springboot2.3 @JsonFormat注解不生效 马虎造成(类未序列化)

请您多多留言指教(自己搭建springboot2.3.1+mybatisplus3.3.2)

注：以下为搭建项目并查找@JsonFormat注解不生效的几处关键位置

 

一、pom.xml引用Jackson依赖

    com.fasterxml.jackson.core
    jackson-core
    2.11.0


    com.fasterxml.jackson.core
    jackson-annotations
    2.11.0


    com.fasterxml.jackson.core
    jackson-databind
    2.11.0


    org.codehaus.jackson
    jackson-mapper-asl
    1.9.13

二、DAO类对象实体 @JsonFormat注解 

@TableName("t_company")
public class Company {
    @TableId(value = "id", type = IdType.ASSIGN_UUID)
    private String id;

    @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    @TableField(value = "created_at")
    private Date createdAt;

    @DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    @JsonFormat(pattern = "yyyy-MM-dd")
    @TableField(value = "updated_at")
    private Date updatedAt;

    ...其它属性字段省略
}

三、application.yml jackson全局配置

# jackson全局配置
  jackson:
    # 全局设置@JsonFormat的格式pattern
    date-format: yyyy-MM-dd HH:mm:ss
    # 当地时区
    locale: zh
    # 设置全局时区
    time-zone: GMT+8
    serialization:
      #格式化输出
      indent_output: true
#      #忽略无法转换的对象
#      fail_on_empty_beans: false
#    deserialization:
#      #允许对象忽略json中不存在的属性
#      fail_on_unknown_properties: false
    parser:
      #允许出现特殊字符和转义符
      allow_unquoted_control_chars: true
      #允许出现单引号
      allow_single_quotes: true
#    #如果加该注解的字段为null,那么就不序列化这个字段了
#    default-property-inclusion: NON_EMPTY

四、自定义Jackson配置 JacksonConfig类

import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializerProvider;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
import java.io.IOException;

@Configuration
public class JacksonConfig {
    /**
     * 重新注入ObjectMapper
     * 注：使用此方式ObjectMapper,application中Jackson自动失效
     *
     * @param builder
     * @return
     */
    @Bean
    @Primary
    @ConditionalOnMissingBean(ObjectMapper.class)
    public ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {
        ObjectMapper objectMapper = builder.createXmlMapper(false).build();

        // 通过该方法对mapper对象进行设置，所有序列化的对象都将按改规则进行系列化
        // Include.Include.ALWAYS 默认
        // Include.NON_DEFAULT 属性为默认值不序列化
        // Include.NON_EMPTY 属性为 空（""） 或者为 NULL 都不序列化，则返回的json是没有这个字段的。这样对移动端会更省流量
        // Include.NON_NULL 属性为NULL 不序列化
        objectMapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
        // 反序列化时 忽略匹配不到的属性字段
        objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
        // 允许出现单引号
        objectMapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
        // 字段保留，将null值转为""
        objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer