Java jackson常用注解汇总 - ToB企服应用市场:ToB评测及商务社交产业平台

package org.example;
import com.fasterxml.jackson.annotation.JsonProperty;
public class PersonProperty {
@JsonProperty("first_name")
private String firstName;
public PersonProperty() {
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
}
---
public static void jsonPropertyDemo() {
ObjectMapper objectMapper = new ObjectMapper();
PersonProperty pp = new PersonProperty();
pp.setFirstName("Alice");
String jsonString = null;
try {
jsonString = objectMapper.writeValueAsString(pp);
System.out.println("json property: " + jsonString);
} catch (Exception e) {
e.printStackTrace();
}
try {
PersonProperty pp1 = objectMapper.readValue(jsonString, PersonProperty.class);
System.out.println(pp1.getFirstName());
} catch (Exception e) {
e.printStackTrace();
}
}
---

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package org.example;
import com.fasterxml.jackson.annotation.JsonPropertyOrder;
// {"name":"Bob","id":"111","age":25,"phone":"12345678910"}
@JsonPropertyOrder({"name", "id", "age", "phone"})
// 没有定义顺序，就按照字典序排列，{"age":25,"id":"111","name":"Bob","phone":"12345678910"}
// @JsonPropertyOrder(alphabetic = true)
public class PersonPropertyOrder {
private String id;
private String name;
private int age;
private String phone;
public PersonPropertyOrder() {
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getPhone() {
return phone;
}
public void setPhone(String phone) {
this.phone = phone;
}
}
---
public static void jsonPropertyOrder() {
ObjectMapper objectMapper = new ObjectMapper();
PersonPropertyOrder ppo = new PersonPropertyOrder();
ppo.setAge(25);
ppo.setId("111");
ppo.setName("Bob");
ppo.setPhone("12345678910");
String jsonString = null;
try {
jsonString = objectMapper.writeValueAsString(ppo);
System.out.println("json property: " + jsonString);
} catch (Exception e) {
e.printStackTrace();
}
}
---

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package org.example;
import com.fasterxml.jackson.annotation.JsonAlias;
public class PersonAlias {
@JsonAlias({"firstName", "personName"})
private String name;
public PersonAlias() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
---
public static void jsonAlias() {
String jsonString1 = "{"name":"Bob"}";
String jsonString2 = "{"firstName":"Bob"}";
String jsonString3 = "{"personName":"Bob"}";
ObjectMapper objectMapper = new ObjectMapper();
try {
PersonAlias p1 = objectMapper.readValue(jsonString1, PersonAlias.class);
PersonAlias p2 = objectMapper.readValue(jsonString2, PersonAlias.class);
PersonAlias p3 = objectMapper.readValue(jsonString3, PersonAlias.class);
System.out.printf("p1: %s, p2: %s, p3: %s", p1.getName(),p2.getName(), p3.getName());
} catch (Exception e) {
e.printStackTrace();
}
}
---

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package org.example;
import com.fasterxml.jackson.annotation.JsonIgnore;
public class PersonIgnore {
private String name;
@JsonIgnore // 不将其序列化，忽略该字段
private String[] hobbies;
public PersonIgnore() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String[] getHobbies() {
return hobbies;
}
public void setHobbies(String[] hobbies) {
this.hobbies = hobbies;
}
}
---
public static void jsonIgnore() {
ObjectMapper objectMapper = new ObjectMapper();
String jsonString = null;
try {
PersonIgnore pi = new PersonIgnore();
pi.setName("Cathy");
pi.setHobbies(null);
jsonString = objectMapper.writeValueAsString(pi);
System.out.println(jsonString);
} catch (Exception e) {
e.printStackTrace();
}
}
---

