How to serialize Long epoch date format into date using JSONObject

I have json string payload having date in epoch (long) format.But I have to convert that into yyyyMMddHHmmss format.I'm using custom serializers where I can apply that on particular field.But the serialization is not able to apply on that field.

Test.java

 private static String json = "{
         
          "dcCountryCode": "US",
          "orderDate": 1517855400000
        }";



    @JsonSerialize(using = CustomLongSerializer.class)
    private static Long date;

    public static void main(String[] args) {

     
        JSONObject obj = new JSONObject(json);

        String country = obj.getString("dcCountryCode");

        date = obj.getLong("orderDate");

        
        System.out.println(country);
        
        System.out.println(date);

    }

CustomLongSerializer.java

    package com.company;
    
    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.text.SimpleDateFormat;
    
    
    // This is for Custom Date serializer
    public class CustomLongSerializer extends StdSerializer<Long> {
    
        protected CustomLongSerializer(Class<Long> t) {
            super(t);
        }
    
        protected CustomLongSerializer() {
            this(Long.class);
        }
    
        private static final long serialVersionUID = 1L;
    
        @Override
        public void serialize(Long value, JsonGenerator gen, SerializerProvider provider) throws IOException {
    
            SimpleDateFormat df = new SimpleDateFormat("yyyyMMddHHmmss");
            gen.writeString(df.format(value));
    
        }
    
    }



Expected Out put in yyyyMMddHHmmss format.

But still returning epoch date format.

Can anyone help me with this.


</details>


# 答案1
**得分**: 0

以下是您要翻译的内容：

可能通过禁用 `SerializationFeature.WRITE_DATES_AS_TIMESTAMPS` 并在映射器中设置日期格式化程序来以更简单的方式实现：

```java
public class TestDate {
    private String dcCountryCode;
    private Date date;
    // 获取器/设置器
}

// 测试类
String json = "{\"dcCountryCode\": \"US\",\"date\": 1517855400000}";

ObjectMapper mapper = new ObjectMapper()
                .disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
                .setDateFormat(new SimpleDateFormat("yyyyMMddHHmmss"));

TestDate test = mapper.readValue(json, TestDate.class);

System.out.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(test));

输出结果：

{
  "dcCountryCode" : "US",
  "date" : "20180205203000"
}

public class TestDate {
    private String dcCountryCode;
    private Date date;
// getters/setters
}

// test class
String json = "{\n" +
"          \"dcCountryCode\": \"US\",\n" +
"          \"date\": 1517855400000\n" +
"        }";

ObjectMapper mapper = new ObjectMapper()
                .disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
                .setDateFormat(new SimpleDateFormat("yyyyMMddHHmmss"));

TestDate test = mapper.readValue(json, TestDate.class);

System.out.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(test));

{
  "dcCountryCode" : "US",
  "date" : "20180205203000"
}