全局配置
方式一：yml 配置
spring:
jackson:
#日期格式化
date-format: yyyy-MM-dd HH:mm:ss
time-zone: GMT+8
#设置空如何序列化
default-property-inclusion: non_null
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方式二：重新注入 ObjectMapper
@Configuration
public class JacksonConfig {
// 修改 Jackson2ObjectMapperBuilder 的属性，设置时间类型序列化和反序列化的格式
@Bean
public Jackson2ObjectMapperBuilderCustomizer customizer() {
return builder -> {
builder.locale(Locale.CHINA);
builder.timeZone(TimeZone.getTimeZone(ZoneId.systemDefault()));
builder.simpleDateFormat("yyyy-MM-dd HH:mm:ss");
JavaTimeModule javaTimeModule = new JavaTimeModule();
javaTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
javaTimeModule.addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
javaTimeModule.addSerializer(LocalTime.class, new LocalTimeSerializer(DateTimeFormatter.ofPattern("HH:mm:ss")));
javaTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")));
javaTimeModule.addDeserializer(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ofPattern("yyyy-MM-dd")));
javaTimeModule.addDeserializer(LocalTime.class, new LocalTimeDeserializer(DateTimeFormatter.ofPattern("HH:mm:ss")));
builder.modules(javaTimeModule);
};
}
// 修改 ObjectMapper 的属性，设置自定义的序列化配置
@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
// Include.NON_NULL 属性为NULL 不序列化
objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
// 允许出现特殊字符和转义符
objectMapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_CONTROL_CHARS, true);
// 允许出现单引号
objectMapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
// 字段保留，将null值转为""
objectMapper.getSerializerProvider().setNullValueSerializer(new JsonSerializer<Object>()
{
@Override
public void serialize(Object o, JsonGenerator jsonGenerator,
SerializerProvider serializerProvider)
throws IOException
{
jsonGenerator.writeString("");
}
});
SimpleModule simpleModule = new SimpleModule();
/**
* 将Long,BigInteger序列化的时候,转化为String
*/
simpleModule.addSerializer(Long.class, ToStringSerializer.instance);
simpleModule.addSerializer(Long.TYPE, ToStringSerializer.instance);
simpleModule.addSerializer(BigInteger.class, ToStringSerializer.instance);
objectMapper.registerModule(simpleModule);
return objectMapper;
}
}局部配置
@JsonProperty
类似于 SQL 里字段的别名，用于序列化，使用注解字段属性，替代原字段属性
@JsonProperty("userName")
private String name;@JsonIgnore
在序列化时忽略该字段
@JsonIgnore
private Long id;@JsonIgnoreProperties
与 @JsonIgnore 类似，用于类上，注解使用的是字段别名
@JsonIgnoreProperties({"id","userName","birthday"})
public class User {
private Long id;
@JsonProperty("userName")
private String name;
private Integer age;
private Date birthday;
}序列化结果
{"age":23}@JsonTypeName @JsonTypeInfo
用在类上，在序列化时增加一层
@JsonTypeName(value = "user")
@JsonTypeInfo(include = JsonTypeInfo.As.WRAPPER_OBJECT, use = JsonTypeInfo.Id.NAME)
public class User {
private Long id;
@JsonProperty("userName")
private String name;
private Integer age;
private Date birthday;
}序列化结果
{"user":{"id":1,"age":23,"birthday":1587891781603,"userName":"tom"}}@JsonRootName
定义一个根 key
@JsonRootName(value = "user")
public class User {
private String id;
}使用时必须给 ObjectMapper 对象做如下设置
objectMapper.enable(SerializationFeature.WRAP_ROOT_VALUE);
objectMapper.enable(DeserializationFeature.UNWRAP_ROOT_VALUE);序列化结果
{"user": {"id": 1}}@JsonFormat
格式化日期格式
@JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss:SSS", timezone = "GMT+8")
private Date birthday;工具类
@Slf4j
public class JsonUtils {
private static ObjectMapper mapper = new ObjectMapper();
static {
// 对于空的对象转json的时候不抛出错误
mapper.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS);
// 允许属性名称没有引号
mapper.configure(JsonParser.Feature.ALLOW_UNQUOTED_FIELD_NAMES, true);
// 允许单引号
mapper.configure(JsonParser.Feature.ALLOW_SINGLE_QUOTES, true);
// 设置输入时忽略在json字符串中存在但在java对象实际没有的属性
mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
// 设置输出时包含属性的风格
mapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);
}
/**
* 序列化，将对象转化为json字符串
*
* @param data
* @return
*/
public static String toJsonString(Object data) {
if (data == null) {
return null;
}
String json = null;
try {
json = mapper.writeValueAsString(data);
} catch (JsonProcessingException e) {
log.error("[{}] toJsonString error：{{}}", data.getClass().getSimpleName(), e);
}
return json;
}
/**
* 反序列化，将json字符串转化为对象
*
* @param json
* @param clazz
* @param <T>
* @return
*/
public static <T> T parse(@NonNull String json, Class<T> clazz) {
T t = null;
try {
t = mapper.readValue(json, clazz);
} catch (Exception e) {
log.error(" parse json [{}] to class [{}] error：{{}}", json, clazz.getSimpleName(), e);
}
return t;
}
}Reference