2

我在地图中存储了一些 GString，并试图在运行时将它们评估为：

//this is in begginning of my class or controller or service and is a global variable
def placeholderStrings=["nameString":"My name is $name","professionString":"My profession is $profession"]

//this params map comes after arrival of request from client side and following code is inside the controller
params=["name":"name1","profession":"profession1"]
def paramsKeyMap=params.keySet()
paramsKeyMap.each{
    bindings."$it"=params[it]
    println it
}
println placeholderStrings.get("nameString") // this line gives error as groovy.lang.MissingPropertyException: No such property: name

上面的代码给出了错误，但下面的代码运行：

params=["name":"name1","profession":"profession1"]
def keyMap=params.keySet()
keyMap.each { 
    binding[it] =params[it] 
    println it // or even binding[it] = 'something' 
}
//Now I am declaring it locally pls note this
def placeholderStrings=["nameString":"My name is $name","professionString":"My profession is $profession"]
println placeholderStrings.get("nameString") // this line gives error as groovy.lang.MissingPropertyException: No such property: name

正如我们所看到的区别，在第一个脚本中，placeholderStrings 在绑定之前声明，而在第二个脚本中，它是在绑定之后声明的。我想做类似于第一种情况的事情，因为在我的应用程序中，我需要在运行时根据客户端请求评估占位符字符串。

  • 当请求到来时，我需要使用placeholderStrings.get(keyFromParams).
  • 用上面获得的字符串中的绑定替换占位符。

现在的问题是，当我调用 时placeholderStrings.get(keyFromParams)，它会尝试替换字符串中的占位符并引发异常。

为了解决这个问题，我尝试将 placeholderString 值存储为单引号字符串，例如：

def placeholderStrings=["nameString":'My name is $name',"professionString":'My profession is $profession']

但是现在我无法将上面映射中的值转换为 GString 以便可以替换占位符。所以有人可以建议可以做什么吗？

4

2 回答 2

4

Lazy GStrings（例如"My name is ${-> name}"）可能会解决问题，但将替换注入脚本绑定的整个方法对我来说就像是一个 hack（和潜在的安全漏洞）。使用模板引擎可能会更好。Groovy 附带SimpleTemplateEngineand GStringTemplateEngine，尽管有人告诉我使用它们很容易遇到内存泄漏问题（我不知道细节）。

于 2013-07-13T10:47:58.247 回答
2

使用扩展。

def exp = new Expando()

exp.nameString = {"My name is $name"}
exp.professionString = {"My profession is $profession"}

exp.name = "Rahul"
exp.profession = "SoftwareEngineer"

assert exp.nameString() == 'My name is Rahul'
assert exp.professionString() == 'My profession is SoftwareEngineer'

exp.name = "Sachin"
exp.profession = "Cricket"

assert exp.nameString() == 'My name is Sachin'
assert exp.professionString() == 'My profession is Cricket'

编辑
不使用 Expando

def params = [name: 'Rahul', age: 25, profession: 'developer']
def stringMap = params.collectEntries([:]){k, v ->
    def key = k + "String"
    [(key), "My $k is $v"]
}

assert stringMap instanceof java.util.LinkedHashMap
assert stringMap == [nameString:"My name is Rahul", ageString:"My age is 25", professionString:"My profession is developer"]
assert stringMap.nameString == "My name is Rahul"
于 2013-07-13T14:15:37.770 回答