{
  "name": "張三",
  "age": 25,
  "email": "zhangsan@example.com"
}

// 必須有無(wú)參構(gòu)造函數(shù)
// 必須有為所有屬性生成的 Getter 和 Setter 方法
// lombok注解 自動(dòng)生成getter與setter方法與無(wú)參構(gòu)造函數(shù)
@Data 
public class User {
    private String name;
    private Integer age;
    private String email;
}

@RestController
public class UserController {
    @PostMapping("/users")
    public ResponseEntity<String> createUser(@RequestBody User user) { 
        // 在這個(gè)方法內(nèi)部，User 對(duì)象已經(jīng)是一個(gè)可以直接使用的 Java 對(duì)象了
        System.out.println("用戶(hù)名：" + user.getName());
        System.out.println("年齡：" + user.getage());
        // ... 保存用戶(hù)到數(shù)據(jù)庫(kù)等操作
        return ResponseEntity.ok("用戶(hù)創(chuàng)建成功");
    }
}

@RestController
public class UserController {
    @GetMapping("/users/{id}")
    public User getUser(@PathVariable Long id) {
        // 假設(shè)從數(shù)據(jù)庫(kù)或其他地方查詢(xún)到了一個(gè)用戶(hù)
        User user = new User();
        user.setName("李四");
        user.setAge(30);
        user.setEmail("lisi@example.com");
        // 直接返回這個(gè)對(duì)象
        return user;
    }
}

{
  "name": "李四",
  "age": 30,
  "email": "lisi@example.com"
}

public class User {
    private String name;
    @JsonIgnore // 返回給前端的 JSON 中不會(huì)包含 password 字段，保障安全
    private String password;
}

public class User {
    @JsonProperty("full_name") // 序列化后 JSON 中的 key 是 "full_name"
    private String name;
}

public class User {
    @JsonFormat(pattern = "yyyy-MM-dd HH:mm:ss")
    private Date createTime;
}

@JsonInclude(JsonInclude.Include.NON_NULL) // 只包含非 null 字段
public class User {
    private String name;
    private Integer age; // 如果 age 為 null，則序列化結(jié)果中無(wú)此字段
}

public class Views {
    public static class Public {} // 公共視圖
    public static class Internal extends Public {} // 內(nèi)部視圖，繼承公共視圖
}
public class User {
    @JsonView(Views.Public.class)
    private String name;
    @JsonView(Views.Internal.class)
    private String email;
}
@RestController
public class UserController {
    @GetMapping("/user/public")
    @JsonView(Views.Public.class) // 只序列化 Public 視圖的字段
    public User getPublicUser() { ... }
    @GetMapping("/user/internal")
    @JsonView(Views.Internal.class) // 序列化 Internal 和 Public 視圖的字段
    public User getInternalUser() { ... }
}

// 1. 自定義序列化器
public class MoneySerializer extends JsonSerializer<Money> {
    @Override
    public void serialize(Money value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
        // 將 Money 對(duì)象轉(zhuǎn)換為字符串
        String moneyStr = value.getAmount() + "元";
        gen.writeString(moneyStr);
    }
}
// 2. 自定義反序列化器
public class MoneyDeserializer extends JsonDeserializer<Money> {
    @Override
    public Money deserialize(JsonParser p, DeserializationContext ctxt) throws IOException {
        String text = p.getText(); // 例如 "100.00元"
        // 解析字符串，創(chuàng)建 Money 對(duì)象
        String amountStr = text.replace("元", "");
        BigDecimal amount = new BigDecimal(amountStr);
        return new Money(amount);
    }
}
// 3. 在 Money 類(lèi)上使用注解綁定
public class Money {
    private BigDecimal amount;
    @JsonSerialize(using = MoneySerializer.class)
    @JsonDeserialize(using = MoneyDeserializer.class)
    public BigDecimal getAmount() {
        return amount;
    }
}

# 縮進(jìn)輸出，便于閱讀
spring.jackson.serialization.indent-output=true
# 忽略未知屬性，反序列化時(shí)如果JSON有類(lèi)中沒(méi)有的字段不報(bào)錯(cuò)
spring.jackson.deserialization.fail-on-unknown-properties=false
# 日期全局格式
spring.jackson.date-format=yyyy-MM-dd HH:mm:ss
# 忽略值為 null 的字段
spring.jackson.default-property-inclusion=non_null

@Configuration
public class JacksonConfig {
    @Bean
    public Jackson2ObjectMapperBuilderCustomizer jacksonCustomizer() {
        return builder -> {
            builder.serializationInclusion(JsonInclude.Include.NON_NULL);
            builder.featuresToEnable(SerializationFeature.INDENT_OUTPUT);
            builder.featuresToDisable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
            builder.simpleDateFormat("yyyy-MM-dd HH:mm:ss");
        };
    }
}