<!-- JMH -->
<dependency>
    <groupId>org.openjdk.jmh</groupId>
    <artifactId>jmh-core</artifactId>
    <version>${jmh.version}</version>
</dependency>
<dependency>
    <groupId>org.openjdk.jmh</groupId>
    <artifactId>jmh-generator-annprocess</artifactId>
    <version>${jmh.version}</version>
    <scope>provided</scope>
</dependency>

package com.xiaojiang;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;

import java.util.concurrent.TimeUnit;

/**
 * @ Description：jmh使用第一個(gè)例子
 * @ Author     ：xiaojiang
 * @ Date       ：Created in 2019-06-19
 * @ Version    ：0.0.1
 */
@OutputTimeUnit(TimeUnit.MILLISECONDS)
@BenchmarkMode(Mode.AverageTime)
public class JmhDemoOne {
    public static void main(String[] args) throws Exception{
        Options options = new OptionsBuilder()
                .include(JmhDemoOne.class.getName())
                .build();
        new Runner(options).run();
    }
    /**
     * 測(cè)試sayHello的平局耗時(shí)
     *
     * @throws Exception
     */
    @Benchmark
    public void sayHello() throws Exception{
        //TODO 業(yè)務(wù)方法 ，此處用休眠的方式模擬業(yè)務(wù)耗時(shí)10 ms
        TimeUnit.MILLISECONDS.sleep(10);
    }
}

# JMH version: 1.21
# VM version: JDK 1.8.0_144, Java HotSpot(TM) 64-Bit Server VM, 25.144-b01
# VM invoker: D:\Java\jdk1.8.0_144\jre\bin\java.exe
# VM options: -javaagent:D:\Program Files\JetBrains\IntelliJ IDEA 2018.2.5\lib\idea_rt.jar=55987:D:\Program Files\JetBrains\IntelliJ IDEA 2018.2.5\bin -Dfile.encoding=UTF-8
# Warmup: 5 iterations, 10 s each
# Measurement: 5 iterations, 10 s each
# Timeout: 10 min per iteration
# Threads: 1 thread, will synchronize iterations
# Benchmark mode: Average time, time/op
# Benchmark: com.xiaojiang.JmhDemoOne.sayHello

# Run progress: 0.00% complete, ETA 00:08:20
# Fork: 1 of 5
# Warmup Iteration   1: 10.716 ms/op
# Warmup Iteration   2: 10.640 ms/op
# Warmup Iteration   3: 10.737 ms/op
# Warmup Iteration   4: 10.693 ms/op
# Warmup Iteration   5: 10.723 ms/op
Iteration   1: 10.716 ms/op
Iteration   2: 10.724 ms/op
Iteration   3: 10.772 ms/op
Iteration   4: 10.758 ms/op
Iteration   5: 10.709 ms/op

# Run progress: 20.00% complete, ETA 00:06:43
# Fork: 2 of 5
# Warmup Iteration   1: 10.744 ms/op
# Warmup Iteration   2: 10.732 ms/op
# Warmup Iteration   3: 10.748 ms/op
# Warmup Iteration   4: 10.728 ms/op
# Warmup Iteration   5: 10.760 ms/op
Iteration   1: 10.701 ms/op
Iteration   2: 10.709 ms/op
Iteration   3: 10.719 ms/op
Iteration   4: 10.714 ms/op
Iteration   5: 10.703 ms/op

# Run progress: 40.00% complete, ETA 00:05:02
# Fork: 3 of 5
# Warmup Iteration   1: 10.729 ms/op
# Warmup Iteration   2: 10.731 ms/op
# Warmup Iteration   3: 10.728 ms/op
# Warmup Iteration   4: 10.700 ms/op
# Warmup Iteration   5: 10.709 ms/op
Iteration   1: 10.708 ms/op
Iteration   2: 10.701 ms/op
Iteration   3: 10.708 ms/op
Iteration   4: 10.726 ms/op
Iteration   5: 10.698 ms/op

# Run progress: 60.00% complete, ETA 00:03:21
# Fork: 4 of 5
# Warmup Iteration   1: 10.724 ms/op
# Warmup Iteration   2: 10.688 ms/op
# Warmup Iteration   3: 10.748 ms/op
# Warmup Iteration   4: 10.732 ms/op
# Warmup Iteration   5: 10.772 ms/op
Iteration   1: 10.729 ms/op
Iteration   2: 10.688 ms/op
Iteration   3: 10.705 ms/op
Iteration   4: 10.687 ms/op
Iteration   5: 10.709 ms/op

