blocks|key|3329743|text|编辑生成的代码文件并不是一个好主意，无论是通过编辑文件本身还是通过子类化。无论您做什么，请确保保持由该工具创建的签名完好无损，以便将来可以理解该文件是自动生成的。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3329744|我建议您研究一下这些工具的命令选项，看看它们是否为您提供了一定的灵活性。一些工具可以生成抽象的类或接口，而不是具体的类。如果无法做到这一点，请创建一个域对象，其中包含自动生成的对象作为成员变量。|3329745|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

It is not a good idea to edit generated code files, either by editing the files them selves or by subclassing. Whatever you do, be sure to leave the signature created by the tool intact, so that it will be possible to understand in the future that the file was auto-generated.

I recommend that you research the command options of the tools to see if they allow you some flexibility. Some tools can generate abstract classes or interfaces instead of concrete classes. If this is not possible, create a domain object that includes the autogenerated object as a member variable.

blocks|key|343713|text|至于Hibernate，你可以调整代码生成中使用的模板文件来改变它们的行为。如果要调整可编辑的HIbernate工具，例如：dao/daohome.ftl|type|unstyled|depth|inlineStyleRanges|offset|length|style|BOLD|entityRanges|data|343714|您甚至可以在编辑.hbm.xml文件时向"toString()“输出中添加字段|343715|...
<property+name="note"+type="string">
++++<meta+attribute="use-in-tostring">true</meta>
++++<column+name="note"+/>
</property>
...|code-block|syntax|javascript|343716|对于日志和验证，您都可以考虑使用AOP+with+AspectJ+(我不建议修改生成的代码，因为您可能希望从头开始多次构建)。|343717|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/AspectJ^0|1Q|F|0|8|8|0|0|G|G|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Z|8|@$9|10|A|11|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|12|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|13|8|@]|D|@$9|14|A|15|1|16]]|E|$]]|$1|O|3|-4|5|6|7|17|8|@]|D|@]|E|$]]]|P|$Q|$5|R|S|T|E|$U|V]]]]

As for Hibernate you may tweak the template files used in code generation to change their behaviour. If you want to tweak the HIbernate Tools you can edit, for example: dao/daohome.ftl 

You may even add fields to the "toString()" output editing the .hbm.xml files

<pre><code>...
&lt;property name="note" type="string"&gt;
 &lt;meta attribute="use-in-tostring"&gt;true&lt;/meta&gt;
 &lt;column name="note" /&gt;
&lt;/property&gt;
...
</code></pre>

Both for logging and validation you may consider using <a href="http://en.wikipedia.org/wiki/AspectJ" rel="nofollow noreferrer">AOP with AspectJ</a> (I don't recommend messing with the generated code, since you might want to build that from scratch many times over).

blocks|key|3117201|text|首先，我要重申，修改生成的代码有许多与之相关的问题，在可能的情况下，应该避免这种情况。也就是说，有时在重新生成代码时，避免或付出更多努力是不切实际的，而不是仅仅处理更改。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3117202|遗憾的是，java不支持c#所具有的分部类的概念。这些都是为了解决这类问题。|3117203|您应该查看您的代码生成工具是否支持某种形式的有意义的注释，这些注释可以分隔您自己在类中添加的区域(如果您正在修改代码，而不是添加到代码中，这是不太可能的，也不会有任何帮助)|3117204|如果您真的希望这样做，最好的选择是最初生成文件，但立即将它们签入版本控制存储库。然后进行更改，将其签入。|3117205|下次您重新运行这些工具并让它们覆盖现有文件时，您可以与受源代码控制的文件进行比较，并将更改合并回来(大多数微不足道的更改，如添加新的列/表，都将是微不足道的。|3117206|如果代码生成器突然生成完全不同的代码(比如一个新版本)，这将不会对您有多大帮助，但在这种情况下，您添加的任何代码，而不是简单的附加便利方法(依赖于已经公开的数据/方法)，无论它如何混合到类中，都会出现问题。然而，版本控制系统仍然有帮助，因为它还记录了原始的更改，因此您可以看到之前添加的内容，以及您需要在新样式中重新创建的内容。|3117207|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|P|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|Q|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|R|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|S|8|@]|9|@]|A|$]]|$1|L|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|M|$]]

First I would reiterate that modification of generated code has many problems associated with it and that, where possible it should be avoided. That said sometimes this is impractical to avoid or more effort than just dealing with the changes when the code is regenerated.

Sadly java doesn't support the concept of partial classes that c# has. These are precisely to solve this sort of problem.

You should see if your code generation tools support some form of meaningful comments which delimit regions added by yourself in the class (this is unlikely and won't help if you are modifying the code rather than adding to it)

You best option if you really wish to do this is to generate the files initially but check them into a version control repository immediately.
Then make your changes, check that in.

Next time you rerun the tools and let them overwrite the existing files you can diff against your source controlled ones and merge the changes back in (most trivial changes like addition of new columns/tables will be little effort.

