tutorial.po

hibernate-distribution-3.3.1.GA-dist.zip源码

"}]]>"

#: index.docbook:419
msgid ""
"What does <literal>sessionFactory.getCurrentSession()</literal> do? First, "
"you can call it as many times and anywhere you like, once you get hold of "
"your <literal>SessionFactory</literal> (easy thanks to "
"<literal>HibernateUtil</literal>). The <literal>getCurrentSession()</"
"literal> method always returns the \"current\" unit of work. Remember that "
"we switched the configuration option for this mechanism to \"thread\" in "
"<literal>hibernate.cfg.xml</literal>? Hence, the current unit of work is "
"bound to the current Java thread that executes our application. However, "
"this is not the full picture, you also have to consider scope, when a unit "
"of work begins and when it ends."
msgstr ""
"Leemos algunos argumentos de la l&#x00ed;nea de comandos, y si el primer "
"argumento es \"store\", creamos y almacenamos un nuevo Event:"

#: index.docbook:430
msgid ""
"A <literal>Session</literal> begins when it is first needed, when the first "
"call to <literal>getCurrentSession()</literal> is made. It is then bound by "
"Hibernate to the current thread. When the transaction ends, either through "
"commit or rollback, Hibernate automatically unbinds the <literal>Session</"
"literal> from the thread and closes it for you. If you call "
"<literal>getCurrentSession()</literal> again, you get a new "
"<literal>Session</literal> and can start a new unit of work. This "
"<emphasis>thread-bound</emphasis> programming model is the most popular way "
"of using Hibernate, as it allows flexible layering of your code (transaction "
"demarcation code can be separated from data access code, we'll do this later "
"in this tutorial)."
msgstr ""
"<![CDATA[private void createAndStoreEvent(String title, Date theDate) {\n"
"    Session session = HibernateUtil.currentSession();\n"
"    Transaction tx = session.beginTransaction();\n"
"\n"
"    Event theEvent = new Event();\n"
"    theEvent.setTitle(title);\n"
"    theEvent.setDate(theDate);\n"
"\n"
"    session.save(theEvent);\n"
"\n"
"    tx.commit();\n"
"    HibernateUtil.closeSession();\n"
"}]]>"

#: index.docbook:441
msgid ""
"Related to the unit of work scope, should the Hibernate <literal>Session</"
"literal> be used to execute one or several database operations? The above "
"example uses one <literal>Session</literal> for one operation. This is pure "
"coincidence, the example is just not complex enough to show any other "
"approach. The scope of a Hibernate <literal>Session</literal> is flexible "
"but you should never design your application to use a new Hibernate "
"<literal>Session</literal> for <emphasis>every</emphasis> database "
"operation. So even if you see it a few more times in the following (very "
"trivial) examples, consider <emphasis>session-per-operation</emphasis> an "
"anti-pattern. A real (web) application is shown later in this tutorial."
msgstr ""
"Creamos un nuevo objeto <literal>Event</literal>, y se lo damos a Hibernate. "
"Hibernate cuida ahora del SQL y ejecuta <literal>INSERT</literal>s en la "
"base de datos. Echemos una mirada al c&#x00f3;digo de manejo de "
"<literal>Session</literal> y <literal>Transaction</literal> antes de "
"ejecutar esto."

#: index.docbook:452
msgid ""
"Have a look at <xref linkend=\"transactions\"/> for more information about "
"transaction handling and demarcation. We also skipped any error handling and "
"rollback in the previous example."
msgstr ""
"Una <literal>Session</literal> es una sola unidad de trabajo. Podr&#x00ed;a "
"sorprenderte que tengamos una API adicional, <literal>Transaction</literal>. "
"Esto implica que una unidad de trabajo puede ser \"m&#x00e1;s larga\" que "
"una sola transacci&#x00f3;n de base de datos; imagina una unidad de trabajo "
"que se abarca varios ciclos petici&#x00f3;n/respuesta HTTP (por ejemplo, un "
"di&#x00e1;logo asistente) en una aplicaci&#x00f3;n web. Separar las "
"transacciones de base de datos de \"las unidades de trabajo de la "
"aplicaci&#x00f3;n desde el punto de vista del usuario\" es uno de los "
"conceptos b&#x00e1;sicos de dise&#x00f1;o de Hibernate. Llamamos una unidad "
"de trabajo larga <emphasis>Transacci&#x00f3;n de Aplicaci&#x00f3;n</"
"emphasis>, usualmente encapsulando varias transacciones de base de datos "
"m&#x00e1;s cortas. Por ahora mantendremos las cosas simples y asumiremos una "
"granularidad uno-a-uno entre una <literal>Session</literal> y una "
"<literal>Transaction</literal>."

