public class User {

    private String name;

    private Integer age;

    private LocalDateTime birthday;

    private Date studyDate;

    private LocalDate workDate;
    
    private Calendar firstWorkDate;
    
    public static User buildOne(){
        User user=new User();
        LocalDateTime now=LocalDateTime.now();
        user.setWorkDate(now.plusYears(25).toLocalDate());
        user.setStudyDate(Date.from(now.plusYears(5).atZone(ZoneId.systemDefault()).toInstant()));
        user.setName("姓名-"+RandomUtil.randomString(5));
        user.setAge(RandomUtil.randomInt(0,100));
        user.setBirthday(now);
        user.setFirstWorkDate(Calendar.getInstance());
        return user;
    }
    
    //getter and setter...
}

@RestController
public class UserApplication {


    @GetMapping("/queryOne")
    public ResponseEntity<User> queryOne(){
        return ResponseEntity.ok(User.buildOne());
    }
}

public class User {

    private String name;

    private Integer age;

    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    private LocalDateTime birthday;

    private Date studyDate;

    private LocalDate workDate;

    private Calendar firstWorkDate;
    //getter and setter...
}

private void configureDateFormat(Jackson2ObjectMapperBuilder builder) {
    // We support a fully qualified class name extending DateFormat or a date
    // pattern string value
    String dateFormat = this.jacksonProperties.getDateFormat();
    if (dateFormat != null) {
        try {
            Class<?> dateFormatClass = ClassUtils.forName(dateFormat, null);
            builder.dateFormat((DateFormat) BeanUtils.instantiateClass(dateFormatClass));
        }
        catch (ClassNotFoundException ex) {
            SimpleDateFormat simpleDateFormat = new SimpleDateFormat(dateFormat);
            // Since Jackson 2.6.3 we always need to set a TimeZone (see
            // gh-4170). If none in our properties fallback to the Jackson's
            // default
            TimeZone timeZone = this.jacksonProperties.getTimeZone();
            if (timeZone == null) {
                timeZone = new ObjectMapper().getSerializationConfig().getTimeZone();
            }
            simpleDateFormat.setTimeZone(timeZone);
            builder.dateFormat(simpleDateFormat);
        }
    }
}

//User.java
public static User buildOne(){
    User user=new User();
    LocalDateTime now=LocalDateTime.now();
    user.setWorkDate(now.plusYears(25).toLocalDate());
    user.setStudyDate(Date.from(now.plusYears(5).atZone(ZoneId.systemDefault()).toInstant()));
    user.setName("姓名-"+RandomUtil.randomString(5));
    user.setAge(RandomUtil.randomInt(0,100));
    user.setBirthday(now);
    user.setFirstWorkDate(Calendar.getInstance());
    return user;
}

public class TimeTest {
    public static void main(String[] args) {
        LocalDateTime localDateTime=LocalDateTime.now();
        DateTimeFormatter dateTimeFormatter=DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
        System.out.println(localDateTime.format(dateTimeFormatter));
        System.out.println(LocalDateTime.now(ZoneId.of("GMT+0901")).format(dateTimeFormatter));
        System.out.println(LocalDateTime.now(ZoneId.of("GMT+09:01")).format(dateTimeFormatter));
    }
}

public class User {

    private String name;

    private Integer age;
    private Date nowDate;

    private LocalDateTime birthday;

    private Date studyDate;

    private LocalDate workDate;

    private Calendar firstWorkDate;

    //getter方法修饰符从public修改为private
    private String getName() {
        return name;
    }
    //other setter and getter
}

private void configurePropertyNamingStrategyField(Jackson2ObjectMapperBuilder builder, String fieldName) {
    // Find the field (this way we automatically support new constants
    // that may be added by Jackson in the future)
    Field field = ReflectionUtils.findField(PropertyNamingStrategy.class, fieldName,
                                            PropertyNamingStrategy.class);
    Assert.notNull(field, () -> "Constant named '" + fieldName + "' not found on "
                   + PropertyNamingStrategy.class.getName());
    try {
        builder.propertyNamingStrategy((PropertyNamingStrategy) field.get(null));
    }
    catch (Exception ex) {
        throw new IllegalStateException(ex);
    }
}

package com.fasterxml.jackson.databind;