This will not help you as much if the code generator suddenly generates radically different code (say a new version) but in those cases any code you added which wasn't simply additional convenience methods relying on data/methods already exposed publicly) will have problems no matter how it is mixed into the class. The version control system does still help however since it also records the original changes so you can see what you had added previously and what, one would assume, you need to recreate in the new style.

blocks|key|344654|text|对于JAXB，请参阅Adding+Behaviours。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|344655|基本上，将JAXB配置为返回通常期望的对象的自定义实例。在下面的示例中，您将创建一个新对象PersonEx，它扩展了JAXB对象Person。这种机制可以很好地工作，因为您是从生成的类派生的，并且根本不会更改JAXB类或模式。|344656|package+org.acme.foo.impl;

class+PersonEx+extends+Person+{
++@Override
++public+void+setName(String+name)+{
++++if(name.length()<3)+throw+new+IllegalArgumentException();
++++super.setName(name);
++}
}

@XmlRegistry
class+ObjectFactoryEx+extends+ObjectFactory+{
++@Override
++Person+createPerson()+{
++++return+new+PersonEx();
++}
}|code-block|syntax|javascript|344657|请注意，@Override指令在JAXB对象发生更改的情况下非常重要-它将防止您的定制成为孤立的。|344658|entityMap|0|LINK|mutability|MUTABLE|url|https://jaxb.java.net/guide/Adding_behaviors.html^0|A|H|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@$A|V|B|W|1|X]]|C|$]]|$1|D|3|E|5|6|7|Y|8|@]|9|@]|C|$]]|$1|F|3|G|5|H|7|Z|8|@]|9|@]|C|$I|J]]|$1|K|3|L|5|6|7|10|8|@]|9|@]|C|$]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|C|$]]]|N|$O|$5|P|Q|R|C|$S|T]]]]

For JAXB, see <a href="https://jaxb.java.net/guide/Adding_behaviors.html" rel="noreferrer">Adding Behaviours</a>.

Basically, you configure JAXB to return a custom instance of the object you'd normally expect. In the below example you create a new object PersonEx which extends the JAXB object Person. This mechanism works well in that you're deriving from the generated classes, and not altering the JAXB classes or schemas at all.

<pre><code>package org.acme.foo.impl;

class PersonEx extends Person {
 @Override
 public void setName(String name) {
 if(name.length()&lt;3) throw new IllegalArgumentException();
 super.setName(name);
 }
}

@XmlRegistry
class ObjectFactoryEx extends ObjectFactory {
 @Override
 Person createPerson() {
 return new PersonEx();
 }
}
</code></pre>

Note that the @Override directive is important in case your JAXB object changes - it will prevent your customisation becoming orphaned.

blocks|key|3117250|text|AOP的引用很好。我将添加Spring，它内置了非常好的AOP特性。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3117251|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

The AOP citation is a good one. I'll add Spring, which has very nice AOP features built in.

blocks|key|3117258|text|我使用Hibernate的方法是生成基类，然后扩展基类。我将我的所有业务逻辑(如果有)添加到这些子类中。我还经常更改Hibernate使用的FreeMarker模板，以进一步定制生成的类。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3117259|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

The way I have used Hibernate is to generate base classes that I then extend. I add all my business logic (if any) to these subclasses. I quite often also end up changing the FreeMarker templates used by Hibernate to further customize the generated classes.

blocks|key|343787|text|看一看|type|unstyled|depth|inlineStyleRanges|entityRanges|data|343788|http://code.google.com/p/jaxb-method-inserter/|offset|length|343789|这是我为JAXB写的一个小插件，使用起来非常简单。希望它能帮上忙|343790|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|1A|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@$D|Q|E|R|1|S]]|A|$]]|$1|F|3|G|5|6|7|T|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|U|8|@]|9|@]|A|$]]]|I|$J|$5|K|L|M|A|$N|C]]]]

Have a look at 

<a href="http://code.google.com/p/jaxb-method-inserter/" rel="nofollow">http://code.google.com/p/jaxb-method-inserter/</a>

Its a small plugin for JAXB I wrote, Its quite simple to uses. Hope it help

With generated Java source code, like

<ul>
<li>code generated with Hibernate tools</li>
<li>code generated with JAXB schema binding (xjc)</li>
<li>code generated with WDSL2Java (cxf)</li>
</ul>

all generated classes are "value object" types, without business logic. And if I add methods to the generated source code, I will loose these methods if I repeat the source code generation.

Do these Java code generation tools offer ways to "extend" the generated code?

For example, 

<ul>
<li>to override the ToString method (for logging)</li>
<li>to implement the visitor pattern (for data analysis / validation)</li>
</ul>

How can I extend Java code generated by JAXB, CXF or Hibernate tools?

使用生成的Java源代码，例如使用Hibernate工具生成的代码使用JAXB架构绑定(Xjc)生成的代码使用WDSL2Java (cxf)生成的代码所有生成的类都是“值对象”类型，没有业务逻辑。如果我将方法添加到生成的源代码中，如果我重复源代码生成，我将丢失这些方法。这些Java代码生成工具是否提供了“扩展”生成的代...

问如何扩展JAXB、CXF或Hibernate工具生成的Java代码？
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