Bean拷贝工具类性能比较

港控/mmm° 2022-02-19 05:07 304阅读 0赞

## Bean拷贝工具类性能比较 ##

### 引言 ###

几年前做过一个项目，接入新的api接口。为了和api实现解耦，决定将api返回的实体类在本地也建一个。这样做有两个好处

1.  可以在api变更字段的时候保持应用稳定性
2.  可以对返回的实体的属性做处理，以提高可读性。例如接口返回long类型的时间戳，则将该字段在本地实体类中对应字段设置为date类型方便使用。

大致是这样的一个应用场景。当时刚毕业，充斥的都是A.setName(B.getName)这种类型的代码。当字段非常多的时候看起来非常臃肿，最重要的给人感觉不优雅。

### 再给我一次机会 ###

如果上天再给我一次机会，我会跟他说，我有四种工具类可以优雅的解决这个问题。  
分别是

*  org.apache.commons.beanutils.PropertyUtils.copyProperties
 *  org.apache.commons.beanutils.BeanUtils.copyProperties
 *  org.springframework.beans.BeanUtils.copyProperties
 *  net.sf.cglib.beans.BeanCopier

### Talk is cheap, show me code ###

定义SourceBean

package com.zhaoyangwoo.model;
    
    /**
     * Created by john on 16/7/28.
     */
     
    public class SourceBean {
    
        private Integer age;
    
        private String title;
        
        private String source;
    
        private Boolean eat;
        
        public SourceBean(Integer i, String name, Boolean eat, String source) {
            this.age = i;
            this.title = name;
            this.eat = eat;
            this.source = source;
        }
    
        public void setAge(Integer age) {
            this.age = age;
        }
    
        public String getTitle() {
            return title;
        }
    
        public void setTitle(String title) {
            this.title = title;
        }
    
        public Boolean getEat() {
            return eat;
        }
    
        public void setEat(Boolean eat) {
            this.eat = eat;
        }
    
        public String getSource() {
            return source;
        }
    
        public void setSource(String source) {
            this.source = source;
        }
    
        public Integer getAge() {
            return age;
        }
    
    }

定义DesBean

package com.zhaoyangwoo.model;
    
    /**
     * Created by john on 16/7/28.
     */
     
    public class DstBean {
    
        private Integer age;
    
        private String title;
    
        private Boolean eat;
    
        private String self;
    
        public String getSelf() {
            return self;
        }
    
        public void setSelf(String self) {
            this.self = self;
        }
    
        public Integer getAge() {
            return age;
        }
    
        public void setAge(Integer age) {
            this.age = age;
        }
    
        public String getTitle() {
            return title;
        }
    
        public void setTitle(String title) {
            this.title = title;
        }
    
        public Boolean getEat() {
            return eat;
        }
    
        public void setEat(Boolean eat) {
            this.eat = eat;
        }
    }

测试函数

package com.zhaoyangwoo.biz;
    
    import com.zhaoyangwoo.model.DstBean;
    import com.zhaoyangwoo.model.SourceBean;
    import net.sf.cglib.beans.BeanCopier;
    
    /**
     * Created by john on 16/7/28.
     */
    public class BeanCopyMain {
    
    private static BeanCopier beanCopier = BeanCopier.create(SourceBean.class, DstBean.class, false);
    
    
        public static void main(String[] args) throws Exception {
    
            Integer[] times = {10000, 1000, 10};
    
            for (int i = 0; i < times.length; i++) {
    
                Integer time = times[i];
                doCopy(time, (x, y) -> org.apache.commons.beanutils.PropertyUtils.copyProperties(y, x), "org.apache.commons.beanutils.PropertyUtils.copyProperties");
                doCopy(time, (x, y) -> org.apache.commons.beanutils.BeanUtils.copyProperties(y, x), "org.apache.commons.beanutils.BeanUtils.copyProperties");
                doCopy(time, (x, y) -> org.springframework.beans.BeanUtils.copyProperties(y, x), "org.springframework.beans.BeanUtils.copyProperties");
                doCopy(time, (x, y) -> beanCopier.copy(x, y, null), "net.sf.cglib.beans.BeanCopier.copy");
                doCopy(time, (x, y) -> {
                    y.setEat(x.getEat());
                    y.setTitle(x.getTitle());
                    y.setAge(x.getAge());
                }, "getter/setter");
            }
        }
    
        static void doCopy(Integer time, BeanCopy beanCopy, String type) throws Exception {
            long startTime = System.currentTimeMillis();
            for (int j = 0; j < time; j++) {
                SourceBean sourceBean = new SourceBean(j, "source" + j, false, "abc");
                DstBean dstBean = new DstBean();
                beanCopy.copy(sourceBean, dstBean);
            }
            System.out.printf("执行%d次用时%dms---------%s%n", time, System.currentTimeMillis() - startTime, type);
        }
    
        interface BeanCopy {
            void copy(SourceBean from, DstBean to) throws Exception;
        }
    }

执行结果如下  
![944957-20160730234126388-2133895634.png][]

![944957-20160730234135325-1220026001.png][]

![944957-20160730234143856-1667894744.png][]

### 结论 ###

根据上面的运行结果，我们可以得出以下结论

*  property少，写起来也不麻烦，就直接用传统的getter/setter，性能最好
 *  property多，转换不频繁，那就省点事吧，使用org.apache.commons.beanutils.BeanUtils.copyProperties
 *  property多，转换很频繁，为性能考虑，使用net.sf.cglib.beans.BeanCopier.BeanCopier，性能近乎getter/setter。但是BeanCopier的创建时消耗较大，所以不要频繁创建该实体，最好的处理方式是静态化或者缓存起来。

[944957-20160730234126388-2133895634.png]: /images/20220219/8d3520f2469e412698f1ca54b7aee117.png
[944957-20160730234135325-1220026001.png]: /images/20220219/23fe27381a194658acf6ed67153a179b.png
[944957-20160730234143856-1667894744.png]: /images/20220219/f502ea45b64e4b47842b46a149335b48.png