//other import

public class PropertyNamingStrategy // NOTE: was abstract until 2.7
    implements java.io.Serializable
{
    /**
     * Naming convention used in languages like C, where words are in lower-case
     * letters, separated by underscores.
     * See {@link SnakeCaseStrategy} for details.
     *
     * @since 2.7 (was formerly called {@link #CAMEL_CASE_TO_LOWER_CASE_WITH_UNDERSCORES})
     */
    public static final PropertyNamingStrategy SNAKE_CASE = new SnakeCaseStrategy();

    /**
     * Naming convention used in languages like Pascal, where words are capitalized
     * and no separator is used between words.
     * See {@link PascalCaseStrategy} for details.
     *
     * @since 2.7 (was formerly called {@link #PASCAL_CASE_TO_CAMEL_CASE})
     */
    public static final PropertyNamingStrategy UPPER_CAMEL_CASE = new UpperCamelCaseStrategy();

    /**
     * Naming convention used in Java, where words other than first are capitalized
     * and no separator is used between words. Since this is the native Java naming convention,
     * naming strategy will not do any transformation between names in data (JSON) and
     * POJOS.
     *
     * @since 2.7 (was formerly called {@link #PASCAL_CASE_TO_CAMEL_CASE})
     */
    public static final PropertyNamingStrategy LOWER_CAMEL_CASE = new PropertyNamingStrategy();
    
    /**
     * Naming convention in which all words of the logical name are in lower case, and
     * no separator is used between words.
     * See {@link LowerCaseStrategy} for details.
     * 
     * @since 2.4
     */
    public static final PropertyNamingStrategy LOWER_CASE = new LowerCaseStrategy();

    /**
     * Naming convention used in languages like Lisp, where words are in lower-case
     * letters, separated by hyphens.
     * See {@link KebabCaseStrategy} for details.
     * 
     * @since 2.7
     */
    public static final PropertyNamingStrategy KEBAB_CASE = new KebabCaseStrategy();

    /**
     * Naming convention widely used as configuration properties name, where words are in
     * lower-case letters, separated by dots.
     * See {@link LowerDotCaseStrategy} for details.
     *
     * @since 2.10
     */
    public static final PropertyNamingStrategy LOWER_DOT_CASE = new LowerDotCaseStrategy();
    
    //others...
}

/**
* Jackson general purpose on/off features.
*/
private final Map<MapperFeature, Boolean> mapper = new EnumMap<>(MapperFeature.class);

/**
 * Enumeration that defines simple on/off features to set
 * for {@link ObjectMapper}, and accessible (but not changeable)
 * via {@link ObjectReader} and {@link ObjectWriter} (as well as
 * through various convenience methods through context objects).
 *<p>
 * Note that in addition to being only mutable via {@link ObjectMapper},
 * changes only take effect when done <b>before any serialization or
 * deserialization</b> calls -- that is, caller must follow
 * "configure-then-use" pattern.
 */
public enum MapperFeature implements ConfigFeature
{
    //.......
}

/**
* Jackson on/off features that affect the way Java objects are serialized.
*/
private final Map<SerializationFeature, Boolean> serialization = new EnumMap<>(SerializationFeature.class);

/**
* Jackson on/off features that affect the way Java objects are deserialized.
 */
private final Map<DeserializationFeature, Boolean> deserialization = new EnumMap<>(DeserializationFeature.class);

//User.java
//指定value级别是CUSTOM
@JsonInclude(value = JsonInclude.Include.CUSTOM, valueFilter = StringFilter.class)
private String name;

//自定义非空判断规则
public class StringFilter {
    @Override
    public boolean equals(Object other) {
        if (other == null) {
            // Filter null's.
            return true;
        }

        // Filter "custom_string".
        return "custom_string".equals(other);
    }
}

@Configuration(proxyBeanMethods = false)
@ConditionalOnClass(ObjectMapper.class)
public class JacksonAutoConfiguration {

	private static final Map<?, Boolean> FEATURE_DEFAULTS;

	static {
		Map<Object, Boolean> featureDefaults = new HashMap<>();
		featureDefaults.put(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS, false);
		featureDefaults.put(SerializationFeature.WRITE_DURATIONS_AS_TIMESTAMPS, false);
		FEATURE_DEFAULTS = Collections.unmodifiableMap(featureDefaults);
	}

	@Bean
	public JsonComponentModule jsonComponentModule() {
		return new JsonComponentModule();
	}

	@Configuration(proxyBeanMethods = false)
	@ConditionalOnClass(Jackson2ObjectMapperBuilder.class)
	static class JacksonObjectMapperConfiguration {

