Add Temporal annoation as Date skips Gson Serialization on Rest api Request

问题

In my java application i was using REST API that returned data in JSON format, and noticed that this particular API formatted it's dates in a peculiar way: "Nov 1, 2019" , But problem is that the actual date on the server is "2019-11-02".That means I am getiing date minimized to previous date.I have added gson serialization for both Date and Timestamp values using UTC timezone format, but what i noted is the Date values skip the serialization part on the code and only Timestamp values are using the serialization.I have used @Temporal(TemporalType.DATE) for date values that why it skips the date serialization.My server is on another country.Below is the complete json that i got after formatting.

jsonAccts [{"id":8,"userId":2,"departmentId":45,"effectiveFrom":"Jun 9, 2019","endsOn":"Nov 1, 2019","createdBy":2,"createdOn":"2019-11-02 05:34:11"}]

Below is the code that i used for gson formatting.

Gson gson;
GsonBuilder builder;
SimpleDateFormat dtf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.ENGLISH);
SimpleDateFormat dtfDate=new SimpleDateFormat("yyyy-MM-dd", Locale.ENGLISH);
String jsonAccts = null;
try{
    builder = new GsonBuilder();
    builder.registerTypeAdapter(Timestamp.class, new JsonSerializer<Timestamp>() {
        @Override
        public JsonElement serialize(Timestamp src, Type typeOfSrc, JsonSerializationContext context) {
            dtf.setTimeZone(TimeZone.getTimeZone("UTC"));
            String jsDate = dtf.format(src);
            return new JsonPrimitive(jsDate);
        }
    });
    builder.registerTypeAdapter(Date.class, new JsonSerializer<Date>() {
        @Override
        public JsonElement serialize(Date src, Type typeOfSrc, JsonSerializationContext context) {
            dtf.setTimeZone(TimeZone.getTimeZone("UTC"));
            String jsDate = dtf.format(src);
            return new JsonPrimitive(jsDate);
        }
    });
    gson = builder.create();
    List<ClassTeacher> allActPgmMap = new ArrayList<ClassTeacher>();
    allActPgmMap = springDao.getClassTeacherList(Integer.parseInt(deptId));
    Type listType = new TypeToken<List<ClassTeacher>>() {}.getType();
    jsonAccts = gson.toJson(allActPgmMap, listType);
}catch(Exception e){
    e.printStackTrace();
}
return jsonAccts;

Here the builder.registerTypeAdapter(Date.class, new JsonSerializer<Date>() {} is been not used for effectiveFrom and endsOn on api request. Below is the ClassTeacher class.

import javax.persistence.*;
    import java.io.Serializable;
    import java.sql.Timestamp;
    import java.util.Date;

    @Entity
    @Table(name = "class_teacher")
    public class ClassTeacher implements Serializable {

        @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        @Column(name = "id")
        private long id;

        @Column(name = "user_id")
        private long userId;

        @Column(name = "department_id")
        private long departmentId;

        @Column(name = "effective_from")
        @Temporal(TemporalType.DATE)     
        private Date effectiveFrom;

        @Column(name = "ends_on")
        @Temporal(TemporalType.DATE)     
        private Date endsOn;

        @Column(name="created_by")
        private long createdBy;

        @Column(name="created_on")
        private Timestamp createdOn;

        public ClassTeacher() {

        }

        public ClassTeacher(long id, long departmentId, long userId, Date effectiveFrom, Date endsOn, long createdBy, Timestamp createdOn) {
            this.id = id;
            this.departmentId = departmentId;
            this.userId = userId;
            this.effectiveFrom = effectiveFrom;
            this.endsOn = endsOn;
            this.createdBy = createdBy;
            this.createdOn = createdOn;
        }

        public long getId() {
            return id;
        }

        public void setId(long id) {
            this.id = id;
        }

        public long getUserId() {
            return userId;
        }

        public void setUserId(long userId) {
            this.userId = userId;
        }

        public long getDepartmentId() {
            return departmentId;
        }

        public void setDepartmentId(long departmentId) {
            this.departmentId = departmentId;
        }

        public Date getEffectiveFrom() {
            return effectiveFrom;
        }

        public void setEffectiveFrom(Date effectiveFrom) {
            this.effectiveFrom = effectiveFrom;
        }

        public Date getEndsOn() {
            return endsOn;
        }

        public void setEndsOn(Date endsOn) {
            this.endsOn = endsOn;
        }

        public long getCreatedBy() {
            return createdBy;
        }

        public void setCreatedBy(long createdBy) {
            this.createdBy = createdBy;
        }

        public Timestamp getCreatedOn() {
            return createdOn;
        }

        public void setCreatedOn(Timestamp createdOn) {
            this.createdOn = createdOn;
        }
    }

Here the createdOn is using the builder.registerTypeAdapter(Timestamp.class, new JsonSerializer<Timestamp>() {},but effectiveFrom and endsOn are not using the serializer.I have used 'com.google.code.gson:gson:2.8.1' here for gson.

来源：https://stackoverflow.com/questions/58688079/add-temporal-annoation-as-date-skips-gson-serialization-on-rest-api-request