给定这些域类:

class Person { 
    Long id 
    String name 
 
    static hasMany = [aliases: PersonAlias] 
} 
 
class PersonAlias { 
    Person person 
    Long id 
    String name 
} 

Person p = Person.get(20005353); 
def json = p as JSON 
def str = json as String 
def map = JSON.parse(str) 
p.properties = map 
p.save(flush:true) 

{ 
  "id": 20005353, 
  "name": "John Smith", 
  "class": "Person", 
  "aliases": 
  [ 
    { 
      "class": "PersonAlias", 
      "id": 99, 
      "name": "J. Smith" 
    } 
  ] 
} 

grails.validation.ValidationErrors: 1 errors Field error in object 'heavymeta.Person' on field 'aliases': rejected value [[]]; codes [typeMismatch.heavymeta.Person.aliases,typeMismatch.aliases,typeMismatch.java.util.Set,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [heavymeta.Person.aliases,aliases]; arguments []; default message [aliases]]; default message [Failed to convert property value of type 'org.codehaus.groovy.grails.web.json.JSONArray' to required type 'java.util.Set' for property 'aliases'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.util.LinkedHashMap] to required type [heavymeta.PersonAlias] for property 'aliases[0]': no matching editors or conversion strategy found]

请您参考如下方法:

我可以给您一些建议(=。在params操作中以 Debug模式检查update(如果尚未生成在控制台generate-all Person中运行的域类的 View 和 Controller )。看一看params.aliases，您会在列表中找到它ID。尝试相同的方法。