		@Bean
		@Primary
		@ConditionalOnMissingBean
		ObjectMapper jacksonObjectMapper(Jackson2ObjectMapperBuilder builder) {
			return builder.createXmlMapper(false).build();
		}

	}

	@Configuration(proxyBeanMethods = false)
	@ConditionalOnClass(ParameterNamesModule.class)
	static class ParameterNamesModuleConfiguration {

		@Bean
		@ConditionalOnMissingBean
		ParameterNamesModule parameterNamesModule() {
			return new ParameterNamesModule(JsonCreator.Mode.DEFAULT);
		}

	}

	@Configuration(proxyBeanMethods = false)
	@ConditionalOnClass(Jackson2ObjectMapperBuilder.class)
	static class JacksonObjectMapperBuilderConfiguration {

		@Bean
		@Scope("prototype")
		@ConditionalOnMissingBean
		Jackson2ObjectMapperBuilder jacksonObjectMapperBuilder(ApplicationContext applicationContext,
				List<Jackson2ObjectMapperBuilderCustomizer> customizers) {
			Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();
			builder.applicationContext(applicationContext);
			customize(builder, customizers);
			return builder;
		}

		private void customize(Jackson2ObjectMapperBuilder builder,
				List<Jackson2ObjectMapperBuilderCustomizer> customizers) {
			for (Jackson2ObjectMapperBuilderCustomizer customizer : customizers) {
				customizer.customize(builder);
			}
		}

	}
    @Configuration(proxyBeanMethods = false)
	@ConditionalOnClass(Jackson2ObjectMapperBuilder.class)
	@EnableConfigurationProperties(JacksonProperties.class)
	static class Jackson2ObjectMapperBuilderCustomizerConfiguration {

		@Bean
		StandardJackson2ObjectMapperBuilderCustomizer standardJacksonObjectMapperBuilderCustomizer(
				ApplicationContext applicationContext, JacksonProperties jacksonProperties) {
			return new StandardJackson2ObjectMapperBuilderCustomizer(applicationContext, jacksonProperties);
		}

		static final class StandardJackson2ObjectMapperBuilderCustomizer
				implements Jackson2ObjectMapperBuilderCustomizer, Ordered {

			private final ApplicationContext applicationContext;

			private final JacksonProperties jacksonProperties;

			StandardJackson2ObjectMapperBuilderCustomizer(ApplicationContext applicationContext,
					JacksonProperties jacksonProperties) {
				this.applicationContext = applicationContext;
				this.jacksonProperties = jacksonProperties;
			}

			@Override
			public int getOrder() {
				return 0;
			}

			@Override
			public void customize(Jackson2ObjectMapperBuilder builder) {

				if (this.jacksonProperties.getDefaultPropertyInclusion() != null) {
					builder.serializationInclusion(this.jacksonProperties.getDefaultPropertyInclusion());
				}
				if (this.jacksonProperties.getTimeZone() != null) {
					builder.timeZone(this.jacksonProperties.getTimeZone());
				}
				configureFeatures(builder, FEATURE_DEFAULTS);
				configureVisibility(builder, this.jacksonProperties.getVisibility());
				configureFeatures(builder, this.jacksonProperties.getDeserialization());
				configureFeatures(builder, this.jacksonProperties.getSerialization());
				configureFeatures(builder, this.jacksonProperties.getMapper());
				configureFeatures(builder, this.jacksonProperties.getParser());
				configureFeatures(builder, this.jacksonProperties.getGenerator());
				configureDateFormat(builder);
				configurePropertyNamingStrategy(builder);
				configureModules(builder);
				configureLocale(builder);
			}

			//more configure methods...
	}
}

public class ExtendableBean {

    public String name;
    private Map<String, String> properties;

    @JsonAnyGetter
    public Map<String, String> getProperties() {
        return properties;
    }

    public ExtendableBean(String name) {
        this.name = name;
        this.properties=new HashMap<String, String>();
    }


    public void add(String key,String value){
        this.properties.put(key,value);
    }
}

@Test
public void whenSerializingUsingJsonAnyGetter_thenCorrect()
  throws JsonProcessingException {
 
    ExtendableBean bean = new ExtendableBean("My bean");
    bean.add("attr1", "val1");
    bean.add("attr2", "val2");

