Grails - 從請求參數返回選定的json元素

Question

在我的項目中，我試圖從請求的參數中返回選定的元素作爲JSON。

域類：

class Component{ 
    String name 
    String level 
    . 
    . 
    . 
} 

我有HTTP請求像

http://localhost:8080/myapp/component/showJson?name=name 

所以我應該只返回

{ 
    name:xyz 
} 

如果我的要求是一樣

http://localhost:8080/myapp/component/showJson?name=name&level=level 

然後我應該回到

{ 
    name:xyz 
    level:1 
} 

任何建議表示讚賞。

更新JSON（多級）

[ 
    {"name":"one","level":0," 
     componentTypes":[ 
       {"name":"one one","level":1, 
        "componentTypes":[ 
         {"name":"one one one","level":2,"componentTypes":[]} 
        ] 
       }, 
       {"name":"one two","level":1,"componentTypes":[]} 
     ] 
    }, 
    {"name":"two","level":0,"componentTypes"[]}, 
    {"name":"three","level":0,"componentTypes":[]} 
] 

class ComponentType { 
    String name 
    Integer level 
    static hasMany = [componentTypes:ComponentType] 
    ComponentType parent 
    static constraints = { 
     parent nullable:true 
    } 
    static mapWith = "mongo" 
} 

控制器動作

componentTypeList = ComponentType.createCriteria().list(){ 
      eq("level", 0) 
     } 

Answer 1

可以相交PARAMS與對象屬性映射映射並返回結果。我沒有嘗試過，但我想不出爲什麼它不起作用的原因。

def properties = component.properties; 
def result = properties.subMap(params.keySet()) 
render result as JSON 

更新：

class ComponentType { 

    . 
    . 
    . 



    def toJSON(def params) { 
     def properties = this.properties 
     def result = properties.subMap(params.keySet()) 
     if(this.componentTypes) { 
      result.componentTypes = componentTypes*.toJSON(params) 
     } 
     result 
    } 
} 


def componentTypeList = ComponentType.createCriteria().list(){ eq("level", 0) } 
render componentTypeList*.toJSON(params) as JSON