grails的clearErrors之后，注意事项

The Grails Framework - Groovy reference documentation

author：book = 1：多， book添加约束：title blank:false

def b = new org.bookstore.Book()b.validate()if (b.hasErrors()) {          println 'hasErrors'          b.clearErrors()          b.title = 'xx'          b.author = new org.bookstore.Author(name:'xxx')    //这一句不可以缺少          b.validate()          if (b.hasErrors()) {              b.clearErrors()              println 'still hasErrors'          }else {              println 'over'          }}