    String result = new ObjectMapper().writeValueAsString(bean);
 
    assertThat(result, containsString("attr1"));
    assertThat(result, containsString("val1"));
}

public class MyBean {
    public int id;
    private String name;

    @JsonGetter("name")
    public String getTheName() {
        return name;
    }
}

@JsonPropertyOrder({ "name", "id" })
public class MyBean {
    public int id;
    public String name;
}

public class RawBean {
    public String name;

    @JsonRawValue
    public String json;
}

 RawBean bean = new RawBean("My bean", "{\"attr\":false}");

String result = new ObjectMapper().writeValueAsString(bean);

public enum  TypeEnumWithValue {
    TYPE1(1, "Type A"), TYPE2(2, "Type 2");

    private Integer id;
    private String name;

    TypeEnumWithValue(Integer id, String name) {
        this.id = id;
        this.name = name;
    }

    @JsonValue
    public String getName() {
        return name;
    }
}

String enumAsString = new ObjectMapper()
                .writeValueAsString(TypeEnumWithValue.TYPE1);
System.out.println(enumAsString);

//RootUser.java
public class RootUser {

    private String name;
    private String title;

    public RootUser(String name, String title) {
        this.name = name;
        this.title = title;
    }
    
 	//getter and setters  
}

//RootUser.java
@JsonRootName(value = "root")
public class RootUser {

    private String name;
    private String title;

    public RootUser(String name, String title) {
        this.name = name;
        this.title = title;
    }
    
 	//getter and setters  
}

ObjectMapper objectMapper=new ObjectMapper();
objectMapper.enable(SerializationFeature.WRAP_ROOT_VALUE);
String result=objectMapper.writeValueAsString(new RootUser("name1","title1"));

public class EventWithSerializer {
    public String name;

    @JsonSerialize(using = CustomDateSerializer.class)
    public Date eventDate;
    
    public Date publishDate;
    
    //getter and setter...
}

//CustomDateSerializer.java
public class CustomDateSerializer extends StdSerializer<Date> {

    private static SimpleDateFormat formatter 
      = new SimpleDateFormat("dd-MM-yyyy hh:mm:ss");

    public CustomDateSerializer() { 
        this(null); 
    } 

    public CustomDateSerializer(Class<Date> t) {
        super(t); 
    }

    @Override
    public void serialize(
      Date value, JsonGenerator gen, SerializerProvider arg2) 
      throws IOException, JsonProcessingException {
        gen.writeString(formatter.format(value));
    }
}

public class BeanWithCreator {
    public int id;
    public String name;

    @JsonCreator
    public BeanWithCreator(
      @JsonProperty("id") int id, 
      @JsonProperty("theName") String name) {
        this.id = id;
        this.name = name;
    }
}

@Test
public void whenDeserializingUsingJsonCreator_thenCorrect()
  throws IOException {
 
    String json = "{\"id\":1,\"theName\":\"My bean\"}";

    BeanWithCreator bean = new ObjectMapper()
      .readerFor(BeanWithCreator.class)
      .readValue(json);
    assertEquals("My bean", bean.name);
}

public class BeanWithInject {
    @JacksonInject
    public int id;
    
    public String name;
}

@Test
public void whenDeserializingUsingJsonInject_thenCorrect()
  throws IOException {
 
    String json = "{\"name\":\"My bean\"}";
    
    InjectableValues inject = new InjectableValues.Std()
      .addValue(int.class, 1);
    BeanWithInject bean = new ObjectMapper().reader(inject)
      .forType(BeanWithInject.class)
      .readValue(json);
    
    assertEquals("My bean", bean.name);
    assertEquals(1, bean.id);
}

public class ExtendableBean {
    public String name;
    private Map<String, String> properties;

    @JsonAnySetter
    public void add(String key, String value) {
        properties.put(key, value);
    }
}

@Test
public void whenDeserializingUsingJsonAnySetter_thenCorrect()
  throws IOException {
    String json
      = "{\"name\":\"My bean\",\"attr2\":\"val2\",\"attr1\":\"val1\"}";

    ExtendableBean bean = new ObjectMapper()
      .readerFor(ExtendableBean.class)
      .readValue(json);
    
    assertEquals("My bean", bean.name);
    assertEquals("val2", bean.getProperties().get("attr2"));
}

public class MyBean {
    public int id;
    private String name;

    @JsonSetter("name")
    public void setTheName(String name) {
        this.name = name;
    }
}

