Spring MVC: complex object as parameter

Question

I started learning spring boot and I ran into problems. I have the following code:

@RestController
public class UserController {

    @RequestMapping("/")
    public String getMessageInfo(Message message) {
        return "Id is " + message.getId() + ", message is " + message.getMessage() + ", parameter good is " + message.isGood();
    }
}

Post class:

public class Message {
    private String message;
    private int id;
    private boolean good;

    public Message() {}

    public Message(int id) {this.id = id;}

    public Message(String message) {this.message = message;}

    public Message(boolean good) {this.good = good;}

    public Message(String message, boolean good, int id) {
        this.message = message;
        this.good = good;
        this.id = id;
    }

    public String getMessage() {
        return message;
    }

    public int getId() {
        return id;
    }

    public boolean isGood() {
        return good;
    }
}

And when I try to do something like this:

RestTemplate request = new RestTemplate();
String info = request.getForObject("http://localhost:8080/?id=4", String.class);

value is idignored. The same problem occurs when I send a request using a boolean parameter good(e.g. localhost:8080/?good=true). It is called the default constructor instead of Message(boolean)/ Message(int). But when I do something like localhost:8080/?message=1234, it is not ignored. Could you explain to me what the problem is?

And one more question: is it possible to send an instance of a class Messagein a getMessageInfodifferent way than localhost:8080/?message=1234&good=true&id=145? If I have more than 3 parameters? For example, if a class Messagehas 100 parameters?

Answer 1

, .

@RequestMapping("/",method=RequestMethod.POST)
public String getMessageInfo(@RequestBody Message message) {
    return message;
} 

method POST, , POST, @RequestBody Message message parameter. Message object request, @requestBody, Bean injected spring .

,

    final String uri = "http://localhost:8080/";

    Message message = new Message(1, "Adam",true);

    RestTemplate restTemplate = new RestTemplate();
    Message result = restTemplate.postForObject( uri, message, Message.class);

Message object , Bad request.

Answer 2

, smth :

@ModelAttribute("message")
    public Message getMessage(String message, boolean good, int id){
    return new Message(message, good, id);
}

@RequestMapping("/")
public String getUserInfo(@ModelAttribute("message") Message message) {
    return "Id is " + message.getId() + ", message is " + message.getMessage() + ", parameter good is " + message.isGood();
}

.

Answer 3

You can use this,

    MultiValueMap<String, String> params = new LinkedMultiValueMap<String, String>();
    params.add("id", 1);
    params.add("good", true);
    params.add("message", 1234);
    HttpHeaders requestHeaders = new HttpHeaders();
    requestHeaders.setContentType(MediaType.MULTIPART_FORM_DATA);
    HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<MultiValueMap<String, String>>(params, requestHeaders);


    RestTemplate restTemplate = new RestTemplate();
    Message message= restTemplate.postForObject("http://localhost:8080/", requestEntity, Message.class);