# Run progress: 80.00% complete, ETA 00:01:40
# Fork: 5 of 5
# Warmup Iteration   1: 10.688 ms/op
# Warmup Iteration   2: 10.696 ms/op
# Warmup Iteration   3: 10.692 ms/op
# Warmup Iteration   4: 10.684 ms/op
# Warmup Iteration   5: 10.683 ms/op
Iteration   1: 10.719 ms/op
Iteration   2: 10.720 ms/op
Iteration   3: 10.695 ms/op
Iteration   4: 10.710 ms/op
Iteration   5: 10.760 ms/op


Result "com.xiaojiang.JmhDemoOne.sayHello":
  10.716 ±(99.9%) 0.016 ms/op [Average]
  (min, avg, max) = (10.687, 10.716, 10.772), stdev = 0.021
  CI (99.9%): [10.700, 10.731] (assumes normal distribution)


# Run complete. Total time: 00:08:24

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
JmhDemoOne.sayHello  avgt   25  10.716 ± 0.016  ms/op

Process finished with exit code 0

Options options = new OptionsBuilder()
        .include(JmhDemoOne.class.getName())
        .output("D:/JmhDemoOne.log")   //將測(cè)試結(jié)果輸出到指定目錄文件
        .build();

package com.xiaojiang;

import org.openjdk.jmh.annotations.*;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;
import java.util.concurrent.TimeUnit;
/**
 * @ Description：jmh使用第二個(gè)例子
 * @ Author     ：xiaojiang
 * @ Date       ：Created in 2019-06-19
 * @ Version    ：0.0.1
 */
@OutputTimeUnit(TimeUnit.SECONDS)
@BenchmarkMode(Mode.Throughput)
@Warmup(iterations = 5, time = 1, timeUnit = TimeUnit.MILLISECONDS)
@Measurement(iterations = 10, time = 5, timeUnit = TimeUnit.SECONDS)
@State(Scope.Thread)
public class JmhDemoTwo {
    public static void main(String[] args) throws Exception{
        Options options = new OptionsBuilder()
                .include(JmhDemoTwo.class.getName())
                .build();
        new Runner(options).run();
    }
    /**
     * 字符串個(gè)數(shù)
     */
    @Param({"10", "100", "1000"})
    private int number;
    /**
     * 字符串直接相加方式
     */
    @Benchmark
    public void StringAddMode(){
        String str = "";
        for(int i=0;i<number;i++){
            str = str + i;
        }
    }
    /**
     * 字符串通過StringBuilder的append方式
     */
    @Benchmark
    public void StringBuilderMode(){
        StringBuilder sb = new StringBuilder();
        for(int i=0;i<number;i++){
            sb.append(i);
        }
    }
}

package com.xiaojiang;

import org.openjdk.jmh.annotations.*;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.concurrent.TimeUnit;
/**
 * @ Description：jmh使用第三個(gè)例子
 * @ Author     ：xiaojiang
 * @ Date       ：Created in 2019-06-19
 * @ Version    ：0.0.1
 */
@OutputTimeUnit(TimeUnit.MILLISECONDS)
@BenchmarkMode(Mode.SingleShotTime)
@Warmup(iterations = 5)
@Measurement(iterations = 1)
@State(Scope.Benchmark)
@Fork(1)
public class JmhDemoThree {
    public static void main(String[] args) throws Exception{
        Options options = new OptionsBuilder()
                .include(JmhDemoThree.class.getName())
                .build();
        new Runner(options).run();
    }
    /**
     * 序列化次數(shù)
     */
    @Param({"100", "10000", "1000000"})
    private int number;
    private Userinfo userinfo;
    private String fastjson_jsonStr;
    private String gson_jsonStr;
    private String jackson_jsonStr;
    /**
     *  fastjson bean2Json
     */
    @Benchmark
    public void fastjson_bean2Json(){
        for (int i=0;i<number;i++){
            JsonUtil.fastjson_bean2Json(userinfo);
        }
    }
    /**
     *  gson bean2Json
     */
    @Benchmark
    public void gson_bean2Json(){
        for (int i=0;i<number;i++){
            JsonUtil.gson_bean2Json(userinfo);
        }
    }
    /**
     *  jackson bean2Json
     */
    @Benchmark
    public void jackson_bean2Json(){
        for (int i=0;i<number;i++){
            JsonUtil.jackson_bean2Json(userinfo);
        }
    }
    /**
     *  fastjson json2Bean
     */
    @Benchmark
    public void fastjson_json2Bean(){
        for (int i=0;i<number;i++){
            JsonUtil.fastjson_json2Bean(fastjson_jsonStr,Userinfo.class);
        }
    }
    /**
     *  gson json2Bean
     */
    @Benchmark
    public void gson_json2Bean(){
        for (int i=0;i<number;i++){
            JsonUtil.gson_json2Bean(gson_jsonStr,Userinfo.class);
        }
    }
    /**
     *  jackson json2Bean
     */
    @Benchmark
    public void jackson_json2Bean(){
        for (int i=0;i<number;i++){
            JsonUtil.jackson_json2Bean(jackson_jsonStr,Userinfo.class);
        }
    }
    /**
     * 初始化參數(shù)
     */
    @Setup
    public void init(){
         userinfo = new Userinfo();
        userinfo.setUsername("張三");
        userinfo.setGender("男");
        userinfo.setAge(18);
        userinfo.setBirthday(new Date());
        userinfo.setCreateTime(System.currentTimeMillis());
        List<String> list = new ArrayList<>();
        list.add("北京三里屯兒那條街那條巷那一號(hào)");
        list.add("上海三里屯兒那條街那條巷那一號(hào)");
        list.add("深圳三里屯兒那條街那條巷那一號(hào)");
        userinfo.setAddress(list);
        
