我们一起聊聊对象与 Map 转换性能优化方案

Person person = new Person();
person.setAge(18);
person.setOpenid("123456");
person.setName("一安");
person.setSubName("公众号");

System.out.println(bean2Map(person));

public static Map<String, Object> bean2Map(Object object) {
    ObjectMapper objectMapper = new ObjectMapper();
    return objectMapper.convertValue(object, new TypeReference<Map<String, Object>>() {
    });
}

<!-- JMH核心代码 -->
<dependency>
    <groupId>org.openjdk.jmh</groupId>
    <artifactId>jmh-core</artifactId>
    <version>1.35</version>
</dependency>

<!-- JMH注解相关依赖 -->
<dependency>
    <groupId>org.openjdk.jmh</groupId>
    <artifactId>jmh-generator-annprocess</artifactId>
    <version>1.35</version>
</dependency>

@BenchmarkMode(Mode.Throughput)
@OutputTimeUnit(TimeUnit.SECONDS)
@State(Scope.Thread)
@Fork(1)
@Warmup(iterations = 5, time = 1)
@Measurement(iterations = 3, time = 1)
public class JsonJMHTest {


    @Benchmark
    public static Map<String, Object> bean2Map() {
        Person person = new Person();
        person.setAge(18);
        person.setOpenid("123456");
        person.setName("一安");
        person.setSubName("公众号");

        ObjectMapper objectMapper = new ObjectMapper();
        return objectMapper.convertValue(person, new TypeReference<Map<String, Object>>() {
        });
    }

    @Benchmark
    public static <T> T map2Bean() {
        Map<String, Object> map = new HashMap();
        map.put("age", 18);
        map.put("openid", "123456");
        map.put("name", "一安");
        map.put("subName", "公众号");

        ObjectMapper objectMapper = new ObjectMapper();
        return (T) objectMapper.convertValue(map, Person.class);
    }

    public static void main(String[] args) throws RunnerException {
        Options opt = new OptionsBuilder()
                .include(JsonJMHTest.class.getSimpleName())
                .build();
        new Runner(opt).run();
    }

# Fork: 1 of 1
# Warmup Iteration   1: 4121.577 ops/s
# Warmup Iteration   2: 10599.791 ops/s
# Warmup Iteration   3: 1945.716 ops/s
# Warmup Iteration   4: 7284.198 ops/s
# Warmup Iteration   5: 8161.620 ops/s
Iteration   1: 841.544 ops/s
Iteration   2: 25483.108 ops/s
Iteration   3: 70902.482 ops/s


Result "org.example.JsonJMHTest.map2Bean":
  32409.045 ±(99.9%) 648386.677 ops/s [Average]
  (min, avg, max) = (841.544, 32409.045, 70902.482), stdev = 35540.262
  CI (99.9%): [≈ 0, 680795.722] (assumes normal distribution)


# Run complete. Total time: 00:00:22

REMEMBER: The numbers below are just data. To gain reusable insights, you need to follow up on
why the numbers are the way they are. Use profilers (see -prof, -lprof), design factorial
experiments, perform baseline and negative tests that provide experimental control, make sure
the benchmarking environment is safe on JVM/OS/HW level, ask for reviews from the domain experts.
Do not assume the numbers tell you what you want them to tell.

Benchmark              Mode  Cnt      Score        Error  Units
JsonJMHTest.bean2Map  thrpt    3  80269.397 ±  61739.014  ops/s
JsonJMHTest.map2Bean  thrpt    3  32409.045 ± 648386.677  ops/s

@Getter
public enum ObjectMapperInstance {
    INSTANCE;
    private final ObjectMapper objectMapper = new ObjectMapper();
    ObjectMapperInstance() {
    }
}

# Fork: 1 of 1
# Warmup Iteration   1: 916836.618 ops/s
# Warmup Iteration   2: 2057459.265 ops/s
# Warmup Iteration   3: 1992614.947 ops/s
# Warmup Iteration   4: 524763.395 ops/s
# Warmup Iteration   5: 2463816.439 ops/s
Iteration   1: 2570659.849 ops/s
Iteration   2: 2557669.589 ops/s
Iteration   3: 2548610.266 ops/s


Result "org.example.JsonJMHTest.map2Bean":
  2558979.901 ±(99.9%) 202195.856 ops/s [Average]
  (min, avg, max) = (2548610.266, 2558979.901, 2570659.849), stdev = 11083.037
  CI (99.9%): [2356784.046, 2761175.757] (assumes normal distribution)


# Run complete. Total time: 00:00:30

REMEMBER: The numbers below are just data. To gain reusable insights, you need to follow up on
why the numbers are the way they are. Use profilers (see -prof, -lprof), design factorial
experiments, perform baseline and negative tests that provide experimental control, make sure
the benchmarking environment is safe on JVM/OS/HW level, ask for reviews from the domain experts.
Do not assume the numbers tell you what you want them to tell.

Benchmark              Mode  Cnt        Score          Error  Units
JsonJMHTest.bean2Map  thrpt    3  1107857.325 ± 19284117.404  ops/s
JsonJMHTest.map2Bean  thrpt    3  2558979.901 ±   202195.856  ops/s