如何使用Postman将数据传递给以下rest api类？

Question

基本上我不明白如何使用Postman发送数据rest-api类？ 当我使用Postman运行rest-api来保存记录时，它给出了我不支持应用程序json格式的错误..

我有以下课程来代表多对多关系

package com.ps.usercourse;

import java.io.Serializable;
import java.util.Objects;

import javax.persistence.EmbeddedId;
import javax.persistence.Entity;
import javax.persistence.ManyToOne;
import javax.persistence.MapsId;

import com.fasterxml.jackson.annotation.JsonBackReference;
import com.ps.course.Course;
import com.ps.user.User;

@Entity
public class UserCourse implements Serializable
{
    private static final long serialVersionUID = 46419863112677606L;

    @EmbeddedId
    private UserCourseId id;

    @ManyToOne
    @MapsId("emailId")
    @JsonBackReference
    User user;

    @ManyToOne
    @MapsId("courseId")
    @JsonBackReference
    Course course;

    Boolean isActive = true;

    public UserCourse() {
    }

    public UserCourse(User user, Course course, Boolean isActive) {
        this.user = user;
        this.course = course;
        this.isActive = isActive;
    }

    public UserCourse(UserCourseId id, User user, Course course, Boolean isActive) {
        this.id = id;
        this.user = user;
        this.course = course;
        this.isActive = isActive;
    }

    public UserCourseId getId() {
        return id;
    }

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

    public User getUser() {
        return user;
    }

    public void setUser(User user) {
        this.user = user;
    }

    public Course getCourse() {
        return course;
    }

    public void setCourse(Course course) {
        this.course = course;
    }

    public Boolean getIsActive() {
        return isActive;
    }

    public void setIsActive(Boolean isActive) {
        this.isActive = isActive;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;

        if (o == null || getClass() != o.getClass()) 
            return false;

        UserCourse that = (UserCourse) o;
        return Objects.equals(user, that.user) && 
               Objects.equals(course, that.course);
    }

    @Override
    public int hashCode() {
        return Objects.hash(user, course);
    }
}

这是我试图通过Postman打电话的休息api

@RequestMapping(value="/UserCourse",method=RequestMethod.POST)
@ResponseBody
public UserCourse addUser(@RequestBody UserCourse userCourse, HttpServletRequest req, HttpServletResponse res)
    {
        return userCourseService.save(userCourse);
    }