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我嘗試了json視圖，而不是在使用@Resource的域類的頂部，而是通過創建RestfulController並嘗試使用json視圖呈現該視圖。我在build config中添加了所有相關的依賴關係。當試圖在rest上使用JSON視圖時得到null屬性Controller只是從RestfulController中延伸
我有一個域Post類這樣的（這我不想直接暴露）
class Post implements Serializable {
Map comments
User user
Venue venue
String description
Rating rating //should this be an enum?
LocalDateTime dateCreated
LocalDateTime lastUpdated
static belongsTo = [user:User]
static hasOne = [rating:Rating]
static constraints = {
venue nullable:true
comments nullable:true
description nullable:true
rating nullable:true, lazy:false
}
static mapping = {
//set the sort order for Posts - default using newest post first
sort dateCreated :"desc"
}
}
，所以我再創建一個「默認restfulContoller這樣
class PostRestController extends RestfulController {
static responseFormats = ["json", "xml"]
//constructor - tells rest controller which domain class to scaffold
PostRestController() {
super (Post)
}
}
我是這裏不覆蓋任何默認的腳手架方法。
當我使用一個休息客戶端訪問默認（我已經映射/api/posts (resources: postRest UrlMappings）。當我和我的REST客戶端訪問URL我得到了郵政的完全轉儲（包括註釋字段堅持地圖） - 這個看起來像這樣在我休息的客戶 - 一切ok
[
{
"id": 1,
"comments": {
"view": "lovely"
},
"dateCreated": {
"class": "java.time.LocalDateTime",
"dayOfMonth": 7,
"dayOfWeek": {
"enumType": "java.time.DayOfWeek",
"name": "TUESDAY"
},
"dayOfYear": 66,
"hour": 19,
"minute": 15,
"month": {
"enumType": "java.time.Month",
"name": "MARCH"
},
"monthValue": 3,
"nano": 263000000,
"second": 10,
"year": 2017,
"chronology": {
"calendarType": "iso8601",
"class": "java.time.chrono.IsoChronology",
"id": "ISO"
}
},
"description": null,
"lastUpdated": {
"class": "java.time.LocalDateTime",
"dayOfMonth": 7,
"dayOfWeek": {
"enumType": "java.time.DayOfWeek",
"name": "TUESDAY"
},
"dayOfYear": 66,
"hour": 19,
"minute": 15,
"month": {
"enumType": "java.time.Month",
"name": "MARCH"
},
"monthValue": 3,
"nano": 263000000,
"second": 10,
"year": 2017,
"chronology": {
"calendarType": "iso8601",
"class": "java.time.chrono.IsoChronology",
"id": "ISO"
}
},
"rating": null,
"user": {
"id": 1
},
"venue": null
}
],
然後我試圖添加在grails-app/views/postRest夾在此之上JSON意見
我不喜歡這個
model {
Post post
}
json {
comments post.comments
description post.description
//rating post.rating
userWhoPosted "${post?.user}"
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MMM-dd")
def when = post.dateCreated.format(formatter)
created when
}
一個非常簡單的模板_post.gson我再補充一個`index.gson」呈現模板
model {
List<Post> postList
}
//call the template to iterate over the postList to produce the output
json g.render(postList)
這使服務器出現這種stracktrace和500錯誤到其他客戶端。如果我註釋掉與用戶有關的行in_post.gson，它一切正常。離開它，它失敗
Caused by: grails.views.ViewRenderException: Error rendering view: null
at grails.views.AbstractWritableScript.writeTo(AbstractWritableScript.groovy:43)
at grails.views.mvc.GenericGroovyTemplateView.renderMergedOutputModel(GenericGroovyTemplateView.groovy:73)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
at grails.views.mvc.renderer.DefaultViewRenderer.render(DefaultViewRenderer.groovy:111)
at grails.artefact.controller.RestResponder$Trait$Helper.internalRespond(RestResponder.groovy:188)
at grails.artefact.controller.RestResponder$Trait$Helper.respond(RestResponder.groovy:62)
at grails.rest.RestfulController.index(RestfulController.groovy:64)
at grails.transaction.GrailsTransactionTemplate$2.doInTransaction(GrailsTransactionTemplate.groovy:96)
at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:133)
at grails.transaction.GrailsTransactionTemplate.execute(GrailsTransactionTemplate.groovy:93)
... 4
如果我註釋出post.user（和評級參考）它工作正常。但是當我嘗試併發布post.user時，它與上述失敗。有大約確保文檔您查詢拉帶裁判記一個fetch連接 - 所以我試圖提供一個覆蓋，以確保我返回的抓取連接 - 我得到的是空返回給客戶端
class PostRestController extends RestfulController {
static responseFormats = ["json", "xml"]
//constructor - tells rest controller which domain class to scaffold
PostRestController() {
super (Post)
}
def index() {
Collection<Post> res = Post.list([fetch:[user:"join",rating:"join"]])
res
}
}
爲什麼當我這樣做沒有JSON視圖它工作正常，當我使用JSON視圖我不能得到輸出包括引用。我檢查到列表請求，並在調試成功返回列表中 - 但在渲染
打破，如果我能得到這個工作中，Grails JSON意見3.2.6看起來相當不錯
任何人有任何想法，爲什麼這會打破？