#: index.docbook:458
msgid ""
"To run this first routine we have to add a callable target to the Ant build "
"file:"
msgstr ""
"¿Qu&#x00e9; es lo que hacen <literal>Transaction.begin()</literal> y "
"<literal>commit()</literal>? ¿D&#x00f3;nde est&#x00e1; el rollback en caso "
"que algo vaya mal? La API de <literal>Transaction</literal> de Hibernate es "
"opcional realmente, pero la usamos por conveniencia y portabilidad. Si "
"manejases la transacci&#x00f3;n de base de datos por ti mismo (por ejemplo, "
"llamando a <literal>session.connection.commit()</literal>), ligar&#x00ed;as "
"el c&#x00f3;digo a un entorno de despliegue particular, en este JDBC directo "
"no manejado. Estableciendo la f&#x00e1;brica de <literal>Transaction</"
"literal> en tu configuraci&#x00f3;n de Hibernate puedes desplegar tu capa de "
"persistencia en cualquier sitio. Echa una mirada al <xref linkend="
"\"transactions\"/> para m&#x00e1;s informaci&#x00f3;n sobre manejo y "
"demarcaci&#x00f3;n de transacciones. Hemos saltado tambi&#x00e9;n cualquier "
"manejo de excepciones y rollback en este ejemplo."

#: index.docbook:462
msgid ""
"<![CDATA[<target name=\"run\" depends=\"compile\">\n"
"    <java fork=\"true\" classname=\"events.EventManager\" classpathref="
"\"libraries\">\n"
"        <classpath path=\"${targetdir}\"/>\n"
"        <arg value=\"${action}\"/>\n"
"    </java>\n"
"</target>]]>"
msgstr ""
"Para ejecutar la primera rutina tenemos que agregar un objetivo llamable al "
"fichero de construcci&#x00f3;n de Ant:"

#: index.docbook:464
msgid ""
"The value of the <literal>action</literal> argument is set on the command "
"line when calling the target:"
msgstr ""
"<![CDATA[<target name=\"run\" depends=\"compile\">\n"
"    <java fork=\"true\" classname=\"EventManager\" classpathref=\"libraries"
"\">\n"
"        <classpath path=\"${targetdir}\"/>\n"
"        <arg value=\"${action}\"/>\n"
"    </java>\n"
"</target>]]>"

#: index.docbook:469
msgid "<![CDATA[C:\\hibernateTutorial\\>ant run -Daction=store]]>"
msgstr ""
"El valor del argumento <literal>action</literal> es establecido por l&#x00ed;"
"nea de comandos al llamar al objetivo:"

#: index.docbook:471
msgid ""
"You should see, after compilation, Hibernate starting up and, depending on "
"your configuration, lots of log output. At the end you will find the "
"following line:"
msgstr "<![CDATA[C:\\hibernateTutorial\\>ant run -Daction=store]]>"

#: index.docbook:476
msgid ""
"<![CDATA[[java] Hibernate: insert into EVENTS (EVENT_DATE, title, EVENT_ID) "
"values (?, ?, ?)]]>"
msgstr ""
"Debes ver, despu&#x00e9;s de la compilaci&#x00f3;n, a Hibernate arrancando "
"y, dependiendo de tu configuraci&#x00f3;n mucha salida de registro (log). Al "
"final encontrar&#x00e1;s la siguiente l&#x00ed;nea:"

#: index.docbook:478
msgid ""
"This is the <literal>INSERT</literal> executed by Hibernate, the question "
"marks represent JDBC bind parameters. To see the values bound as arguments, "
"or to reduce the verbosity of the log, check your <literal>log4j.properties</"
"literal>."
msgstr ""
"<![CDATA[[java] Hibernate: insert into EVENTS (EVENT_DATE, title, EVENT_ID) "
"values (?, ?, ?)]]>"

#: index.docbook:484
msgid ""
"Now we'd like to list stored events as well, so we add an option to the main "
"method:"
msgstr ""
"Esta es la <literal>INSERT</literal> ejecutada por Hibernate, los signos de "
"preguntas representan par&#x00e1;metros de ligado JDBC. Para ver los valores "
"ligados como argumentos, o para reducir la verborragia del registro, chequea "
"tu <literal>log4j.properties</literal>."

#: index.docbook:488
msgid ""
"<![CDATA[if (args[0].equals(\"store\")) {\n"
"    mgr.createAndStoreEvent(\"My Event\", new Date());\n"
"}\n"
"else if (args[0].equals(\"list\")) {\n"
"    List events = mgr.listEvents();\n"
"    for (int i = 0; i < events.size(); i++) {\n"
"        Event theEvent = (Event) events.get(i);\n"
"        System.out.println(\"Event: \" + theEvent.getTitle() +\n"
"                           \" Time: \" + theEvent.getDate());\n"
"    }\n"
"}]]>"
msgstr ""
"Ahora quisi&#x00e9;ramos listar acontecimientos almacenados tambi&#x00e9;n, "
"as&#x00ed; que agregamos una opci&#x00f3;n al m&#x00e9;todo principal:"