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package org.example;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
@JsonIgnoreProperties({"age"})
public class PersonIgnoreProperties {
private String name = "Alice";
private int age;
public PersonIgnoreProperties() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
---
public static void jsonIgnoreProperties() {
ObjectMapper objectMapper = new ObjectMapper();
PersonIgnoreProperties pip = new PersonIgnoreProperties();
pip.setName("Bob");
pip.setAge(18);
try {
String jsonString = objectMapper.writeValueAsString(pip);
System.out.println(jsonString);
} catch (Exception e) {
e.printStackTrace();
}
}
---

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package org.example;
import com.fasterxml.jackson.annotation.JsonInclude;
@JsonInclude(JsonInclude.Include.NON_NULL)
public class PersonInclude {
private int id;
private String name;
@JsonInclude(JsonInclude.Include.NON_NULL)
private String[] hobbies;
public PersonInclude() {
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String[] getHobbies() {
return hobbies;
}
public void setHobbies(String[] hobbies) {
this.hobbies = hobbies;
}
}
---
public static void jsonInclude() {
ObjectMapper objectMapper = new ObjectMapper();
PersonInclude pi = new PersonInclude();
pi.setName("Cathy");
pi.setId(1111);
try {
String jsonString = objectMapper.writeValueAsString(pi);
System.out.println(jsonString);
} catch (Exception e) {
e.printStackTrace();
}
}
---

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package org.example;
import com.fasterxml.jackson.annotation.JsonFormat;
import java.time.LocalDate;
import java.util.Date;
public class PersonFormat {
@JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd hh:mm:ss", timezone = "GMT+8")
private Date birthDate;
public PersonFormat() {
}
public Date getBirthDate() {
return birthDate;
}
public void setBirthDate(Date birthDate) {
this.birthDate = birthDate;
}
}
---
public static void jsonFormat() {
ObjectMapper objectMapper = new ObjectMapper();
PersonFormat pf = new PersonFormat();
pf.setBirthDate(new Date());
try {
String jsonString = objectMapper.writeValueAsString(pf);
System.out.println(jsonString);
} catch (Exception e) {
e.printStackTrace();
}
}
---

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package org.example;
import com.fasterxml.jackson.annotation.JacksonInject;
import java.time.LocalDate;
import java.time.LocalDateTime;
public class PersonInject {
private String name;
private int age;
@JacksonInject("responseTime")
private LocalDateTime responseTime;
public PersonInject() {
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public LocalDateTime getResponseTime() {
return responseTime;
}
public void setResponseTime(LocalDateTime responseTime) {
this.responseTime = responseTime;
}
}
---
public static void jsonInject() {
InjectableValues.Std iv = new InjectableValues.Std();
ObjectMapper objectMapper = new ObjectMapper();
iv.addValue("responseTime", LocalDateTime.now());
//将JSON字符串反序列化为java对象
String jsonString = "{"name":"Alice","age":23}";
objectMapper.setInjectableValues(iv);
try {
PersonInject pi = objectMapper.readValue(jsonString, PersonInject.class);
System.out.println(pi.getResponseTime());
} catch (Exception e) {
e.printStackTrace();
}
}
---

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package org.example;
import com.fasterxml.jackson.annotation.JsonCreator;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.databind.ObjectMapper;
public class PersonCreator {
private String name;
private int age;
// 构造方法1
public PersonCreator(String name) {
this.name = name;
}
// 构造方法2
@JsonCreator // 用于反序列化时的处理
public PersonCreator(@JsonProperty("username") String name,
@JsonProperty("age") int age) {
this.name = name;
this.age = age;
}
@Override
public String toString() {
return "Test{" +
"name='" + name + ''' +
", age='" + age + ''' +
'}';
}
public static void main(String[] args) throws Exception {
String jsonString = "{"username": "Alice", "age": 18}"; // username -> name
ObjectMapper objectMapper = new ObjectMapper();
try {
PersonCreator pc = objectMapper.readValue(jsonString, PersonCreator.class);
System.out.println(pc);
} catch (Exception e) {
e.printStackTrace();
}
}
}

