org.dozer浅析

class="baidu_pl">

class="article_content clearfix">

class="htmledit_views">

本文出自:http://blog.csdn.net/hongchangfirst

dozer是一种JavaBean的映射工具，类似于apache的BeanUtils。但是dozer更强大，它可以灵活的处理复杂类型之间的映射。不但可以进行简单的属性映射、复杂的类型映射、双向映射、递归映射等，并且可以通过XML配置文件进行灵活的配置。

大体来说它可以把一个对象转化为另一个对象，这两个对象之间会有一定的映射规则。

如你有两个类，

class ForeignName

{

private String firstName;

private String lastName;

}

class ChineseName

{

private String firstName;

private String lastName;

}

比如一个中文名字“Hongchang Zhang”,在ForeignName中

firstName="Hongchang";

lastName="Zhang";

但在中国我们的firstName应该是姓，也就是说firstName="Zhang",我们可以采用dozer的map规则进行映射，把ForeignName中的firstName映射为ChineseName的lastName。下述为nameMapper.xml

<?xml version="1.0" class="tags" href="/tags/ENCODING.html" title=encoding>encoding="UTF-8"?>
<mappings xmlns="http://dozer.sourceforge.net"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://dozer.sourceforge.net
http://dozer.sourceforge.net/schema/beanmapping.xsd">

<mapping>
<class-a>ForeignName</class-a>
<class-b>ChineseName</class-b>
<field>
<a>firstName</a>
<b>lastName</b>
</field>
<field>
<a>lastName</a>
<b>firstName</b>
</field>
</mapping>
</mappings>

上边的映射很容易看明白，接下来我们看看具体怎么映射：

ForeignName hc_z = new ForeignName();
hc_z.firstName="Hongchang";

hc_z.lastName="Zhang";

DozerBeanMapper mapper = new DozerBeanMapper();
List<String> mappers = new ArrayList<String>();
mappers.add("nameMapper.xml");
mapper.setMappingFiles(mappers);
ChineseName z_hc = new ChineseName();
mapper.map(hc_z, z_hc);
System.out.println(z_hc.firstName+ " " + z_hc.lastName);

可以看到，很自然的我们得到了"Zhang Hongchang"，当然我们要包含以下包：

class="tags" href="/tags/IMPORT.html" title=import>import java.util.ArrayList;
class="tags" href="/tags/IMPORT.html" title=import>import java.util.List;

class="tags" href="/tags/IMPORT.html" title=import>import org.apache.commons.logging.Log;
class="tags" href="/tags/IMPORT.html" title=import>import org.apache.commons.logging.LogFactory;
class="tags" href="/tags/IMPORT.html" title=import>import org.dozer.DozerBeanMapper;