How to format the json output generated from rest api

I am working on spring boot, and it is a rest application. Whenever I call "localhost:8080/projects", I get an json data in the given below form.

{
uid: "166"
    code: "99991"
        name: "iPOC AG Mednet - BIOC"
            protocol: "iPOC AG Mednet - BIOC"
                client: "BioClinica"
                    description: "AG Mednet - BIOC PoC "
                        platform: "BioPACS"
                            subjectConfiguration: {
    displayInitials: true
    displayDOB: true
    displayGender: true
}
uploadConfiguration: {
    hasAttachments: true
    hasNonDicom: false
    autoInserted: true
}}

But I need it in the below given format:

{
"_embedded" : {
"projects" : [ {
    "uid" : "1",
    "code" : "123",
    "name" : "Project 1",
    "protocol" : "Protocol 1",
    "client" : "Client",
    "description" : "",
    "platform": "BioPACS",
    "subjectConfiguration" : {
    "displayInitials" : true,
    "displayDOB" : true,
    "displayGender" : true
},
"uploadConfiguration" : {
    hasAttachments: true,
    hasNonDicom: true,
    isAutoInserted: false,
},
"_links" : {
    "self" : {
    "href" : "http://localhost:8080/projects/123"
}
}
}]}}

And my "project" Class is as given below.

public class Project {

private String uid;
private String code;
private String name;
private String protocol;
private String client;
private String description;
private String platform;
private SubjectConfiguration subjectConfiguration;
private UploadConfiguration uploadConfiguration;

public String getUid() {
    return uid;
}

public void setUid(String uid) {
    this.uid = uid;
}

public String getCode() {
    return code;
}

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

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public String getProtocol() {
    return protocol;
}

public void setProtocol(String protocol) {
    this.protocol = protocol;
}

public String getClient() {
    return client;
}

public void setClient(String client) {
    this.client = client;
}

public String getDescription() {
    return description;
}

public void setDescription(String description) {
    this.description = description;
}

public String getPlatform() {
    return platform;
}

public void setPlatform(String platform) {
    this.platform = platform;
}

public SubjectConfiguration getSubjectConfiguration() {
    return subjectConfiguration;
}

public void setSubjectConfiguration(
        SubjectConfiguration subjectConfiguration) {
    this.subjectConfiguration = subjectConfiguration;
}

public UploadConfiguration getUploadConfiguration() {
    return uploadConfiguration;
}

public void setUploadConfiguration(UploadConfiguration uploadConfiguration) {
    this.uploadConfiguration = uploadConfiguration;
}

@Override
public String toString() {
    return "'uid':'" + uid + "', " + "'code':'" + code + "', "
            + "'name':'" + name + "', " + "'protocol':'" + protocol + "', "
            + "'client':'" + "', " + "'description':'" + description + "', "
            + "'platform':'" + platform + "', " + "'subjectConfiguration':'"
            + subjectConfiguration + "', " + "'uploadConfiguration':'"
            + uploadConfiguration + "'" ;
}}

And the method that returns the List is given below:

@RequestMapping(value = "/projects", method = RequestMethod.GET, produces = "application/json")
public @ResponseBody List<Project> getProject() {
    GetAuthorizedWebSendTransferProjects request = new GetAuthorizedWebSendTransferProjects();
    GetAuthorizedWebSendTransferProjectsResponse response = gw.getResponse(request);
    JAXBElement<ArrayOfProjectContainer> arr = response.getGetAuthorizedWebSendTransferProjectsResult();
    ArrayOfProjectContainer arr1 = arr.getValue();
    List<ProjectContainer> arr2 = arr1.getProjectContainer();
    List<Project> projects = getPopulatedProjectList(arr2);
    return projects;
}

Do I need to add any library to achieve this or should I modify my toString() method of Project class. Now the response header has "Content-Type: application/json" but the headers that I require is "Content-Type: application/hal+json".Can anybody help me out to resolve this issue. Thank you in Advance.