I am getting a map in my method from another server and I have some null values, I wanted to remove those ones, because I am struggling with those values in the following process:
My map looks something like:
I had done the next code, but without satisfactory results:
map.values().removeAll(Collections.singleton(null))
Any ideas?
Thanks
Edit
The Groovy way, is to filter the entries you want:
def map = [a:42, b:null]
def cleanMap = map.findAll{ it.value!=null }
println cleanMap
// => [a:42]
Previous answer:
Seems to work with Jdk8/Groovy 2.5, but not for OP
To remove all elements with a value with null, remove on the map directly:
def map = [a:42, b:null]
map.removeAll{ it.value == null }
println map
// => [a:42]
Related
I was doing a Groovy tutorial online there and after playing around with the code I observed some behaviour that I can't understand.
First I created a Map object like this:
def devMap = [:]
devMap = ['name':'Frankie', 'framework':'Grails', 'language':'Groovy']
devMap.put('lastName','Hollywood')
Then I called eachWithIndex to print out the values like so:
devMap.eachWithIndex { println "$it.key: $it.value"}
Which printed this to the console:
name: Frankie
framework: Grails
language: Groovy
lastName: Hollywood
But when I printed to the console from the eachWithIndex method like this using the arrow operator:
devMap.eachWithIndex { it, i -> println "$i: $it" }
The following got printed to the console:
0: name=Frankie
1: framework=Grails
2: language=Groovy
3: lastName=Hollywood
So what I can't understand is why the indexes got printed with the second statement and why there are = signs but no : signs between the key-value pairs?
Thanks.
When you use the no-arg version of eachWithIndex, it is the current entry in the Map. That means that it.key and it.value return what you expect.
When you use the two-arg version of eachWithIndex, again, it is the current entry in the Map and i is the current index. You're printing i, the index, and then since you are only printing it, you are getting the result of it.toString(), which formats the map entry as "${it.key}=${it.value}"
Your second example is equivalent to:
devMap.eachWithIndex { it, index -> println "$index: ${it.toString()}" }
where this shows that the toString() implementation uses the = syntax:
devMap.each { println it.toString() }
Note that this is closer to your goal (as I interpret it):
devMap.eachWithIndex { it, index -> println "$index: ${it.key}: ${it.value}" }
The list can be empty. I would like to do :
def value = "";
def list = getList()
if (!list.isEmpty()){
value = list.first().foo
}
for instance I have found this way :
assert ( [].find()?.foo?:"empty" ) == "empty"
assert ([[foo:"notEmpty1"], [foo:"notEmpty2"]].find()?.foo?:"empty") == "notEmpty1"
Is there a better way ?
Thanks! :)
EDIT:
I got great answer by using [0]
assert ( [][0]?.foo?:"empty" ) == "empty"
assert ([[foo:"notEmpty1"], [foo:"notEmpty2"]][0]?.foo?:"empty") == "notEmpty1"
If it is a List just try
if (!list?.isEmpty()){
list.get(0);
}
If the list element cannot be null you don't need the ?
If it is a Collection there are several forms to retrieve it. Take a look at this post
Java: Get first item from a collection
I got an answer from tweeter. The statements :
def value = "";
def list = getList()
if (!list.isEmpty()){
value = list.first().foo
}
Can be write :
def value = list[0]?.foo?:""
find may be use if the list can contain null values
Groovy code:
def line = "aa bb"
println line?.split("\\s+")?[1]
I want to use ? for an array to get an item. If the array is null, then return null, just like ?..
But the above code can't be compiled. How to fix it? Or is there any other simple alternative solution to this?
You can use getAt instead of [] (subscript operator)
def line = "aa bb"
println line?.split("\\s+")?.getAt(1)
http://groovyconsole.appspot.com/script/801001
It's the default behavior for List:
println (line?.split("\\s+")as List)[1]
I have two lists
def flagList = SystemFlag.list()
this contains the domain objects of one table
I have another list which I create using a query. One of the parameter in the object of this list is contained in the flagList. How can I find if an id of FlagList is present in the second list?
I can do it in plain java but I need to use Groovy for this.
If I understood you correctly you have this situation:
def listeOne = [1,2,3,4,5]
def listTwo = [2,5,1]
You want to see if '2' of 'listTwo' is in 'listOne'.
Find a specific value:
def found = 2 in listTwo //returns a boolean of the interger 2 is in listTwo
Search for common value of both lists:
def intersectionsList = listOne.intersect(listTwo) //gives you a list of value that are in BORTH list
You can also iterate like this:
listTwo.each { value ->
if(value in listOne) println value //or do something lese
}
Alternatively:
listTwo.each { value ->
listOne.find {value}?.toString() //you can perform an action on the object found in listOne. using '?.' will make sure no nullpointer will be thrown if there is no result.
}
I found it using
def it = itemtofindsomehow
list.findIndexof { iterator ->
iterator.domain.id == it.id
}
def map = [name:"Gromit", likes:"cheese", id:1234]
I would like to access map in such a way that I can get the key
something like the output should be
map.keys returns array of string. basically i just want to get the keys
output:
name
likes
id
try map.keySet()
and if you want an array:
map.keySet() as String[]; // thx #tim_yates
Or, more groovy-ish:
map.each{
key, value -> print key;
}
Warning: In Jenkins, the groovy-ish example is subtly broken, as it depends on an iterator. Iterators aren't safe in Jenkins Pipeline code unless wrapped in a #NonCPS function.
def map = [name:"Gromit", likes:"cheese", id:1234]
println map*.key
In groovy * is use for iterate all