#: index.docbook:490
msgid "We also add a new <literal>listEvents() method</literal>:"
msgstr ""
"<![CDATA[if (args[0].equals(\"store\")) {\n"
"    mgr.createAndStoreEvent(\"My Event\", new Date());\n"
"}\n"
"else if (args[0].equals(\"list\")) {\n"
"    List events = mgr.listEvents();\n"
"    for (int i = 0; i < events.size(); i++) {\n"
"        Event theEvent = (Event) events.get(i);\n"
"        System.out.println(\"Event: \" + theEvent.getTitle() +\n"
"                           \" Time: \" + theEvent.getDate());\n"
"    }\n"
"}]]>"

#: index.docbook:494
msgid ""
"<![CDATA[private List listEvents() {\n"
"\n"
"    Session session = HibernateUtil.getSessionFactory().getCurrentSession"
"();\n"
"\n"
"    session.beginTransaction();\n"
"\n"
"    List result = session.createQuery(\"from Event\").list();\n"
"\n"
"    session.getTransaction().commit();\n"
"\n"
"    return result;\n"
"}]]>"
msgstr ""
"Agregamos tambi&#x00e9;n un nuevo m&#x00e9;todo <literal>listEvents()</"
"literal>:"

#: index.docbook:496
msgid ""
"What we do here is use an HQL (Hibernate Query Language) query to load all "
"existing <literal>Event</literal> objects from the database. Hibernate will "
"generate the appropriate SQL, send it to the database and populate "
"<literal>Event</literal> objects with the data. You can create more complex "
"queries with HQL, of course."
msgstr ""
"<![CDATA[private List listEvents() {\n"
"    Session session = HibernateUtil.currentSession();\n"
"    Transaction tx = session.beginTransaction();\n"
"\n"
"    List result = session.createQuery(\"from Event\").list();\n"
"\n"
"    tx.commit();\n"
"    session.close();\n"
"\n"
"    return result;\n"
"}]]>"

#: index.docbook:503
msgid "Now, to execute and test all of this, follow these steps:"
msgstr ""
"Lo que hacemos aqu&#x00ed; es usar una consulta HQL (Lenguaje de Consulta de "
"Hibernate o Hibernate Query Language) para cargar todos los objetos "
"<literal>Event</literal> existentes de la base de datos. Hibernate "
"generar&#x00e1; el SQL apropiado, lo enviar&#x00e1; a la base de datosy "
"poblar&#x00e1; los objetos <literal>Event</literal> con datos. Puedes, por "
"supuesto, crear consultas m&#x00e1;s complejas con HQL."

#: index.docbook:509
msgid ""
"Run <literal>ant run -Daction=store</literal> to store something into the "
"database and, of course, to generate the database schema before through "
"hbm2ddl."
msgstr "Now, to execute and test all of this, follow these steps:"

#: index.docbook:515
msgid ""
"Now disable hbm2ddl by commenting out the property in your "
"<literal>hibernate.cfg.xml</literal> file. Usually you only leave it turned "
"on in continous unit testing, but another run of hbm2ddl would "
"<emphasis>drop</emphasis> everything you have stored - the <literal>create</"
"literal> configuration setting actually translates into \"drop all tables "
"from the schema, then re-create all tables, when the SessionFactory is build"
"\"."
msgstr ""
"Run <literal>ant run -Daction=store</literal> to store something into the "
"database and, of course, to generate the database schema before through "
"hbm2ddl."

#: index.docbook:525
msgid ""
"If you now call Ant with <literal>-Daction=list</literal>, you should see "
"the events you have stored so far. You can of course also call the "
"<literal>store</literal> action a few times more."
msgstr ""
"Now disable hbm2ddl by commenting out the property in your "
"<literal>hibernate.cfg.xml</literal> file. Usually you only leave it turned "
"on in continous unit testing, but another run of hbm2ddl would "
"<emphasis>drop</emphasis> everything you have stored - the <literal>create</"
"literal> configuration setting actually translates into \"drop all tables "
"from the schema, then re-create all tables, when the SessionFactory is build"
"\"."

#: index.docbook:531
msgid ""
"Note: Most new Hibernate users fail at this point and we see questions about "
"<emphasis>Table not found</emphasis> error messages regularly. However, if "
"you follow the steps outlined above you will not have this problem, as "
"hbm2ddl creates the database schema on the first run, and subsequent "
"application restarts will use this schema. If you change the mapping and/or "
"database schema, you have to re-enable hbm2ddl once again."
msgstr ""
"If you now call Ant with <literal>-Daction=list</literal>, you should see "
"the events you have stored so far. You can of course also call the "
"<literal>store</literal> action a few times more."

#: index.docbook:544
msgid "Part 2 - Mapping associations"
msgstr ""
"Note: Most new Hibernate users fail at this point and we see questions about "
"<emphasis>Table not found</emphasis> error messages regularly. However, if "
"you follow the steps outlined above you will not have this problem, as "
"hbm2ddl creates the database schema on the first run, and subsequent "
"application restarts will use this schema. If you change the mapping and/or "
"database schema, you have to re-enable hbm2ddl once again."

#: index.docbook:546
msgid ""
"We mapped a persistent entity class to a table. Let's build on this and add "
"some class asso