Groovy-将地图列表合并到一个地图中

Question

I have a list of maps which I am trying to combine into a single map. I've tried using map.collectEntries() to do so, but the map that was created contained only the last map from the list. My input list is following:

def people = [[name:'John', age:35], [name:'Jim', age:54]]

I expect to calculate a map like:

def people = ['John':35, 'Jim':54]

Answer 1

You have to collect entries from the map with a closure that access name and age

def people = [[name:'John', age:35], [name:'Jim', age:54], [name:'Smith', age:'53']]

def nameAgeMap=people.collectEntries() {
    [it.name, it.age]
}

println(nameAgeMap)

Answer 2

For simplicity:

Map<String, String> result = new HashMap<String, String>();
for (Map<String, String> singleMap : people) {
  result.putAll(singleMap);
}

Stream API:

You can do the same using the stream API, which might look for many developers overcomplicated.