persistent_classes.po

hibernate 开源框架的代码 jar包希望大家能喜欢

msgid ""
msgstr ""
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"POT-Creation-Date: 2007-10-25 01:01+0000\n"
"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
"Language-Team: LANGUAGE <[e-mail]>\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"

#. Tag: title
#: persistent_classes.xml:5
#, no-c-format
msgid "Persistent Classes"
msgstr "持久化类(Persistent Classes)"

#. Tag: para
#: persistent_classes.xml:7
#, no-c-format
msgid ""
"Persistent classes are classes in an application that implement the entities "
"of the business problem (e.g. Customer and Order in an E-commerce "
"application). Not all instances of a persistent class are considered to be "
"in the persistent state - an instance may instead be transient or detached."
msgstr ""
"在应用程序中，用来实现业务问题实体的（如，在电子商务应用程序中的Customer和"
"Order） 类就是持久化类。不能认为所有的持久化类的实例都是持久的状态——一个实例"
"的状态也可能 是瞬时的或脱管的。"

#. Tag: para
#: persistent_classes.xml:14
#, no-c-format
msgid ""
"Hibernate works best if these classes follow some simple rules, also known "
"as the Plain Old Java Object (POJO) programming model. However, none of "
"these rules are hard requirements. Indeed, Hibernate3 assumes very little "
"about the nature of your persistent objects. You may express a domain model "
"in other ways: using trees of <literal>Map</literal> instances, for example."
msgstr ""
"如果这些持久化类遵循一些简单的规则，Hibernate能够工作得更好，这些规则也被称"
"作 简单传统Java对象(POJO:Plain Old Java Object)编程模型。但是这些规则并不是必"
"需的。 实际上，Hibernate3对于你的持久化类几乎不做任何设想。你可以用其他的方法"
"来表达领域模型： 比如，使用<literal>Map</literal>实例的树型结构。"

#. Tag: title
#: persistent_classes.xml:23
#, no-c-format
msgid "A simple POJO example"
msgstr "一个简单的POJO例子"

#. Tag: para
#: persistent_classes.xml:25
#, no-c-format
msgid "Most Java applications require a persistent class representing felines."
msgstr "大多数Java程序需要用一个持久化类来表示猫科动物。"

#. Tag: programlisting
#: persistent_classes.xml:29
#, no-c-format
msgid ""
"<![CDATA[package eg;\n"
"import java.util.Set;\n"
"import java.util.Date;\n"
"\n"
"public class Cat {\n"
"    private Long id; // identifier\n"
"\n"
"    private Date birthdate;\n"
"    private Color color;\n"
"    private char sex;\n"
"    private float weight;\n"
"    private int litterId;\n"
"\n"
"    private Cat mother;\n"
"    private Set kittens = new HashSet();\n"
"\n"
"    private void setId(Long id) {\n"
"        this.id=id;\n"
"    }\n"
"    public Long getId() {\n"
"        return id;\n"
"    }\n"
"\n"
"    void setBirthdate(Date date) {\n"
"        birthdate = date;\n"
"    }\n"
"    public Date getBirthdate() {\n"
"        return birthdate;\n"
"    }\n"
"\n"
"    void setWeight(float weight) {\n"
"        this.weight = weight;\n"
"    }\n"
"    public float getWeight() {\n"
"        return weight;\n"
"    }\n"
"\n"
"    public Color getColor() {\n"
"        return color;\n"
"    }\n"
"    void setColor(Color color) {\n"
"        this.color = color;\n"
"    }\n"
"\n"
"    void setSex(char sex) {\n"
"        this.sex=sex;\n"
"    }\n"
"    public char getSex() {\n"
"        return sex;\n"
"    }\n"
"\n"
"    void setLitterId(int id) {\n"
"        this.litterId = id;\n"
"    }\n"
"    public int getLitterId() {\n"
"        return litterId;\n"
"    }\n"
"\n"
"    void setMother(Cat mother) {\n"
"        this.mother = mother;\n"
"    }\n"
"    public Cat getMother() {\n"
"        return mother;\n"
"    }\n"
"    void setKittens(Set kittens) {\n"
"        this.kittens = kittens;\n"
"    }\n"
"    public Set getKittens() {\n"
"        return kittens;\n"
"    }\n"
"    \n"
"    // addKitten not needed by Hibernate\n"
"    public void addKitten(Cat kitten) {\n"
"            kitten.setMother(this);\n"
"        kitten.setLitterId( kittens.size() ); \n"
"        kittens.add(kitten);\n"
"    }\n"
"}]]>"
msgstr ""

#. Tag: para
#: persistent_classes.xml:31
#, no-c-format
msgid "There are four main rules to follow here:"
msgstr "这里要遵循四条主要的规则："