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package org.example;
import com.fasterxml.jackson.databind.ObjectMapper;
import java.beans.ConstructorProperties;
public class PersonConstructorProperties {
private String username;
private int age;
public PersonConstructorProperties(String username) {
this.username = username;
}
@ConstructorProperties({"name", "age"})
public PersonConstructorProperties(String username, int age) {
System.out.println("全参构造函数...");
this.username = username;
this.age = age;
}
@Override
public String toString() {
return "Test{" +
"username='" + username + ''' +
", age='" + age + ''' +
'}';
}
public static void main(String[] args) {
String jsonString = "{"name": "Bob", "age": 29}";
ObjectMapper objectMapper = new ObjectMapper();
try {
PersonConstructorProperties pcp = objectMapper.readValue(jsonString, PersonConstructorProperties.class);
System.out.println(pcp);
} catch (Exception e) {
e.printStackTrace();
}
}
}

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package org.example;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import java.io.IOException;
import java.math.RoundingMode;
import java.text.DecimalFormat;
public class PersonSerialize {
@JsonSerialize(using = CustomDoubleSerialize.class, nullsUsing = NullNumberSerialize.class)
private Double model;
@JsonSerialize(nullsUsing = NullNumberSerialize.class)
private Double business;
private String name;
public PersonSerialize() {
}
public Double getModel() {
return model;
}
public void setModel(Double model) {
this.model = model;
}
public Double getBusiness() {
return business;
}
public void setBusiness(Double business) {
this.business = business;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
/**
* Double保留4位小数，输出string
*/
class CustomDoubleSerialize extends JsonSerializer<Double> {
private static final DecimalFormat df = new DecimalFormat("#.####");
@Override
public void serialize(Double value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
df.setRoundingMode(RoundingMode.HALF_UP); // 4
gen.writeString(df.format(value));
}
}
/**
* 任意类型null值，改为空字符串输出
*/
class NullNumberSerialize extends JsonSerializer<Object> {
@Override
public void serialize(Object value, JsonGenerator gen, SerializerProvider serializers) throws IOException {
gen.writeString("");
}
}
---
public static void jsonSerialize() {
ObjectMapper objectMapper = new ObjectMapper();
PersonSerialize ps = new PersonSerialize();
ps.setName("Alice");
ps.setModel(1.2345678);
try {
String jsonString = objectMapper.writeValueAsString(ps);
System.out.println(jsonString); // {"model":"1.2346","business":"","name":"Alice"}
} catch (Exception e) {
e.printStackTrace();
}
}
---

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package org.example;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.JsonDeserializer;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import java.io.IOException;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.time.format.FormatStyle;
public class PersonDeserialize {
@JsonSerialize(using = LocalDatetimeSerialize.class)
@JsonDeserialize(using = LocalDatetimeDeserialize.class)
private LocalDateTime birthDate;
private String name;
public PersonDeserialize() {
}
public LocalDateTime getBirthDate() {
return birthDate;
}
public void setBirthDate(LocalDateTime birthDate) {
this.birthDate = birthDate;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
}
class LocalDatetimeSerialize extends JsonSerializer<LocalDateTime> {
static final DateTimeFormatter DATE_FORMATTER = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM);
@Override
public void serialize(LocalDateTime value, JsonGenerator gen, SerializerProvider provider) throws IOException {
String str = value.format(DATE_FORMATTER);
gen.writeString(str);
}
}
class LocalDatetimeDeserialize extends JsonDeserializer<LocalDateTime> {
@Override
public LocalDateTime deserialize(JsonParser p, DeserializationContext ctx) throws IOException {
String str = p.getText();
return LocalDateTime.parse(str, LocalDatetimeSerialize.DATE_FORMATTER);
}
}
---
public static void jsonDeserialize() {
ObjectMapper objectMapper = new ObjectMapper();
PersonDeserialize pd = new PersonDeserialize();
pd.setName("Dav");
pd.setBirthDate(LocalDateTime.of(2000, 12, 5, 0, 0));
String jsonString = null;
// serialize
try {
jsonString = objectMapper.writeValueAsString(pd);
System.out.println(jsonString); // {"birthDate":"2000年12月5日 00:00:00","name":"Dav"}
} catch (Exception e) {
e.printStackTrace();
}
// deserialize
try {
PersonDeserialize pd1 = objectMapper.readValue(jsonString, PersonDeserialize.class);
// person -> name: Dav, birthdate: 2000-12-05T00:00
System.out.printf("person -> name: %s, birthdate: %s\n", pd1.getName(), pd1.getBirthDate());
} catch (Exception e) {
e.printStackTrace();
}
}
---

