POST parametros == null

Oi Marlei,

Posta aqui como está o seu código do Controller e da classe Form, e também como foi feita a requisição POST, para entendermos melhor o que pode estar acontecendo no seu caso.

package br.com.alura.forum.controller;

import java.util.List;

import javax.validation.Valid;

import java.net.URI;

import org.springframework.beans.factory.annotation.Autowired; import org.springframework.http.ResponseEntity; import org.springframework.web.bind.annotation.GetMapping; import org.springframework.web.bind.annotation.PostMapping; import org.springframework.web.bind.annotation.RequestBody; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.util.UriComponentsBuilder;

import br.com.alura.forum.controller.dto.TopicoDto; import br.com.alura.forum.controller.form.TopicoForm; import br.com.alura.forum.modelo.Topico; import br.com.alura.forum.repository.CursoRepository; import br.com.alura.forum.repository.TopicoRepository;

@RestController @RequestMapping("/topicos") public class TopicosController {

@Autowired
private TopicoRepository topicoRepository;
@Autowired
private CursoRepository cursoRepository;


@GetMapping
public List<TopicoDto> lista(String nomeCurso) {        
    if(nomeCurso == null) {
        List<Topico> topicos = topicoRepository.findAll();        
        return TopicoDto.converter(topicos);
    }else {
        List<Topico> topicos = topicoRepository.findByCursoNome(nomeCurso);        
        return TopicoDto.converter(topicos);
    }
}

@PostMapping
public ResponseEntity<TopicoDto> cadastrar(@RequestBody @Valid TopicoForm form, UriComponentsBuilder uriBuilder) {    
    Topico topico = form.converter(cursoRepository);
    topicoRepository.save(topico);    

    Uri uri = uriBuilder.path("/topicos/{id}").buildAndExpand(topico.getId()).toUri();
    return ResponseEntity.created(uri).body(new TopicoDto(topico));
}

}

package br.com.alura.forum.controller.form;

import javax.validation.constraints.NotEmpty; import javax.validation.constraints.NotNull;

import org.hibernate.validator.constraints.Length;

import br.com.alura.forum.modelo.Curso; import br.com.alura.forum.modelo.Topico; import br.com.alura.forum.repository.CursoRepository;

//vem do cliente public class TopicoForm {

@NotNull @NotEmpty @Length(min=2)
private String titulo;

@NotNull @NotEmpty @Length(min=2)
private String mensagem; 

//@NotNull @NotEmpty
private String nomeDoCurso; //não pode ter o objeto curso


public String getTitulo() {
    return titulo;
}
public String getMensagens() {
    return mensagem;
}
public String getNomeDoCurso() {
    return nomeDoCurso;
}
public void setTitulo(String titulo) {
    this.titulo = titulo;
}
public void setMensagens(String mensagens) {
    this.mensagem = mensagens;
}
public void setNomeDoCurso(String nomeDoCurso) {
    this.nomeDoCurso = nomeDoCurso;
}

public Topico converter(CursoRepository cursoRepository) {
    Curso curso = cursoRepository.findByNome(nomeDoCurso);
    return new Topico(titulo, mensagem, curso);
}

}

POST http://localhost:8080/topicos

body: { "titulo": "Dúvida método", "mensagem": "Tag HTML", "nomeDoCurso": "Sping Boot" }

mensagem:

{ "timestamp": "2020-04-20T13:41:37.875+0000", "status": 400, "error": "Bad Request", "errors": [ { "codes": [ "NotNull.topicoForm.mensagem", "NotNull.mensagem", "NotNull" ], "arguments": [ { "codes": [ "topicoForm.mensagem", "mensagem" ], "arguments": null, "defaultMessage": "mensagem", "code": "mensagem" } ], "defaultMessage": "não pode ser nulo", "objectName": "topicoForm", "field": "mensagem", "rejectedValue": null, "bindingFailure": false, "code": "NotNull" }, { "codes": [ "NotEmpty.topicoForm.mensagem", "NotEmpty.mensagem", "NotEmpty" ], "arguments": [ { "codes": [ "topicoForm.mensagem", "mensagem" ], "arguments": null, "defaultMessage": "mensagem", "code": "mensagem" } ], "defaultMessage": "não pode estar vazio", "objectName": "topicoForm", "field": "mensagem", "rejectedValue": null, "bindingFailure": false, "code": "NotEmpty" } ],

