maven依赖

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.10.0</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.10.0</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
    <version>2.10.0</version>
</dependency>

测试Bean

public class Bean {

  private Long id;

  private Long userId;

  public Bean(Long id, Long userId) {
    this.id = id;
    this.userId = userId;
  }

  public Bean() {
  }

  public Long getId() {
    return id;
  }

  public void setId(Long id) {
    this.id = id;
  }

  public Long getUserId() {
    return userId;
  }

  public void setUserId(Long userId) {
    this.userId = userId;
  }

  @Override
  public String toString() {
    return "Bean{" +
        "id=" + id +
        ", userId=" + userId +
        '}';
  }
}  

测试转换

public static void main(String[] args) {
    HashMap<String,Object> hashMap = new LinkedHashMap<>();
    hashMap.put("id",1);
    hashMap.put("userId",2);


    ObjectMapper mapper = new ObjectMapper();
    Bean bean = mapper.convertValue(hashMap, Bean.class);

    System.out.println(bean);
}