我刚刚根据新的(ish)java 8 时间包将我的许多日期转换为 LocalDateTime。在我开始尝试序列化和反序列化之前,我一直很喜欢这种转换。
我如何配置 Jackson 来支持它们?:
LocalDateTime --serialize--> UTC 时间戳 --deserialize--> LocalDateTime?
这里有很多关于转换为格式化字符串的资料,但我似乎找不到针对 utc 时间戳的现成解决方案。
最佳答案
您可以为 LocalDateTime
自定义序列化器和反序列化器,例如:
CustomLocalDateTimeSerializer
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.SerializerProvider;
import com.fasterxml.jackson.databind.ser.std.StdSerializer;
import java.io.IOException;
import java.time.LocalDateTime;
import java.time.ZoneId;
public class CustomLocalDateTimeSerializer extends StdSerializer<LocalDateTime> {
protected CustomLocalDateTimeSerializer(Class<LocalDateTime> t) {
super(t);
}
protected CustomLocalDateTimeSerializer() {
this(null);
}
@Override
public void serialize(LocalDateTime value, JsonGenerator gen, SerializerProvider sp)
throws IOException {
Long epoch = value.atZone(ZoneId.systemDefault()).toInstant().getEpochSecond();
gen.writeString(epoch.toString());
}
}
CustomLocalDateTimeDesSerializer:
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.databind.DeserializationContext;
import com.fasterxml.jackson.databind.deser.std.StdDeserializer;
import java.io.IOException;
import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;
class CustomLocalDateTimeDesSerializer extends StdDeserializer<LocalDateTime> {
protected CustomLocalDateTimeDesSerializer() {
this(null);
}
protected CustomLocalDateTimeDesSerializer(Class<LocalDateTime> t) {
super(t);
}
@Override
public LocalDateTime deserialize(JsonParser jsonparser, DeserializationContext context)
throws IOException {
Long timestamp = Long.parseLong(jsonparser.getText());
return LocalDateTime.ofInstant(Instant.ofEpochSecond(timestamp), ZoneId.systemDefault());
}
}
并使用它们:
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import java.time.LocalDateTime;
public class RestObject {
private LocalDateTime timestamp = LocalDateTime.now();
@JsonSerialize(using = CustomLocalDateTimeSerializer.class)
@JsonDeserialize(using = CustomLocalDateTimeDesSerializer.class)
public LocalDateTime getTimestamp() {
return timestamp;
}
public static void main(String[] args) throws Exception {
ObjectMapper objectMapper = new ObjectMapper();
// {"timestamp":"1549026058"}
System.out.println(objectMapper.writeValueAsString(new RestObject()));
}
}
关于java - 使用 Jackson 将 Java8 LocalDateTime 序列化为 UTC 时间戳,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/54479704/