@Test
public void whenDeserializingUsingJsonSetter_thenCorrect()
  throws IOException {
 
    String json = "{\"id\":1,\"name\":\"My bean\"}";

    MyBean bean = new ObjectMapper()
      .readerFor(MyBean.class)
      .readValue(json);
    assertEquals("My bean", bean.getTheName());
}

public class EventWithSerializer {
    public String name;

    @JsonDeserialize(using = CustomDateDeserializer.class)
    public Date eventDate;
}

public class CustomDateDeserializer
  extends StdDeserializer<Date> {

    private static SimpleDateFormat formatter
      = new SimpleDateFormat("dd-MM-yyyy hh:mm:ss");

    public CustomDateDeserializer() { 
        this(null); 
    } 

    public CustomDateDeserializer(Class<?> vc) { 
        super(vc); 
    }

    @Override
    public Date deserialize(
      JsonParser jsonparser, DeserializationContext context) 
      throws IOException {
        
        String date = jsonparser.getText();
        try {
            return formatter.parse(date);
        } catch (ParseException e) {
            throw new RuntimeException(e);
        }
    }
}

@Test
public void whenDeserializingUsingJsonDeserialize_thenCorrect()
  throws IOException {
 
    String json
      = "{"name":"party","eventDate":"20-12-2014 02:30:00"}";

    SimpleDateFormat df
      = new SimpleDateFormat("dd-MM-yyyy hh:mm:ss");
    EventWithSerializer event = new ObjectMapper()
      .readerFor(EventWithSerializer.class)
      .readValue(json);
    
    assertEquals(
      "20-12-2014 02:30:00", df.format(event.eventDate));
}

public class AliasBean {
    @JsonAlias({ "fName", "f_name" })
    private String firstName;   
    private String lastName;
}

@Test
public void whenDeserializingUsingJsonAlias_thenCorrect() throws IOException {
    String json = "{\"fName\": \"John\", \"lastName\": \"Green\"}";
    AliasBean aliasBean = new ObjectMapper().readerFor(AliasBean.class).readValue(json);
    assertEquals("John", aliasBean.getFirstName());
}

@JsonIgnoreProperties({ "id" })
public class BeanWithIgnore {
    public int id;
    public String name;
}

public class BeanWithIgnore {
    @JsonIgnore
    public int id;

    public String name;
}

public class User {
    public int id;
    public Name name;

    @JsonIgnoreType
    public static class Name {
        public String firstName;
        public String lastName;
    }
}

@JsonInclude(Include.NON_NULL)
public class MyBean {
    public int id;
    public String name;
}

public class PrivateBean {
    private int id;
    private String name;

    public PrivateBean(int id, String name) {
        this.id = id;
        this.name = name;
    }
}

@JsonAutoDetect(fieldVisibility = JsonAutoDetect.Visibility.ANY)
public class PrivateBean {
    private int id;
    private String name;

    public PrivateBean(int id, String name) {
        this.id = id;
        this.name = name;
    }
}

PrivateBean bean = new PrivateBean(1, "My bean");
String result = new ObjectMapper().writeValueAsString(bean);
System.out.println(result);

public class MyBean {
    public int id;
    private String name;

    @JsonProperty("name")
    public void setTheName(String name) {
        this.name = name;
    }

    @JsonProperty("name")
    public String getTheName() {
        return name;
    }
}

public class EventWithFormat {
    public String name;

    @JsonFormat(
      shape = JsonFormat.Shape.STRING,
      pattern = "dd-MM-yyyy hh:mm:ss")
    public Date eventDate;
}

public class UnwrappedUser {
    public int id;

    @JsonUnwrapped
    public Name name;
    
    //getter and setter...

    public static class Name {
        public String firstName;
        public String lastName;
        //getter and setter
    }
}

UnwrappedUser.Name name = new UnwrappedUser.Name("John", "Doe");
UnwrappedUser user = new UnwrappedUser(1, name);

String result = new ObjectMapper().writeValueAsString(user);

public class Views {
    public static class Public {}
    public static class Internal extends Public {}
}

public class Item {
    @JsonView(Views.Public.class)
    public int id;

    @JsonView(Views.Public.class)
    public String itemName;

    @JsonView(Views.Internal.class)
    public String ownerName;
    //getter and setter..

}

Item item = new Item(2, "book", "John");

String result = new ObjectMapper().writerWithView(Views.Public.class).writeValueAsString(item);
System.out.println(result);