Java Jackson将字段序列化为不同的名称
我要反序列化这个JSON:Java Jackson将字段序列化为不同的名称,java,json,serialization,jackson,Java,Json,Serialization,Jackson,我要反序列化这个JSON: { "first-name": "Alpha", "last-name": "Beta", "gender": "m" } 我想将其序列化为两种不同的格式: [A] { "first-name": "Alpha", "last-name": "Beta", "gender": "m" } { "firstName": "Alpha", "lastName": "Beta", "gender":
{
"first-name": "Alpha",
"last-name": "Beta",
"gender": "m"
}
我想将其序列化为两种不同的格式:
[A]
{
"first-name": "Alpha",
"last-name": "Beta",
"gender": "m"
}
{
"firstName": "Alpha",
"lastName": "Beta",
"gender": "m"
}
[B]
{
"first-name": "Alpha",
"last-name": "Beta",
"gender": "m"
}
{
"firstName": "Alpha",
"lastName": "Beta",
"gender": "m"
}
我可以将其序列化为1种格式:[A]或[B]。下面是我将其序列化到[B]的代码:
public String firstName;
public String lastName;
public String gender;
@JsonProperty("firstName")
public String getFirstNameCC() {
return firstName;
}
@JsonProperty("first-name")
public void setFirstNameD(String firstName) {
this.firstName = firstName;
}
@JsonProperty("lastName")
public String getLastNameCC() {
return lastName;
}
@JsonProperty("last-name")
public void setLastNameD(String lastName) {
this.lastName = lastName;
}
public String getGender() {
return gender;
}
public void setGender(String gender) {
this.gender = gender;
}
我在这里读到了
JsonView
(第5节:定制JSON视图),但它只改变了它的值。我想更改字段名,如上例所示。有人能对此给出见解吗?我不确定我是否完全理解您的问题,但就我所能理解的而言,您可以这样做以实现不同的序列化
创建自定义批注以保存所有可能的不同序列化选项:
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface CustomJsonProperty {
String propertyName();
String format();
@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
@Documented
@interface List {
CustomJsonProperty[] value();
}
}
相应地为您的类添加注释:
@JsonSerialize(using = CustomJsonPropertySerializer.class)
public class Bar {
@CustomJsonProperty.List({
@CustomJsonProperty(propertyName = "first-name", format = "A"),
@CustomJsonProperty(propertyName = "firstName", format = "B")
})
private String firstName;
@CustomJsonProperty.List({
@CustomJsonProperty(propertyName = "last-name", format = "A"),
@CustomJsonProperty(propertyName = "lastName", format = "B")
})
private String lastName;
@CustomJsonProperty.List({
@CustomJsonProperty(propertyName = "gender-x", format = "A"),
@CustomJsonProperty(propertyName = "gender", format = "B")
})
private String gender;
@JsonIgnore
private String format;
//getters & setters
}
创建自定义序列化程序以解释新注释:
public class CustomJsonPropertySerializer extends JsonSerializer<Bar> {
@Override
public void serialize(Bar bar, JsonGenerator jsonGenerator, SerializerProvider serializerProvider)
throws IOException {
jsonGenerator.writeStartObject();
Field[] fields = bar.getClass().getDeclaredFields();
for (Field field : fields) {
field.setAccessible(true);
Object value = null;
try {
value = field.get(bar);
} catch (IllegalAccessException e) {
e.printStackTrace();
}
if (field.isAnnotationPresent(CustomJsonProperty.List.class)) {
CustomJsonProperty[] properties = field.getAnnotation(CustomJsonProperty.List.class).value();
CustomJsonProperty chosenProperty = null;
for (CustomJsonProperty c : properties) {
if (c.format().equalsIgnoreCase(bar.getFormat())) {
chosenProperty = c;
break;
}
}
if (chosenProperty == null) {
//invalid format given, use first format then
chosenProperty = properties[0];
}
jsonGenerator.writeStringField(chosenProperty.propertyName(), value.toString());
}
}
jsonGenerator.writeEndObject();
}
}
输出:
{"first-name":"first","last-name":"last","gender-x":"m"}
{"firstName":"first","lastName":"last","gender":"m"}
当然,上面的序列化程序只适用于Bar对象,但这可以通过使用继承抽象字符串getFormat()轻松解决代码>并更改自定义序列化程序以接受超类类型,而不是Bar
也许有一个简单的方法比创造你自己的东西,但我不知道。如果有什么不清楚的地方,请告诉我,我可以再详细说明。有一种更简单的方法可以做到这一点-创建一个使用“addMixin”函数的objectmapper
要序列化的类:
Class YouWantToSerializeMe {
public String firstName;
public String lastName;
public String gender;
@JsonProperty("firstName")
public String getFirstNameCC() {
return firstName;
}
@JsonProperty("lastName")
public String getLastNameCC() {
return lastName;
}
}
现在,要同时使用内置字段名和自定义字段名进行序列化,可以执行以下操作:
Class DoTheSerializing {
String serializeNormally(YouWantToSerializeMe me) {
ObjectMapper objectMapper = new ObjectMapper();
ObjectWriter objectWriter = objectMapper.writer();
return objectWriter(me)
}
String serializeWithMixin(YouWantToSerializeMe me) {
ObjectMapper objectMapper = new ObjectMapper();
ObjectWriter objectWriter = objectMapper
.addMixIn(YouWantToSerializeMe.class, MyMixin.class)
.writer();
return objectWriter(me)
}
interface MyMixin {
@JsonProperty("first-name")
public String getFirstNameCC();
@JsonProperty("last-name")
public String getLastNameCC();
}
}
这在类中使用了一个嵌入式接口来保持事物的局部性。您可以围绕此进行大量优化,例如创建静态ObjectMapper和加载/卸载mixin
使用接口作为“模板”来控制映射功能非常强大。您可以在字段和类级别添加内容 几个星期以来,我一直在寻找解决这个问题的办法。但大多数解决方案都很模糊,不够灵活。在这方面,我认为这更为简洁和恰当。