In this tutorial, we will see “How to Filter a Map by Key & Value using Java 8 Stream API?”
Filter a Map in Java 8 with examples...!!! Share on X
Example 1. Filter a Map by Key
/**
* Filter Map by Key
* @author Deepak Verma
*
*/
import java.util.Map;
import java.util.HashMap;
import java.util.stream.Collectors;
public class Filter_Map_By_Key_Java8 {
public static void main(String[] args) {
Map<Integer, String> studentsMap = new HashMap<Integer, String>();
studentsMap.put(43, "Yash");
studentsMap.put(98, "Sam");
studentsMap.put(61, "Gaurangee");
studentsMap.put(15, "Danny");
studentsMap.put(87, "Chris");
studentsMap.put(22, "Perry");
studentsMap.put(35, "Yashika");
studentsMap.put(58, "Lizzie");
Map<Integer, String> result = studentsMap.entrySet()
.stream()
.filter(x -> x.getKey().intValue() >= 40)
.collect(Collectors.toMap(x -> x.getKey(), x -> x.getValue()));
System.out.println("Students who scored more than the passing threshold of 40: \n\n" + result);
}
}
Output:
Students who scored more than the passing threshold of 40:
{98=Sam, 87=Chris, 58=Lizzie, 43=Yash, 61=Gaurangee}
Example 2. Filter a Map by Value
/**
* Filter Map by Value
* @author Deepak Verma
*
*/
import java.util.Map;
import java.util.HashMap;
import java.util.stream.Collectors;
public class Filter_Map_By_Value_Java8 {
public static void main(String[] args) {
Map<Integer, String> studentsMap = new HashMap<Integer, String>();
studentsMap.put(43, "Yash");
studentsMap.put(98, "Sam");
studentsMap.put(61, "Gaurangee");
studentsMap.put(15, "Danny");
studentsMap.put(87, "Chris");
studentsMap.put(22, "Perry");
studentsMap.put(35, "Yashika");
studentsMap.put(58, "Lizzie");
Map<Integer, String> result = studentsMap.entrySet()
.stream()
.filter(x -> (x.getValue().equals("Danny")))
.collect(Collectors.toMap(x -> x.getKey(), x -> x.getValue()));
System.out.println("Danny scored : " + result.keySet());
}
}
Output:
Danny scored : [15]
Filter a Map in Java 8 with examples...!!! Share on X
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