Groovy merge two lists?
I have two lists:
listA:
[[Name: mr good, note: good,rating:9], [Name: mr bad, note: bad, rating:5]]
listB:
[[Name: mr good, note: good,score:77], [Name: mr bad, note: bad, score:12]]开发者_高级运维
I want to get this one
listC:
[[Name: mr good, note: good,, rating:9, score:77], [Name: mr bad, note: bad, rating:5,score:12]]
how could I do it ?
thanks.
collect all elements in listA, and find the elementA equivilient in listB. Remove it from listB, and return the combined element.
If we say your structure is the above, I would probably do:
def listC = listA.collect( { elementA ->
elementB = listB.find { it.Name == elementA.Name }
// Remove matched element from listB
listB.remove(elementB)
// if elementB == null, I use safe reference and elvis-operator
// This map is the next element in the collect
[
Name: it.Name,
note: "${it.note} ${elementB?.note :? ''}", // Perhaps combine the two notes?
rating: it.rating?:0 + elementB?.rating ?: 0, // Perhaps add the ratings?
score: it.score?:0 + elementB?.score ?: 0 // Perhaps add the scores?
] // Combine elementA + elementB anyway you like
}
// Take unmatched elements in listB and add them to listC
listC += listB
The subject of the question is somewhat general, so I'll post answer to a simplier question, if anyone got here looking for "How to merge two lists into a map in groovy?"
def keys = "key1\nkey2\nkey3"
def values = "value1,value2,value3"
keys = keys.split("\n")
values = values.split(",")
def map = [:]
keys.eachWithIndex() {param,i -> map[keys[i]] = values[i] }
print map
import groovy.util.logging.Slf4j
import org.testng.annotations.Test
@Test
@Slf4j
class ExploreMergeListsOfMaps{
final def listA = [[Name: 'mr good', note: 'good',rating:9], [Name: 'mr bad', note: 'bad',rating:5]]
final def listB = [[Name: 'mr good', note: 'good',score:77], [Name: 'mr bad', note: 'bad', score:12]]
void tryGroupBy() {
def listIn = listA + listB
def grouped = listIn.groupBy { item -> item.Name }
def answer = grouped.inject([], { candidate, item -> candidate += mergeMapkeys( item.value )})
log.debug(answer.dump())
}
private def mergeMapkeys( List maps ) {
def ret = maps.inject([:],{ mergedMap , map -> mergedMap << map })
ret
}
}
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