title: Can not instantiate value of type from JSON String; no single-String constructor/factory method
body: <p>I have following entities:</p>
  
  <pre><code>@Entity
  @Table(name="APLICACAO")
  public class Aplicacao implements Serializable, Entidade {
  
      private static final long serialVersionUID = 1L;
  
      @Id
      @GeneratedValue(strategy = GenerationType.IDENTITY)
      @Column(name="CD_APLICACAO")
      private Long codigo;
  
      @Column(name="NM_APLICACAO")
      @NotNull
      private String nome;
  
      @ManyToOne
      @JoinColumn(name="CD_GRUPO")
      private GrupoAplicacao grupoAplicacao;
  
      ....
  
  }
  </code></pre>
  
  <p>And also:</p>
  
  <pre><code>@Entity
  @Table(name = "GRUPO_APLICACAO")
  public class GrupoAplicacao implements Serializable, Entidade {
  
      private static final long serialVersionUID = 1L;
  
      @Id
      @GeneratedValue(strategy = GenerationType.IDENTITY)
      @Column(name = "CD_GRUPO")
      private Long codigo;
  
      @Column(name = "NM_GRUPO")
      @NotNull
      private String nome;
  
      @OneToMany(mappedBy = "grupoAplicacao",fetch=FetchType.EAGER)
      private List&lt;Aplicacao&gt; listaAplicacao;
  
      @OneToMany(mappedBy = "grupoAplicacao",fetch=FetchType.EAGER)
      private List&lt;GrupoAplicacaoUsuario&gt; listaGrupoAplicacaoUsuario;
  
      ....
  
  }
  </code></pre>
  
  <p>My HTML call controller "aplicacoesCreateController", like code bellow:</p>
  
  <pre><code>&lt;div class="col-xs-12" ng-controller="aplicacoesCreateController"&gt;
      &lt;form class="form-horizontal form-medium center" role="form" name="form" ng-submit="save()"&gt;
          &lt;div class="form-group"&gt;
              &lt;label for="nome" class="col-xs-4 control-label"&gt;Nome&lt;/label&gt;
              &lt;div class="col-xs-8"&gt;
                  &lt;input type="text" class="form-control input-sm" id="nome" placeholder="Nome" required ng-model="aplicacao.nome"&gt;
              &lt;/div&gt;
          &lt;/div&gt;
          &lt;div class="form-group"&gt;
              &lt;label for="nome" class="col-xs-4 control-label"&gt;Nome&lt;/label&gt;
              &lt;div class="col-xs-8"&gt;
                  &lt;select class="form-control" required ng-model="aplicacao.grupoAplicacao"&gt;
                          &lt;option ng-repeat="grupo in grupos" value="{{ grupo }}"&gt;
                              {{ grupo.nome }}
                          &lt;/option&gt;
                  &lt;/select&gt;
              &lt;/div&gt;
          &lt;/div&gt;
          &lt;div class="form-group"&gt;
              &lt;div class="col-xs-offset-4 col-xs-8"&gt;
              &lt;button type="submit" class="btn btn-lg btn-size-md"&gt;Salvar&lt;/button&gt;
              &lt;/div&gt;
          &lt;/div&gt;
      &lt;/form&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>And my Controller JavaScript:</p>
  
  <pre><code>app.controller('aplicacoesCreateController', ['$scope','aplicacoesService','$location','reloadService','gruposService',
  function ($scope,aplicacoesService,$location,reloadService,gruposService) {
      $scope.grupos = gruposService.list();
      $scope.save = function () {
          aplicacoesService.create($scope.aplicacao);
          reloadService.on('#/aplicacoes');
      };
  }]);
  </code></pre>
  
  <p>And Services JavaScript:</p>
  
  <pre><code>app.factory('gruposService', ['$resource', function ($resource) {
  
      return $resource('resources/grupo-aplicacao', {}, {
          'list': { method: 'GET', isArray: true }
      });
  
  }]);
  </code></pre>
  
  <p>And other service:</p>
  
  <pre><code>app.factory('aplicacoesService', ['$resource', function ($resource) {
  
      return $resource('resources/aplicacao', {}, {
          'list': { method: 'GET', isArray: true },
          'create': { method: 'POST' }
      });
  
  }]);
  </code></pre>
  
  <p>When insert aplicacao entity, is show me the following error:</p>
  
  <pre><code>Caused by: org.codehaus.jackson.map.JsonMappingException: Can not instantiate value of type [simple type, class br.com.techpeople.grape.entity.GrupoAplicacao] from JSON String; no single-String constructor/factory method (through reference chain: br.com.techpeople.grape.entity.Aplicacao["grupoAplicacao"])
  </code></pre>
  
  <p>Could you help me with this error?</p>