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package org.example;
import com.fasterxml.jackson.annotation.JsonAnyGetter;
import com.fasterxml.jackson.annotation.JsonAnySetter;
import java.util.HashMap;
import java.util.Map;
public class PersonGetAndSet {
private String username;
private String pwd;
private int age;
// @JsonAnySetter // 加方法或者属性都可以，但1个即可
private Map<String, String> map;
public PersonGetAndSet() {
this.map = new HashMap<>();
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@JsonAnyGetter // serialize, {"username":"Ada","pwd":"123456","age":26,"key1":"val1","key2":"val2"}
public Map<String, String> getMap() {
return map;
}
@JsonAnySetter // deserialize, pwd: 123456, age: 26, map: {key1=val1, key2=val2}
public void setMap(String key, String value) {
this.map.put(key, value);
}
}
---
public static void jsonGetterAndSetter() {
PersonGetAndSet pgs = new PersonGetAndSet();
pgs.setUsername("Ada");
pgs.setAge(26);
pgs.setPwd("123456");
pgs.setMap("key1", "val1");
pgs.setMap("key2", "val2");
ObjectMapper objectMapper = new ObjectMapper();
String jsonString = null;
try {
jsonString = objectMapper.writeValueAsString(pgs);
System.out.println(jsonString);
} catch (Exception e) {
e.printStackTrace();
}
try {
PersonGetAndSet pgs1 = objectMapper.readValue(jsonString, PersonGetAndSet.class);
System.out.printf("person -> username: %s, pwd: %s, age: %d, map: %s\n", pgs1.getUsername(), pgs1.getPwd(), pgs1.getAge(), pgs1.getMap());
} catch (Exception e) {
e.printStackTrace();
}
}
---

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package org.example;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.PropertyNamingStrategy;
import com.fasterxml.jackson.databind.annotation.JsonNaming;
//@JsonNaming(value = PropertyNamingStrategy.SnakeCaseStrategy.class) // 蛇形体：{"first_name":"Matt","second_name":"Damon"}
//@JsonNaming(value = PropertyNamingStrategy.UpperCamelCaseStrategy.class) // {"FirstName":"Matt","SecondName":"Damon"}
//@JsonNaming(value = PropertyNamingStrategy.LowerCaseStrategy.class) // {"firstname":"Matt","secondname":"Damon"}
@JsonNaming(value = PropertyNamingStrategy.LowerDotCaseStrategy.class) // {"first.name":"Matt","second.name":"Damon"}
public class PersonNaming {
private String firstName;
private String secondName;
public PersonNaming() {
}
public PersonNaming(String firstName, String secondName) {
this.firstName = firstName;
this.secondName = secondName;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getSecondName() {
return secondName;
}
public void setSecondName(String secondName) {
this.secondName = secondName;
}
public static void main(String[] args) {
PersonNaming pn = new PersonNaming();
pn.setFirstName("Matt");
pn.setSecondName("Damon");
ObjectMapper objectMapper = new ObjectMapper();
try {
String jsonString = objectMapper.writeValueAsString(pn);
System.out.println(jsonString);
} catch (Exception e) {
e.printStackTrace();
}
}
}

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