是否可能:在类中有一个字段，但在Jackson库中序列化/反序列化期间为它取不同的名称?
例如，我有一个类“coordindiantes”。
class Coordinates{
int red;
}
对于JSON的反序列化，希望有这样的格式:
{
"red":12
}
但是当我序列化对象时，结果应该是这样的:
{
"r":12
}
我试图通过在getter和setter上应用@JsonProperty注释来实现这一点(具有不同的值):
class Coordiantes{
int red;
@JsonProperty("r")
public byte getRed() {
return red;
}
@JsonProperty("red")
public void setRed(byte red) {
this.red = red;
}
}
但我有个例外:
org.codehaus.jackson。map。exx . unrecognizedpropertyexception:无法识别的字段“red”
可以有普通的getter/setter对。您只需要在@JsonProperty中指定访问模式
下面是单元测试:
public class JsonPropertyTest {
private static class TestJackson {
private String color;
@JsonProperty(value = "device_color", access = JsonProperty.Access.READ_ONLY)
public String getColor() {
return color;
};
@JsonProperty(value = "color", access = JsonProperty.Access.WRITE_ONLY)
public void setColor(String color) {
this.color = color;
}
}
@Test
public void shouldParseWithAccessModeSpecified() throws Exception {
String colorJson = "{\"color\":\"red\"}";
ObjectMapper mapper = new ObjectMapper();
TestJackson colotObject = mapper.readValue(colorJson, TestJackson.class);
String ser = mapper.writeValueAsString(colotObject);
System.out.println("Serialized colotObject: " + ser);
}
}
我得到的输出如下:
Serialized colotObject: {"device_color":"red"}
使用Jackson 2.9+引入的@JsonAlias进行注释，而不用在要用多个别名(json属性的不同名称)反序列化的项上提到@JsonProperty就可以了。
我使用com.fasterxml.jackson.annotation.JsonAlias与com.fasterxml.jackson.databind.ObjectMapper作为我的用例来实现包的一致性。
例如:
@Data
@Builder
public class Chair {
@JsonAlias({"woodenChair", "steelChair"})
private String entityType;
}
@Test
public void test1() {
String str1 = "{\"woodenChair\":\"chair made of wood\"}";
System.out.println( mapper.readValue(str1, Chair.class));
String str2 = "{\"steelChair\":\"chair made of steel\"}";
System.out.println( mapper.readValue(str2, Chair.class));
}
工作得很好。
可以有普通的getter/setter对。您只需要在@JsonProperty中指定访问模式
下面是单元测试:
public class JsonPropertyTest {
private static class TestJackson {
private String color;
@JsonProperty(value = "device_color", access = JsonProperty.Access.READ_ONLY)
public String getColor() {
return color;
};
@JsonProperty(value = "color", access = JsonProperty.Access.WRITE_ONLY)
public void setColor(String color) {
this.color = color;
}
}
@Test
public void shouldParseWithAccessModeSpecified() throws Exception {
String colorJson = "{\"color\":\"red\"}";
ObjectMapper mapper = new ObjectMapper();
TestJackson colotObject = mapper.readValue(colorJson, TestJackson.class);
String ser = mapper.writeValueAsString(colotObject);
System.out.println("Serialized colotObject: " + ser);
}
}
我得到的输出如下:
Serialized colotObject: {"device_color":"red"}
对于Kotlin的人:
data class TestClassDTO(
@JsonProperty("user_name")
val username: String
)
你将成功地从RestControllers中的POST有效载荷处理{"user_name": "John"}
但是当您需要用相同的@JsonProperty名称进行序列化时，您可以使用这种反射方法
fun Any.forceSerialize(separator: String, sorted: Boolean = false): String {
var fieldNameToAnnotatedNameMap = this.javaClass.declaredFields.map { it.name }.associateWith { fieldName ->
val jsonFieldName =
this::class.primaryConstructor?.parameters?.first { it.name == fieldName }?.annotations?.firstOrNull { it is JsonProperty }
val serializedName = if (jsonFieldName != null) (jsonFieldName as JsonProperty).value else fieldName
serializedName
}
if (sorted)
fieldNameToAnnotatedNameMap = fieldNameToAnnotatedNameMap.toList().sortedBy { (_, value) -> value}.toMap()
return fieldNameToAnnotatedNameMap.entries.joinToString(separator) { e ->
val field = this::class.memberProperties.first { it.name == e.key }
"${e.value}=${field.javaGetter?.invoke(this)}"
}
}
