>\n
  3.             classpathref<\/span>="project.class.path"<\/span>\/><\/span><\/span><\/div><\/li>\n
  4.  <\/div><\/li>\n
  5.  <\/div><\/li>\n
  6.     <target<\/span> name<\/span>="codegen"<\/span> depends<\/span>="prepare"<\/span><\/span><\/div><\/li>\n
  7.             description<\/span>="Generate Java source from the O\/R mapping files"<\/span>><\/span><\/span><\/div><\/li>\n
  8.         <hibernatetool<\/span> destdir<\/span>="${source.root}"<\/span>><\/span><\/span><\/div><\/li>\n
  9.         <configuration<\/span> propertyFile<\/span>="${source.root}\/hibernate.properties"<\/span>><\/span><\/span><\/div><\/li>\n
  10.           <fileset<\/span> dir<\/span>="${source.root}"<\/span>><\/span><\/span><\/div><\/li>\n
  11.           <\/div><\/li>\n
  12.             <include<\/span> name<\/span>="**\/*.hbm.xml"<\/span>\/><\/span><\/span><\/div><\/li>\n
  13.           <\/fileset><\/span><\/span><\/span><\/div><\/li>\n
  14.         <\/configuration><\/span><\/span><\/span>        <\/div><\/li>\n
  15.         <hbm2java<\/span> \/><\/span><\/span><\/div><\/li>\n
  16.         <\/div><\/li>\n
  17.      <\/hibernatetool><\/span><\/span><\/span><\/div><\/li>\n
  18.      <\/target><\/span><\/span><\/span><\/div><\/li>\n<\/ol>\t<\/div>\n\n<\/div>\n\n

    Also, the package-name of the schemaexport-task has changed:<\/p>\n

    \n\n\t\t
    \n\n\t\t
    \n\t\t\t\t\t\t< View plain text<\/span> ><\/a>\n\t\t\t\t\t<\/div>\n\n\t\t
    xml<\/div>\n\n\t\t\n\t\t
    \n\n\t<\/div>\n\t\n\t
    \n\t\t
    1. <taskdef<\/span> name<\/span>="schemaexport"<\/span><\/span><\/div><\/li>\n
    2.             classname<\/span>="org.hibernate.tool.hbm2ddl.SchemaExportTask"<\/span><\/span><\/div><\/li>\n
    3.             classpathref<\/span>="project.class.path"<\/span>\/><\/span><\/span><\/div><\/li>\n<\/ol>\t<\/div>\n\n<\/div>\n\n

      Another difference is the jdbc-url for HSQLDB 1.8. You have to insert „file“ as in:<\/p>\n

      \r\njdbc:hsqldb:file:${data.dir}\/music\r\n<\/pre>\n
      (in ant task „db“) or<\/p>\n
      \r\njdbc:hsqldb:file:data\/music\r\n<\/pre>\n
      in hibernate.properties<\/p>\n
      I developed offline so I ran into the problem that the XML parser wants to download the mapping-dtd as advertised in the DOCTYPE-section of the hbm.xml file. I stripped off the http:\/\/www.hibernate.org part of the url, downloaded the dtd and placed it in the root-directory.<\/p>\n
      After using Ant 1.6, everything worked fine. (Otherwise I got:<\/p>\n
      \n\n\t\t
      \n\n\t\t
      \n\t\t\t\t\t\t< View plain text<\/span> ><\/a>\n\t\t\t\t\t<\/div>\n\n\t\t
      java<\/div>\n\n\t\t\n\t\t
      \n\n\t<\/div>\n\t\n\t
      \n\t\t
      1. java.lang<\/span>.NoSuchMethodError<\/span>:<\/span> org.apache<\/span>.tools<\/span>.ant<\/span>.Project<\/span>.createClassLoader<\/span><\/div><\/li>\n
      2.   (<\/span>Lorg\/<\/span>apache\/<\/span>tools\/<\/span>ant\/<\/span>types\/<\/span>Path;<\/span>)<\/span>Lorg\/<\/span>apache\/<\/span>tools\/<\/span>ant\/<\/span>AntClassLoader;<\/span><\/div><\/li>\n
      3.         at org.hibernate<\/span>.tool<\/span>.ant<\/span>.HibernateToolTask<\/span>.execute<\/span>(<\/span>HibernateToolTask.java<\/span>:<\/span>113<\/span>)<\/span><\/div><\/li>\n
      4. )<\/span>...<\/div><\/li>\n<\/ol>\t<\/div>\n\n<\/div>\n\n
        The generated code reveals some differences:<\/p>\n
          \n
        • The type of the volume attribute is java.lang.Short, not short „as advertised“. This is because of the xml-attribute „not-null“ set to null. However if you ommit this xml-attribute, java.lang.Short is used again.\n<\/li>\n
        • There is no all-attributes-as-parameters-constructor.<\/li>\n
        • \nThere is no equals and no hash-code implementation.<\/li>\n<\/ul>\n
          I have not yet any idea about why’s that. Comments are welcome. Point 2 + 3 might be because different code templates.<\/p>\n
          <\/div>","protected":false},"excerpt":{"rendered":"
          This is chapter 2 of rewriting the examples of O’Reillys book „Hibernate – A Developers Notebook“ for using Hibernate 3.0 instead of Hibernate 2.x . To get the context, read chapter 1. The goal of chapter 2 is to write a hbm file for a single table, generating the corresponding java file and compile it.…<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"mf2_syndication":[],"webmentions_disabled_pings":false,"webmentions_disabled":false,"footnotes":""},"categories":[3],"tags":[23,24,120],"series":[],"class_list":["post-24","post","type-post","status-publish","format-standard","hentry","category-java","tag-bucher","tag-hibernate","tag-java","kind-"],"kind":false,"_links":{"self":[{"href":"https:\/\/www.epischel.de\/wordpress\/wp-json\/wp\/v2\/posts\/24","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.epischel.de\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.epischel.de\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.epischel.de\/wordpress\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.epischel.de\/wordpress\/wp-json\/wp\/v2\/comments?post=24"}],"version-history":[{"count":2,"href":"https:\/\/www.epischel.de\/wordpress\/wp-json\/wp\/v2\/posts\/24\/revisions"}],"predecessor-version":[{"id":173,"href":"https:\/\/www.epischel.de\/wordpress\/wp-json\/wp\/v2\/posts\/24\/revisions\/173"}],"wp:attachment":[{"href":"https:\/\/www.epischel.de\/wordpress\/wp-json\/wp\/v2\/media?parent=24"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.epischel.de\/wordpress\/wp-json\/wp\/v2\/categories?post=24"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.epischel.de\/wordpress\/wp-json\/wp\/v2\/tags?post=24"},{"taxonomy":"series","embeddable":true,"href":"https:\/\/www.epischel.de\/wordpress\/wp-json\/wp\/v2\/series?post=24"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}