cnmade / tamper

A Java Bean to Java Bean mapper that recursively copies data from one object to another

Introduction

tamper是一款处理bean/map进行属性复制映射的工具，支持递归，集合等深度映射.

Why need tamper

这里列觉了几种需要使用tamper的场景：

• model 和 DO的转化 (DO = Data Object , 数据库对象的设计是一种大宽表的设计，domain/model的设计，会有层次结构&具体)。 比如表设计存储会采用json存储动态数据，而在model中会是具体的属性
• model 和 VO的转化 (VO = View Object , 公司的产品detail页面，涉及了后端n多个domain/model的组合展示，这时候会进行包装成VO，包装一些页面组装逻辑)
• model 和 DTO的转化 (DTO = Data Transfer Object ，公司子系统比较多，系统之间会有比较多的rpc等remote调用)
• form -> bean的转化 (现在流行的几个MVC框架，都已经开始支持view层的参数注入，比如@Paramter(name="field")String , @Form("name=xx")Bean)。 提交的form表单数据，基本都是以map+list为主，就会涉及一个mapping

Why tamper

• 解决BeanUtils, BeanCopier?使用上的局限，只能针对同名属性的拷贝
• 相比于BeanUtils，性能提升是它的优势
• 相比于BeanCopier，类型之间的convertor是它的优势
• 支持插件方式的扩展，自身框架的设计也是基于插件扩展。

目前的插件支持：

• default value支持
• convetor转换
• script脚本支持 (EL表达式处理)
• bean creator(嵌套对象自动创建)

Maven repository

<dependency>
   <groupId>com.alibaba.tamper</groupId>
   <artifactId>tamper</artifactId>
   <version>1.0.3</version>
</dependency>

FAQ

1.How to import to eclipse by maven?

  mvn eclipse:eclipse

2.How to build project by maven?

  mvn clean package

3.How to run testcase by maven?

  mvn test

Example1：

自定义映射规则，处理bean/map <-> bean/map

Step 1 (define mapping config)

bean-mappings xmlns="https://github.com/alibaba/tamper/schema/mapping" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="https://github.com/alibaba/tamper/schema/mapping https://raw.github.com/alibaba/tamper/master/src/main/resources/META-INF/mapping.xsd">
        <!--  (bean-bean) mapping 测试 -->
        <bean-mapping batch="true" srcClass="com.agapple.mapping.object.SrcMappingObject" targetClass="com.agapple.mapping.object.TargetMappingObject" reversable="true">
            <field-mapping srcName="intValue" targetName="intValue" />
            <field-mapping targetName="integerValue" script="src.intValue + src.integerValue" /> <!-- 测试script -->
            <field-mapping srcName="start" targetName="start" />
            <field-mapping srcName="name" targetName="targetName" /> <!--  注意不同名 -->
            <field-mapping srcName="mapping" targetName="mapping" mapping="true" />
        </bean-mapping>
    &lt;bean-mapping batch="true" srcClass="com.agapple.mapping.object.NestedSrcMappingObject" targetClass="com.agapple.mapping.object.NestedTargetMappingObject" reversable="true"&gt;
        &lt;field-mapping srcName="name" targetName="name" defaultValue="ljh" /&gt; &lt;!-- 测试default value --&gt;
        &lt;field-mapping srcName="bigDecimalValue" targetName="value" targetClass="string" defaultValue="10" /&gt; &lt;!-- 测试不同名+不同类型+default value  --&gt;
    &lt;/bean-mapping&gt;

&lt;/bean-mappings&gt;</pre>

Step 2 (do mapping) 
public BeanMapping srcMapping    = BeanMapping.create(SrcMappingObject.class, TargetMappingObject.class);
public BeanMapping targetMapping = BeanMapping.create(TargetMappingObject.class , SrcMappingObject.class);
@Test
public void testBeanToBean_ok() {
    SrcMappingObject srcRef = new SrcMappingObject();
    srcRef.setIntegerValue(1);
    srcRef.setIntValue(1);
    srcRef.setName("ljh");
    srcRef.setStart(true);

    TargetMappingObject targetRef = new TargetMappingObject();// 测试一下mapping到一个Object对象
    srcMapping.mapping(srcRef, targetRef);

    SrcMappingObject newSrcRef = new SrcMappingObject();// 反过来再mapping一次
    targetMapping.mapping(targetRef, newSrcRef);
}</pre>

Example2： 
类似于BeanUtils/BeanCopier，根据同名属性进行自动映射，不需要定义任何的mapping.xml
public BeanCopy srcCopy    = BeanCopy.create(SrcMappingObject.class, TargetMappingObject.class);
    public BeanCopy targetCopy = BeanCopy.create(TargetMappingObject.class , SrcMappingObject.class);
@Test
public void testBeanToBean_ok() {
    SrcMappingObject srcRef = new SrcMappingObject();
    srcRef.setIntegerValue(1);
    srcRef.setIntValue(1);
    srcRef.setName("ljh");
    srcRef.setStart(true);

    TargetMappingObject targetRef = new TargetMappingObject();// 测试一下mapping到一个Object对象
    srcCopy.copy(srcRef, targetRef);

    SrcMappingObject newSrcRef = new SrcMappingObject();// 反过来再mapping一次
    targetCopy.copy(targetRef, newSrcRef);
}</pre>

Example3： 
类似于BeanUtils，处理map<->bean
 public BeanMap beanMap = BeanMap.create(SrcMappingObject.class);

    @Test
    public void testDescribe_Populate_ok() {
        SrcMappingObject srcRef = new SrcMappingObject();
        srcRef.setIntegerValue(1);
        srcRef.setIntValue(1);
        srcRef.setName("ljh");
        srcRef.setStart(true);
    Map map = beanMap.describe(srcRef);

    SrcMappingObject newSrcRef = new SrcMappingObject();// 反过来再mapping一次
    beanMap.populate(newSrcRef, map);
}</pre>

Example4：
Mapping API定义映射
BeanMappingBuilder builder = new BeanMappingBuilder() {
        protected void configure() {
            mapping(HashMap.class, HashMap.class).batch(false).reversable(true).keys("src", "target");
            fields(srcField("one"), targetField("oneOther")).convertor("convertor").defaultValue("ljh");
            fields(srcField("two").clazz(String.class), targetField("twoOther")).script("1+2").convertor(
                                                                                                         StringToCommon.class);
            fields(srcField("three").clazz(ArrayList.class), targetField("threeOther").clazz(HashSet.class)).recursiveMapping(
                                                                                                                              true);
        }

    };</pre>

通过builder可以比较方便的构造mapping config，最后需要生成mapping实例，还需要做一步： 
BeanMapping mapping = new BeanMapping(builder);
mapping.mapping(src, dest);//使用
or  
BeanMappingConfigHelper.getInstance().register(builder); // 进行注册
BeanMappingObject object = BeanMappingConfigHelper.getInstance().getBeanMappingObject(srcClass,targetClass);
mapping.mapping(src, dest);//使用

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