BAEL-2018 (#4753)

* BAEL-2018 * Update Animal.java * rename
2018-07-20 00:07:00 +05:00
parent a5b49fb919
commit 770e8b0219
3 changed files with 152 additions and 0 deletions
@@ -0,0 +1,27 @@
+package com.baeldung.convertlisttomap;
+
+public class Animal {
+    private int id;
+    private String name;
+
+    public Animal(int id, String name) {
+        this.id = id;
+        this.setName(name);
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+}
@@ -0,0 +1,52 @@
+package com.baeldung.convertlisttomap;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+import org.apache.commons.collections4.IterableUtils;
+import org.apache.commons.collections4.MapUtils;
+import com.google.common.collect.Maps;
+
+public class ConvertListToMapService {
+
+    public Map<Integer, Animal> convertListBeforeJava8(List<Animal> list) {
+        Map<Integer, Animal> map = new HashMap<Integer, Animal>();
+        for (Animal animal : list) {
+            map.put(animal.getId(), animal);
+        }
+        return map;
+    }
+
+    public Map<Integer, Animal> convertListAfterJava8(List<Animal> list) {
+        Map<Integer, Animal> map = list.stream().collect(Collectors.toMap(Animal::getId, animal -> animal));
+        return map;
+    }
+
+    public Map<Integer, Animal> convertListWithGuava(List<Animal> list) {
+
+        Map<Integer, Animal> map = Maps.uniqueIndex(list, Animal::getId);
+        return map;
+    }
+
+    public Map<Integer, Animal> convertListWithApacheCommons1(List<Animal> list) {
+
+        Map<Integer, Animal> map = new HashMap<Integer, Animal>();
+
+        IterableUtils.forEach(list, animal -> {
+            map.put(animal.getId(), animal);
+        });
+
+        return map;
+    }
+
+    public Map<Integer, Animal> convertListWithApacheCommons2(List<Animal> list) {
+
+        Map<Integer, Animal> map = new HashMap<Integer, Animal>();
+
+        MapUtils.populateMap(map, list, Animal::getId);
+
+        return map;
+    }
+}