In this source code example, we show how to filter a map by its keys in Java 8 with an exmaple.
Java 8 Stream filter map by keys
The example filters domain names starting with s letter.:
import java.util.HashMap; import java.util.Map; public class JavaStreamFilterMapByKeys { public static void main(String[] args) { Map hmap = new HashMap<>(); hmap.put("de", "Germany"); hmap.put("in", "India"); hmap.put("sk", "Slovakia"); hmap.put("si", "Slovenia"); hmap.put("so", "Somalia"); hmap.put("us", "United States"); hmap.put("ru", "Russia"); hmap.entrySet().stream().filter(map -> map.getKey().startsWith("s")) .forEach(m -> System.out.println(m)); } }
Output:
si=Slovenia sk=Slovakia so=Somalia
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