#. Tag: title
#: persistent_classes.xml:37
#, no-c-format
msgid "Implement a no-argument constructor"
msgstr "实现一个默认的（即无参数的）构造方法（constructor）"

#. Tag: para
#: persistent_classes.xml:39
#, no-c-format
msgid ""
"<literal>Cat</literal> has a no-argument constructor. All persistent classes "
"must have a default constructor (which may be non-public) so that Hibernate "
"can instantiate them using <literal>Constructor.newInstance()</literal>. We "
"strongly recommend having a default constructor with at least "
"<emphasis>package</emphasis> visibility for runtime proxy generation in "
"Hibernate."
msgstr ""
"<literal>Cat</literal>有一个无参数的构造方法。所有的持久化类都必须有一个 默认"
"的构造方法（可以不是public的），这样的话Hibernate就可以使用 "
"<literal>Constructor.newInstance()</literal>来实例化它们。 我们强烈建议，在"
"Hibernate中，为了运行期代理的生成，构造方法至少是 <emphasis>包(package)</"
"emphasis>内可见的。"

#. Tag: title
#: persistent_classes.xml:49
#, no-c-format
msgid "Provide an identifier property (optional)"
msgstr "提供一个标识属性（identifier property）（可选）"

#. Tag: para
#: persistent_classes.xml:51
#, no-c-format
msgid ""
"<literal>Cat</literal> has a property called <literal>id</literal>. This "
"property maps to the primary key column of a database table. The property "
"might have been called anything, and its type might have been any primitive "
"type, any primitive \"wrapper\" type, <literal>java.lang.String</literal> or "
"<literal>java.util.Date</literal>. (If your legacy database table has "
"composite keys, you can even use a user-defined class with properties of "
"these types - see the section on composite identifiers later.)"
msgstr ""
"<literal>Cat</literal>有一个属性叫做<literal>id</literal>。这个属性映射数据库"
"表的主 键字段。这个属性可以叫任何名字，其类型可以是任何的原始类型、原始类型的"
"包装类型、 <literal>java.lang.String</literal> 或者是 <literal>java.util."
"Date</literal>。 （如果你的遗留数据库表有联合主键，你甚至可以用一个用户自定义"
"的类，该类拥有这些类型 的属性。参见后面的关于联合标识符的章节。）"

#. Tag: para
#: persistent_classes.xml:60
#, no-c-format
msgid ""
"The identifier property is strictly optional. You can leave them off and let "
"Hibernate keep track of object identifiers internally. We do not recommend "
"this, however."
msgstr ""
"标识符属性是可选的。可以不用管它，让Hibernate内部来追踪对象的识别。 但是我们"
"并不推荐这样做。"

#. Tag: para
#: persistent_classes.xml:65
#, no-c-format
msgid ""
"In fact, some functionality is available only to classes which declare an "
"identifier property:"
msgstr "实际上，一些功能只对那些声明了标识符属性的类起作用："

#. Tag: para
#: persistent_classes.xml:72
#, fuzzy, no-c-format
msgid ""
"Transitive reattachment for detached objects (cascade update or cascade "
"merge) - see"
msgstr ""
"托管对象的传播性再连接（级联更新或级联合并） ——参阅 <xref linkend="
"\"objectstate-transitive\"/>"

#. Tag: literal
#: persistent_classes.xml:79
#, no-c-format
msgid "Session.saveOrUpdate()"
msgstr "Session.saveOrUpdate()"

#. Tag: literal
#: persistent_classes.xml:84
#, no-c-format
msgid "Session.merge()"
msgstr "Session.merge()"

#. Tag: para
#: persistent_classes.xml:89
#, no-c-format
msgid ""
"We recommend you declare consistently-named identifier properties on "
"persistent classes. We further recommend that you use a nullable (ie. non-"
"primitive) type."
msgstr ""
"我们建议你对持久化类声明命名一致的标识属性。我们还建议你使用一 个可以为空（也"
"就是说，不是原始类型）的类型。"

#. Tag: title
#: persistent_classes.xml:96
#, no-c-format
msgid "Prefer non-final classes (optional)"
msgstr "使用非final的类 (可选)"

#. Tag: para
#: persistent_classes.xml:97
#, no-c-format
msgid ""
"A central feature of Hibernate, <emphasis>proxies</emphasis>, depends upon "
"the persistent class being either non-final, or the implementation of an "
"interface that declares all public methods."
msgstr ""
"<emphasis>代理（proxies）</emphasis>是Hibernate的一个重要的功能，它依赖的条件"
"是，持久 化类或者是非final的，或者是实现了一个所有方法都声明为public的接口。"

#. Tag: para
#: persistent_classes.xml:102
#, no-c-format
msgid ""
"You can persist <literal>final</literal> classes that do not implement an "
"interface with Hibernate, but you won't be able to use proxies for lazy "