JAVA基于mapper文件实现异构对象转换

由于最近公司订单系统数据库重构，上游的交易系统也要重构，所以有大量的异构对象转换工作，所以要求做一个通用的基于配置的复杂对象转换。 主要需求为：假设有A、B两个对象，需要实现 A的属性名和B的属性名不一致， A的子对象和B的子对象不一致， A的子对象是一个LIST和B的子对象LIST不一致， A的某个属性转换为B的属性需要简单的计算， 无限递归，也就是A和B所具有的的子对象层数不确定。 经过研究，发现了一个非常好使的转换工具，DOZER。

---

需要依赖的JAR包

<dependency>
    <groupId>dozer</groupId>
    <artifactId>dozer</artifactId>
    <version>5.3.2</version>
</dependency>
<dependency>
    <groupId>commons-beanutils</groupId>
    <artifactId>commons-beanutils</artifactId>
    <version>1.9.2</version>
</dependency><dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>${slf4j.version}</version>
</dependency>
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>${slf4j.version}</version>
</dependency>

---

核心配置文件

dept:
<?xml version="1.0" 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">
    <configuration>
        <stop-on-errors>true</stop-on-errors>
        <date-format>yyyy-MM-dd hh:mm:ss</date-format>
        <wildcard>true</wildcard>
        <custom-converters>
            <converter type="com.dbtest.common.MyCustomConverter">
                <class-a>java.lang.Enum</class-a>
                <class-b>java.lang.Integer</class-b>
            </converter>
        </custom-converters>
    </configuration>
    <mapping>
        <class-a>com.dbtest.entity.SourceDept</class-a>
        <class-b>com.dbtest.entity.TargetDept</class-b>
        <field>
            <a>deptName</a>
            <b>name</b>
        </field>
        <field>
            <a>deptId</a>
            <b>newId</b>
        </field>
        <field map-id="User">
            <a>sourceUserList</a>
            <b>targetUserList</b>
            <a-hint>com.dbtest.entity.SourceUser</a-hint>
            <b-hint>com.dbtest.entity.TargetUser</b-hint>
        </field>
    </mapping>
</mappings>
USER:
<?xml version="1.0" 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 map-id="User">
        <class-a>com.dbtest.entity.SourceUser</class-a>
        <class-b>com.dbtest.entity.TargetUser</class-b>
        <field>
            <a>name</a>
            <b>userName</b>
        </field>
        <field map-id="Info">
            <a>sourceInfoList</a>
            <b>targetInfoList</b>
            <a-hint>com.dbtest.entity.SourceInfo</a-hint>
            <b-hint>com.dbtest.entity.TargetInfo</b-hint>
        </field>
    </mapping>
</mappings>
INFO:
<?xml version="1.0" 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 map-id="Info">
        <class-a>com.dbtest.entity.SourceInfo</class-a>
        <class-b>com.dbtest.entity.TargetInfo</class-b>
        <field>
            <a>createDate</a>
            <b>date</b>
        </field>
        <field>
            <a>gender</a>
            <b>gender</b>
        </field>
        <field>
            <a>id</a>
            <b>id</b>
        </field>
    </mapping>
</mappings>

---

集成SPRING

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="
    http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
    http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd
    http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.1.xsd"
    default-autowire="byName" default-lazy-init="false">
 
    <bean id="beanMapper" class="org.dozer.spring.DozerBeanMapperFactoryBean">
        <property name="mappingFiles">
            <list>
                <value>conf/mapper/*.xml</value>
            </list>
        </property>
    </bean>
</beans>

---

计算实现

    <field custom-converter="com.dbtest.common.MyCustomConverter">
            <a>gender</a>
            <b>gender</b>
        </field>
转换类：
/**
 * 自定义转换类
 * 
 * @author spd
 * @create 2013-3-28 下午2:49:39
 */
public class MyCustomConverter implements CustomConverter {
 
    @Override
    public Object convert(Object existingDestinationFieldValue,
            Object sourceFieldValue, Class<?> destinationClass,
            Class<?> sourceClass) {
        Object obj = null;
        if (null != sourceFieldValue) {
            if (sourceFieldValue.equals(GenderType.male))
                obj = 1;
            else
                obj = 2;
 
        }
        return obj;
    }
}