        fastjson_jsonStr = JsonUtil.fastjson_bean2Json(userinfo);
        gson_jsonStr = JsonUtil.gson_bean2Json(userinfo);
        jackson_jsonStr = JsonUtil.jackson_bean2Json(userinfo);
    }
}

<!--fastJson-->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>fastjson</artifactId>
    <version>1.2.58</version>
</dependency>
<!--gson-->
<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
    <version>2.8.5</version>
</dependency>
<!--jackson-->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.9.9</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.9.9</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
    <version>2.9.9</version>
</dependency>

package com.xiaojiang;

import java.util.Date;
import java.util.List;
/**
 * @ Description：用戶信息
 * @ Author     ：xiaojiang
 * @ Date       ：Created in 2019-06-19
 * @ Version    ：0.0.1
 */
public class Userinfo {
    private String username;    //用戶名
    private String gender;      //用戶性別
    private Integer age;    //用戶年齡
    private Date birthday;      //用戶生日
    private List<String> address;   //  用戶地址
    private Long createTime;    //用戶創(chuàng)建時(shí)間

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

    public Date getBirthday() {
        return birthday;
    }

    public void setBirthday(Date birthday) {
        this.birthday = birthday;
    }

    public List<String> getAddress() {
        return address;
    }

    public void setAddress(List<String> address) {
        this.address = address;
    }

    public Long getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Long createTime) {
        this.createTime = createTime;
    }

    @Override
    public String toString() {
        return "Userinfo{" +
                "username='" + username + '\'' +
                ", gender='" + gender + '\'' +
                ", age=" + age +
                ", birthday=" + birthday +
                ", address=" + address +
                ", createTime=" + createTime +
                '}';
    }
}

package com.xiaojiang;

import com.alibaba.fastjson.JSON;
import com.fasterxml.jackson.core.JsonProcessingException;

import java.io.IOException;

/**
 * @ Description：json工具類
 * @ Author     ：xiaojiang
 * @ Date       ：Created in 2019-06-19
 * @ Version    ：0.0.1
 */
public class JsonUtil {

    private static com.google.gson.Gson gson = new com.google.gson.GsonBuilder().create();
    private static com.fasterxml.jackson.databind.ObjectMapper jacksonMapper = new com.fasterxml.jackson.databind.ObjectMapper();

    public static String fastjson_bean2Json(Object object){
        return com.alibaba.fastjson.JSON.toJSONString(object);
    }

    public static <T> T fastjson_json2Bean(String jsonStr, Class<T> objectClass) {
        return JSON.parseObject(jsonStr, objectClass);
    }

    public static String gson_bean2Json(Object object){
        return gson.toJson(object);
    }

    public static <T> T gson_json2Bean(String jsonStr, Class<T> objectClass){
        return gson.fromJson(jsonStr,objectClass);
    }

    public static String jackson_bean2Json(Object object) {
        try {
            return jacksonMapper.writeValueAsString(object);
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        return null;
    }

    public static <T> T jackson_json2Bean(String jsonStr, Class<T> objectClass){
        try {
            return jacksonMapper.readValue(jsonStr,objectClass);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }
}