前言

• 在 Java 系统工程开发过程中，都会有各个层之间的对象转换，比如 VO、DTO、PO、VO等。
• 如果都是手动get、set又太浪费时间，还可能操作错误，所以选择一个转换工具会更加方便。
• 整理出常见属性转换工具如下

Benchmark性能测试源码

• spring-base-demo/log-demo/src/test/java/org/gy/demo/log/BeanCopyTest.java at master · guanyang/spring-base-demo · GitHub

Benchmark性能测试对比

• 循环1000次性能数据

Benchmark                         (loop)   Mode  Cnt       Score       Error  Units
BeanCopyTest.apacheBeanCopy         1000  thrpt    5       5.444 ±     1.016  ops/s
BeanCopyTest.beanAsmBeanCopy        1000  thrpt    5    3207.672 ±   275.027  ops/s
BeanCopyTest.beanCopierBeanCopy     1000  thrpt    5   81902.789 ± 25799.131  ops/s
BeanCopyTest.beanMappingBeanCopy    1000  thrpt    5    1071.160 ±    40.030  ops/s
BeanCopyTest.dozerBeanCopy          1000  thrpt    5       2.715 ±     1.438  ops/s
BeanCopyTest.fastJsonBeanCopy       1000  thrpt    5     913.955 ±    93.294  ops/s
BeanCopyTest.getSetBeanCopy         1000  thrpt    5  108190.483 ± 11367.291  ops/s
BeanCopyTest.mapStructBeanCopy      1000  thrpt    5   98433.589 ±  9000.043  ops/s
BeanCopyTest.modelMapperBeanCopy    1000  thrpt    5     341.047 ±   213.611  ops/s
BeanCopyTest.orikaBeanCopy          1000  thrpt    5    2123.308 ±   413.037  ops/s
BeanCopyTest.springBeanCopy         1000  thrpt    5     404.477 ±   210.129  ops/s

• 循环10000次性能数据

Benchmark                         (loop)   Mode  Cnt      Score     Error  Units
BeanCopyTest.apacheBeanCopy        10000  thrpt    5      0.634 ±   0.075  ops/s
BeanCopyTest.beanAsmBeanCopy       10000  thrpt    5    341.249 ±  46.345  ops/s
BeanCopyTest.beanCopierBeanCopy    10000  thrpt    5  10140.338 ± 974.494  ops/s
BeanCopyTest.beanMappingBeanCopy   10000  thrpt    5    101.530 ±  48.186  ops/s
BeanCopyTest.dozerBeanCopy         10000  thrpt    5      0.335 ±   0.021  ops/s
BeanCopyTest.fastJsonBeanCopy      10000  thrpt    5    112.156 ±  11.229  ops/s
BeanCopyTest.getSetBeanCopy        10000  thrpt    5  11149.563 ± 831.699  ops/s
BeanCopyTest.mapStructBeanCopy     10000  thrpt    5  10504.837 ± 645.696  ops/s
BeanCopyTest.modelMapperBeanCopy   10000  thrpt    5     46.042 ±   1.786  ops/s
BeanCopyTest.orikaBeanCopy         10000  thrpt    5    218.724 ±  15.450  ops/s
BeanCopyTest.springBeanCopy        10000  thrpt    5     51.478 ±   6.783  ops/s

• 循环100000次性能数据

Benchmark                         (loop)   Mode  Cnt    Score     Error  Units
BeanCopyTest.apacheBeanCopy       100000  thrpt    5    0.071 ±   0.006  ops/s
BeanCopyTest.beanAsmBeanCopy      100000  thrpt    5   32.620 ±   3.874  ops/s
BeanCopyTest.beanCopierBeanCopy   100000  thrpt    5  646.601 ±  76.820  ops/s
BeanCopyTest.beanMappingBeanCopy  100000  thrpt    5   10.471 ±   2.635  ops/s
BeanCopyTest.dozerBeanCopy        100000  thrpt    5    0.029 ±   0.003  ops/s
BeanCopyTest.fastJsonBeanCopy     100000  thrpt    5    9.685 ±   1.250  ops/s
BeanCopyTest.getSetBeanCopy       100000  thrpt    5  571.465 ± 153.503  ops/s
BeanCopyTest.mapStructBeanCopy    100000  thrpt    5  441.470 ± 306.007  ops/s
BeanCopyTest.modelMapperBeanCopy  100000  thrpt    5    4.380 ±   0.950  ops/s
BeanCopyTest.orikaBeanCopy        100000  thrpt    5   18.668 ±   1.685  ops/s
BeanCopyTest.springBeanCopy       100000  thrpt    5    4.765 ±   2.302  ops/s

总结

• 对象属性转换的操作无非是基于反射、AOP、CGlib、ASM、Javassist在编译时和运行期进行处理，再有好的思路就是在编译前生成出对应的get、set，就像手写出来的一样。
• property少，写起来也不麻烦，就直接用传统的getter/setter，性能最好。
• property多，转换很频繁，建议直接用MapStruct，编译时生成get、set方法，性能最优。
• 如果不习惯用MapStruct，其次建议用BeanCopier，性能跟MapStruct接近，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。