Question

我从angularjs传递json对象，该对象存储在数据

中

我想逐个注册/保存这些数据，但控制器不会进入foreach循环。

如果我的JSON对象密钥和DTO属性名称相同，我是否必须设置DTO的每个属性，如何简单地转换它？

@ResponseBody
    @RequestMapping(value = "/registerStudent.do", method = RequestMethod.POST)
    public boolean registerStudent(@RequestBody String data) {

        Gson googleJson = new Gson();

        ArrayList<StudentDTO> stdList = googleJson.fromJson(data, ArrayList.class);

        if (stdList != null) {

            for (StudentDTO stdObj : stdList) {

                registerService.register(stdObj);
            }

        }
        return registerService.isStudentExist(stdList);

    }

我的JSON对象是这样的：

[{fname=Karmesh, lname=Madhavi, gender=Male, dob=2016-11-07T18:30:00.000Z, email=abcd@gmail.com, contact=1234567890, yop=2020, degree=M.Sc, branch=CS, perc=78, state=Karnataka, city=Bangalore}]

我的StudentDTO是这样的：

@Entity
@Table(name = "student_table")
public class StudentDTO implements Serializable {

    @Id
    @GenericGenerator(name = "incre", strategy = "increment")
    @GeneratedValue(generator = "incre")
    @Column(name = "s_id")
    @NotNull
    private int sid;

    @Column(name = "s_fname")
    @NotNull
    @Size(min = 3, max = 20)
    private String fname;

    @Column(name = "s_lname")
    @NotNull
    private String lname;

    @Column(name = "s_gender")
    @NotNull
    private String gender;

    @Column(name = "s_dob")
    private Date dob;

    @Column(name = "s_email")
    @NotNull    
    private String email;

    @Column(name = "_scontact")
    @NotNull @Pattern(regexp="\\d{10}")
    private String contact;

    @Column(name = "s_yop")
    @NotNull @Min(4) @Max(4)
    private int yop;

    @Column(name = "s_degree")
    @NotNull
    private String degree;

    @Column(name = "s_branch")
    @NotNull
    private String branch;

    @Column(name = "s_perc")
    @NotNull @Digits(integer=2, fraction=2)
    private double perc;

    @Column(name = "s_state")
    @NotNull
    private String state;

    @Column(name = "s_city")
    @NotNull
    private String city;

    public StudentDTO() {
        System.out.println(this.getClass().getSimpleName() + "created..");
    }

    public String getFname() {
        return fname;
    }

    public void setFname(String fname) {
        this.fname = fname;
    }

    public String getLname() {
        return lname;
    }

    public void setLname(String lname) {
        this.lname = lname;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public int getSid() {
        return sid;
    }

    public void setSid(int sid) {
        this.sid = sid;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public Date getDob() {
        return dob;
    }

    public void setDob(Date dob) {
        this.dob = dob;
    }

    public int getYop() {
        return yop;
    }

    public void setYop(int yop) {
        this.yop = yop;
    }

    public String getDegree() {
        return degree;
    }

    public void setDegree(String degree) {
        this.degree = degree;
    }

    public String getBranch() {
        return branch;
    }

    public void setBranch(String branch) {
        this.branch = branch;
    }

    public double getPerc() {
        return perc;
    }

    public void setPerc(double perc) {
        this.perc = perc;
    }

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    @Override
    public String toString() {
        return "StudentDTO [sid=" + sid + ", fname=" + fname + ", lname=" + lname + ", gender=" + gender + ", dob="
                + dob + ", email=" + email + ", yop=" + yop + ", degree=" + degree + ", branch=" + branch + ", perc="
                + perc + ", state=" + state + ", city=" + city + "]";
    }

}

Answer 1

我认为它会抛出以下异常。

Exception in thread "main" java.lang.ClassCastException: com.google.gson.internal.LinkedTreeMap cannot be cast to com.example.model.StudentDTO

<强>解决方案： -

更改此声明： -

ArrayList<StudentDTO> stdList = gson.fromJson(data, ArrayList.class);

要： -

List<StudentDTO> stdList = gson.fromJson(data, new TypeToken<ArrayList<StudentDTO>>() {}.getType());

这应解决问题。它对我有用。

如何将列表中的每个对象转换为特定的DTO / POJO类？

1 个答案: