AJAX POST JSON 到 Spring Controller 给出 JsonParseException

Question

Despite looking at all similar posts I'm unable to figure out my problem. I'm storing the response body JSON object of one AJAX call in a global variable and sending it back in another POST request to my Spring controller like so:

$(document).on("click", "#claimButton", function(){
        console.log(JSON.stringify(groupJSON));
        $.ajax({
            headers: {
                'Accept': 'application/json',
                'Content-Type': 'application/json'
            },
            type: "POST",
            url: "/Claim",
            data: {"group": JSON.stringify(groupJSON)},
            dataType: "json",
            success: function(result){

            }
        })
    });

I've also tried replacing JSON.stringify(groupJSON) with groupJSON but it made no difference.

My controller takes group in the request body:

@PostMapping(value = "/Claim", produces = MediaType.APPLICATION_JSON_VALUE, consumes = MediaType.APPLICATION_JSON_VALUE)
    public String groupClaim(@RequestBody Group group){
        return "Claim";
    }

But Spring gives the following error:

Resolved [org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Unrecognized token 'group': was expecting (JSON String, Number, Array, Object or token 'null', 'true' or 'false'); nested exception is com.fasterxml.jackson.core.JsonParseException: Unrecognized token 'group': was expecting (JSON String, Number, Array, Object or token 'null', 'true' or 'false')
 at [Source: (PushbackInputStream); line: 1, column: 7]]

Printing the JSON to console I get:

{"groupID":1,"groupName":"bobby","groupMembers":[{"password":"$2a$12$lRi5zjM1MgZq7lxs9cfp4O4JC1UIAE50WztJOpeX6Yu4F1epD5Qbm","email":"bob@","roles":[{"name":"Admin","id":3},{"name":"Student","id":1}],"userId":1,"username":"bob"}],"framework":{"frameworkID":45,"frameworkName":"test","frameworkFoci":[{"focusCategory":"","focusName":"Math","focusExplanation":"","focusId":1}],"groups":[{"groupID":3,"groupName":"ds","groupMembers":[{"password":"$2a$12$lRi5zjM1MgZq7lxs9cfp4O4JC1UIAE50WztJOpeX6Yu4F1epD5Qbm","email":"bob@","roles":[{"name":"Admin","id":3},{"name":"Student","id":1}],"userId":1,"username":"bob"}],"framework":45},1]}}

Which when passed to a validator came back as valid.

Group Entity:

@Table(name="FocusGroups")
@Entity
@JsonIdentityInfo(generator = ObjectIdGenerators.PropertyGenerator.class,
        property = "groupID")
public class Group {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long groupID;
    private String groupName;
    
    @ManyToMany
    @JoinTable(name = "GroupMembers",
            joinColumns = @JoinColumn(
                    name = "groupID"),
            inverseJoinColumns = @JoinColumn(
                    name = "userID"))
    private Set<User> groupMembers = new HashSet<>();

    @ManyToOne(fetch = FetchType.EAGER, optional = false)
    @JoinColumn(name="frameworkID", nullable = false)
    private Framework framework;

    protected Group(){}

    public Group(String groupName, Set<User> groupMembers) {
        this.groupName = groupName;
        //this.foci = foci;
        this.groupMembers = groupMembers;
    }

    public Long getGroupID() {
        return groupID;
    }

    public void setGroupID(Long groupID) {
        this.groupID = groupID;
    }

    public String getGroupName() {
        return groupName;
    }

    public void setGroupName(String groupName) {
        this.groupName = groupName;
    }

    public Set<User> getGroupMembers() {
        return groupMembers;
    }

    public void setGroupMembers(Set<User> groupMembers) {
        this.groupMembers = groupMembers;
    }

    public Framework getFramework() {
        return framework;
    }

    public void setFramework(Framework framework) {
        this.framework = framework;
    }
}

What is causing this error?

Answer 1

Changing data: {"group": JSON.stringify(groupJSON)} to data: JSON.stringify(groupJSON) did the trick.