{
    "code": "ascending-order-pq-4",
    "content": "Arrange the following decimal numbers in ascending order.\n4.3, 1.24, 2.4, 1.2",
    "ordering": 4,
    "options": {
        "answer_b": "4.3 < 2.4 < 1.24 < 1.2",
        "answer_a": "1.2 < 2.4 < 4.3 < 1.24",
        "answer_d": "1.2 < 1.24 < 2.4 < 4.3",
        "answer_c": "1.24 < 1.2 < 2.4 < 4.3"
    },
    "correct": "answer_d",
    "explaination": "Decimals are compared the same way as multi-digit numbers by keeping the number of digits the same with the help of trailing zeroes."
}

Currently I am having DTO like that:

private String code;
private String content;
private Integer ordering;
private HashMap<String,String> options;

private String correct;
private String explaination;

But it is throwing an exception as

Resolved [org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Cannot construct instance of java.util.HashMap (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('{:answer_a=>"1.2 < 2.4 < 4.3 < 1.24", :answer_b=>"4.3 < 2.4 < 1.24 < 1.2", :answer_c=>"1.24 < 1.2 < 2.4 < 4.3", :answer_d=>"1.2 < 1.24 < 2.4 < 4.3"}'); nested exception is com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot construct instance of java.util.HashMap (although at least one Creator exists): no String-argument constructor/factory method to deserialize from String value ('{:answer_a=>"1.2 < 2.4 < 4.3 < 1.24", :answer_b=>"4.3 < 2.4 < 1.24 < 1.2", :answer_c=>"1.24 < 1.2 < 2.4 < 4.3", :answer_d=>"1.2 < 1.24 < 2.4 < 4.3"}')

How should I make the DTO process the data coming?

CodePudding user response：

Your dto is missing constructor, getters and setters

CodePudding user response：

Assuming you are using Jackson to deserialize your JSON, you can fix this by including setters in your DTO:

public class YourDto {
    private String code;
    private String content;
    private Integer ordering;
    private HashMap<String,String> options;
    private String correct;
    private String explaination;

    public void setCode(String code) {
        this.code = code;
    }

    public void setContent(String content) {
        this.content = content;
    }

    public void setOrdering(Integer ordering) {
        this.ordering = ordering;
    }

    public void setOptions(HashMap<String, String> options) {
        this.options = options;
    }

    public void setCorrect(String correct) {
        this.correct = correct;
    }

    public void setExplaination(String explaination) {
        this.explaination = explaination;
    }
}

CodePudding user response：

Use like this.

public class ResponseDTO {
    
    @JsonProperty("code")
    private String code;
    
    @JsonProperty("content")
    private String content;

    @JsonProperty("ordering")
    private Integer ordering;

    @JsonProperty("options")
    private HashMap<String,String> options;

    @JsonProperty("correct")
    private String correct;

    @JsonProperty("explaination")
    private String explaination;
}