JAVA对象拷贝 — Interge自动转Long？效率比拼

前言

今天开发中遇到一个小问题。
因为前期沟通不到位。有同学把一个后台接口（用于获取ES中的商品数据）的id相关字段，都设置成了Interge。而我们公司ID的要求是Long。

这导致数据后期维护十分不方便。还容易出错，举个例子
因为泛型擦除所以并不会报错且iidMap真实返回类型是Map<Interge, ItemTO>。导致调用iidMap.containsKey时用Long型是永远取不到的。

因为是Dubbo服务已经暴露出去。。。不太好收口。后期会废弃使用新的接口。临时的方案，准备用代理层，进行对象的拷贝。

那么我们问题就变成如下2个问题

1：如何选择JAVA Bean的Copy方式
2：Interge要能自动转化为Long

先把备的拷贝思路罗列出来

 1. 手工编码
 2. 动态代理
 3. Spring反射
 4. 序列化  

有了思路，那我开搞，顺道学习和复习总结一下JAVA对象的拷贝。
其中序列化方式，在这里其实是可行的。首先后台的量级不大，操作也方便，也能进行Interge和Long的转换。相对的序列化有明显的性能瓶颈，在大量操作时性能下降的特别快。

抱着好奇，我们一并探究并验证下手工编码，动态代理，Spring反射具体性能如何？能否转换Interge和Long？

有了相关的思路，网上也找了一下文章，自己动手实现一下
具体代码基本结构参考三石雨的文章大家可以看看

先看运行结果

5中方式的效率如图所示。
效率来说：
手写 > 动态代理 > 反射

 1. ManualCopy: 手动编写，效率最高，能类型转换，代码量多
 2. Cglib：动态代理，效率高，不能进行类型转换
 3. Apache Bean Utils , 反射，比较耗时，能进行类型转换
 4. Spring Bean Utils ：反射中等耗时，不能进行类型住哪换
 5. Apache Property Utils : 反射 类型不同，直接报错。

代码结构

来看看代码结构。

• Bean 源数据和目标数据（其中id类型不同）
• Process类（策略模式）
• 各类CopyMethod
• PerformanceTest 单测类
  

依赖

        <dependency>
            <groupId>cglib</groupId>
            <artifactId>cglib</artifactId>
            <version>3.2.2</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>5.2.5.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>commons-beanutils</groupId>
            <artifactId>commons-beanutils</artifactId>
            <version>1.9.2</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-beans</artifactId>
            <version>5.2.5.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>

Bean

SourceBean :id为Integer

package com.lctest.demo.lctrain.JavaBeanCopyTest.TO;

import com.fasterxml.jackson.annotation.JsonProperty;
import lombok.Getter;
import lombok.Setter;

import java.util.Map;

/**
 * SourceBean :id为Integer
 *
 * @author xiwen.chen
 * @since 2020-05-06
 */
@Setter
@Getter
public class SourceBean {

    private Integer iid;

    @JsonProperty("gmt_create")
    private Integer gmtCreate;

    private String name;

    @JsonProperty("actor_map")
    private Map<String, String> actorMap;
}

DestBean：对应Source的id 变为 Long型

package com.lctest.demo.lctrain.JavaBeanCopyTest.TO;

import com.fasterxml.jackson.annotation.JsonProperty;
import lombok.Getter;
import lombok.Setter;

import java.util.Map;

/**
 * DestBean：对应Source的id  变为 Long型
 *
 * @author xiwen.chen
 * @since 2020-05-06
 */
@Setter
@Getter
public class DestBean {

    private Long iid;

    @JsonProperty("gmt_create")
    private Long gmtCreate;

    private String name;

    @JsonProperty("actor_map")
    private Map<String, String> actorMap;
}

Process类（策略模式)

package com.lctest.demo.lctrain.JavaBeanCopyTest;

import com.lctest.demo.lctrain.JavaBeanCopyTest.TO.DestBean;
import com.lctest.demo.lctrain.JavaBeanCopyTest.TO.SourceBean;

/**
 * desc
 *
 * @author xiwen.chen
 * @since 2020-05-06
 */
public class CopyProcessor {

    private int count;

    public CopyProcessor(int count) {
        this.count = count;
        System.out.println("性能测试=======" + this.count + "===========");
    }

    public void process(CopyMethod methodCallBack, SourceBean sourceBean) throws Exception {
        long processBegin = System.currentTimeMillis();
        DestBean destBean = null;
        System.out.println(methodCallBack.getMethodName() + "测试开始！");

        for (int i = 0; i < count; i++) {
            destBean = methodCallBack.beanCopy(sourceBean);
        }

        long processEnd = System.currentTimeMillis();
        long timeConsuming = processEnd - processBegin;
        System.out.println(methodCallBack.getMethodName() + "测试结束！共耗时" + timeConsuming + "毫秒，copy结果如下:");

        System.out.println(destBean.getName());
        System.out.println(destBean.getIid());
        System.out.println(destBean.getActorMap());
        System.out.println(destBean.getGmtCreate());
        System.out.println("=============================================");
    }
}

单测类

package com.lctest.demo.lctrain.JavaBeanCopyTest;

import com.lctest.demo.lctrain.JavaBeanCopyTest.TO.SourceBean;
import com.lctest.demo.lctrain.JavaBeanCopyTest.copymethod.ApacheBeanUtilsCopy;
import com.lctest.demo.lctrain.JavaBeanCopyTest.copymethod.ApachePropertyUtilsCopy;
import com.lctest.demo.lctrain.JavaBeanCopyTest.copymethod.CglibCopy;
import com.lctest.demo.lctrain.JavaBeanCopyTest.copymethod.ManualCopy;
import com.lctest.demo.lctrain.JavaBeanCopyTest.copymethod.SpringBeanUtilsCopy;
import org.junit.Before;
import org.junit.Test;

import java.util.HashMap;
import java.util.Map;

/**
 * desc
 *
 * @author xiwen.chen
 * @since 2020-05-06
 */
public class PerformanceTest {

    private SourceBean sourceBean = null;

    private ManualCopy manualCopy = null;

    private CglibCopy cglibCopy = null;

    private ApacheBeanUtilsCopy apacheBeanUtilsCopy = null;

    private ApachePropertyUtilsCopy apachePropertyUtilsCopy = null;

    private SpringBeanUtilsCopy springBeanUtilsCopy = null;

    @Before
    public void init() {
        sourceBean = new SourceBean();
        sourceBean.setIid(445939013);
        sourceBean.setGmtCreate(1588694400);
        sourceBean.setName("xiwen copy bean test");
        Map<String, String> actorName = new HashMap<>();
        actorName.put("name1", "惜文");
        actorName.put("name2", "荣荣");
        actorName.put("name3", "新新");
        sourceBean.setActorMap(actorName);

        manualCopy = new ManualCopy();
        cglibCopy = new CglibCopy();
        apacheBeanUtilsCopy = new ApacheBeanUtilsCopy();
        apachePropertyUtilsCopy = new ApachePropertyUtilsCopy();
        springBeanUtilsCopy = new SpringBeanUtilsCopy();
    }

    @Test
    public void performTest10000() throws Exception {
        CopyProcessor copyProcessor = new CopyProcessor(10000);

        copyProcessor.process(apacheBeanUtilsCopy, sourceBean);
        copyProcessor.process(manualCopy, sourceBean);
        copyProcessor.process(cglibCopy, sourceBean);
        copyProcessor.process(springBeanUtilsCopy, sourceBean);
        copyProcessor.process(apachePropertyUtilsCopy, sourceBean);
    }
}

CopyMethod 5个具体实现类

接口

package com.lctest.demo.lctrain.JavaBeanCopyTest;

import com.lctest.demo.lctrain.JavaBeanCopyTest.TO.DestBean;
import com.lctest.demo.lctrain.JavaBeanCopyTest.TO.SourceBean;

/**
 * desc
 *
 * @author xiwen.chen
 * @since 2020-05-06
 */
public interface CopyMethod {

    public String getMethodName();

    public DestBean beanCopy(SourceBean sourceBean) throws Exception;
}

实现类

public class ManualCopy implements CopyMethod {

    @Override
    public String getMethodName() {
        return "manual copy";
    }

    @Override
    public DestBean beanCopy(SourceBean sourceBean) throws Exception {
        DestBean destBean = new DestBean();

        destBean.setActorMap(sourceBean.getActorMap());
        destBean.setGmtCreate(sourceBean.getGmtCreate().longValue());
        destBean.setIid(sourceBean.getIid().longValue());
        destBean.setName(sourceBean.getName());

        return destBean;
    }
}

public class SpringBeanUtilsCopy implements CopyMethod {

    @Override
    public String getMethodName() {
        return "Spring Bean Utils";
    }

    @Override
    public DestBean beanCopy(SourceBean sourceBean) throws Exception {
        DestBean destBean = new DestBean();
        BeanUtils.copyProperties(sourceBean, destBean);

        return destBean;
    }
}

public class CglibCopy implements CopyMethod {

    private BeanCopier beanCopier = BeanCopier.create(SourceBean.class, DestBean.class, false);

    @Override
    public String getMethodName() {
        return "Cglib BeanCopier";
    }

    @Override
    public DestBean beanCopy(SourceBean sourceBean) throws Exception {
        DestBean destBean = new DestBean();
        beanCopier.copy(sourceBean, destBean, null);
        return destBean;
    }
}

public class ApachePropertyUtilsCopy implements CopyMethod {

    @Override
    public String getMethodName() {
        return "Apache Property Utils";
    }

    @Override
    public DestBean beanCopy(SourceBean sourceBean) throws Exception {
        DestBean destBean = new DestBean();

        PropertyUtils.copyProperties(destBean, sourceBean);
        return destBean;
    }
}

public class ApacheBeanUtilsCopy implements CopyMethod {

    @Override
    public String getMethodName() {
        return "Apache Bean Utils";
    }

    @Override
    public DestBean beanCopy(SourceBean sourceBean) throws Exception {
        DestBean destBean = new DestBean();
        BeanUtils.copyProperties(destBean, sourceBean);
        return destBean;
    }
}

好了，得到结论，那我要开始手写了转换了。。。(:з」∠)~~