"message": "Validation failed for object='topicoForm'. Error count: 2",
"trace": "org.springframework.web.bind.MethodArgumentNotValidException: Validation failed for argument [0] in public org.springframework.http.ResponseEntity<br.com.alura.forum.controller.dto.TopicoDto> br.com.alura.forum.controller.TopicosController.cadastrar(br.com.alura.forum.controller.form.TopicoForm,org.springframework.web.util.UriComponentsBuilder) with 2 errors: [Field error in object 'topicoForm' on field 'mensagem': rejected value [null]; codes [NotNull.topicoForm.mensagem,NotNull.mensagem,NotNull]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [topicoForm.mensagem,mensagem]; arguments []; default message [mensagem]]; default message [não pode ser nulo]] [Field error in object 'topicoForm' on field 'mensagem': rejected value [null]; codes [NotEmpty.topicoForm.mensagem,NotEmpty.mensagem,NotEmpty]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [topicoForm.mensagem,mensagem]; arguments []; default message [mensagem]]; default message [não pode estar vazio]] \r\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.resolveArgument(RequestResponseBodyMethodProcessor.java:139)\r\n\tat org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:127)\r\n\tat org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:167)\r\n\tat org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:134)\r\n\tat org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105)\r\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:893)\r\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:798)\r\n\tat org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)\r\n\tat org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)\r\n\tat org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)\r\n\tat org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)\r\n\tat org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)\r\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:660)\r\n\tat org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)\r\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:741)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\r\n\tat org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDo

Oi Marlei,

Vi que na sua classe TopicoForm o atributo se chama mensagem mas o método setter está como setMensagens, por isso o Spring gera erro de validação.

Altere para:

public void setMensagem(String mensagem) {
    this.mensagem = mensagem;
}

Oi Rodrigo, agora deu outra msg:

{ "timestamp": "2020-04-20T14:38:35.894+0000", "status": 500, "error": "Internal Server Error", "message": "Unresolved compilation problem: \n\tUri cannot be resolved to a type\n", "trace": "java.lang.Error: Unresolved compilation problem: \n\tUri cannot be resolved to a type\n\r\n\tat br.com.alura.forum.controller.TopicosController.cadastrar(TopicosController.java:51)\r\n\tat sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)\r\n\tat sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)\r\n\tat sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)\r\n\tat java.lang.reflect.Method.invoke(Unknown Source)\r\n\tat org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190)\r\n\tat org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138)\r\n\tat org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105)\r\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:893)\r\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:798)\r\n\tat org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)\r\n\tat org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040)\r\n\tat org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943)\r\n\tat org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006)\r\n\tat org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:909)\r\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:660)\r\n\tat org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883)\r\n\tat javax.servlet.http.HttpServlet.service(HttpServlet.java:741)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\r\n\tat org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\r\n\tat org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)\r\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\r\n\tat

org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\r\n\tat org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)\r\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\r\n\tat org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:94)\r\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\r\n\tat org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)\r\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)\r\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)\r\n\tat org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202)\r\n\tat org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)\r\n\tat org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541)\r\n\tat org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)\r\n\tat org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)\r\n\tat org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)\r\n\tat org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)\r\n\tat org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367)\r\n\tat org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)\r\n\tat org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:868)\r\n\tat org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1639)\r\n\tat org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)\r\n\tat java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)\r\n\tat java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)\r\n\tat org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)\r\n\tat java.lang.Thread.run(Unknown Source)\r\n", "path": "/topicos" }

Agora está com algum erro de compilação na classe TopicosController.

Parece que está faltando importar alguma classe no controller.

  Uri uri = uriBuilder.path("/topicos/{id}").buildAndExpand(topico.getId()).toUri();
return ResponseEntity.created(uri).body(new TopicoDto(topico));

a Uri tinha que ser assim URI, e eu tinha colocado Uri .

Obrigada pela ajuda!