默认情况下，空字段也会被输出，我们可以使用@JsonInclude 不输出空字段。
package shangbo.jackson.demo10;import mons.lang3.builder.ToStringBuilder;import com.fasterxml.jackson.annotation.JsonInclude;@JsonInclude(JsonInclude.Include.NON_EMPTY)public class Person {private String firstname;private String lastname;public String toString() {return ToStringBuilder.reflectionToString(this);}public String getFirstname() {return firstname;}public void setFirstname(String firstname) {this.firstname = firstname;}public String getLastname() {return lastname;}public void setLastname(String lastname) {this.lastname = lastname;}}
package shangbo.jackson.demo10;import com.fasterxml.jackson.databind.ObjectMapper;public class App {public static void main(String[] args) throws Exception {// 实例化 ObjectMapper 对象ObjectMapper objectMapper = new ObjectMapper();// 将对象转成 jsonString json = objectMapper.writeValueAsString(newPerson());System.out.println(json);}private static Person newPerson() {Person shangbo = new Person();shangbo.setFirstname("Bo");//shangbo.setLastname("Shang");return shangbo;}}
原文链接：/shangboerds/article/details/90548743
