Merge pull request #6263 from cscib/master

BAEL-2534 - Determine if all elements are the same in a Java list
2019-02-14 20:05:34 +01:00
parent 69e29b364d 6faaedddb4
commit 6bdf463da9
2 changed files with 227 additions and 0 deletions
@@ -0,0 +1,55 @@
+package com.baeldung.allequalelements;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import org.apache.commons.collections4.IterableUtils;
+import com.google.common.base.Predicate;
+import com.google.common.collect.Iterables;
+
+public class VerifyAllEqualListElements {
+
+    public boolean verifyAllEqualUsingALoop(List<String> list) {
+        for (String s : list) {
+            if (!s.equals(list.get(0)))
+                return false;
+        }
+        return true;
+    }
+
+    public boolean verifyAllEqualUsingHashSet(List<String> list) {
+        return new HashSet<String>(list).size() <= 1;
+    }
+
+    public boolean verifyAllEqualUsingFrequency(List<String> list) {
+        return list.isEmpty() || Collections.frequency(list, list.get(0)) == list.size();
+    }
+
+    public boolean verifyAllEqualUsingStream(List<String> list) {
+        return list.stream()
+            .distinct()
+            .count() <= 1;
+    }
+
+    public boolean verifyAllEqualAnotherUsingStream(List<String> list) {
+        return list.isEmpty() || list.stream()
+            .allMatch(list.get(0)::equals);
+    }
+
+    public boolean verifyAllEqualUsingGuava(List<String> list) {
+        return Iterables.all(list, new Predicate<String>() {
+            public boolean apply(String s) {
+                return s.equals(list.get(0));
+            }
+        });
+    }
+
+    public boolean verifyAllEqualUsingApacheCommon(List<String> list) {
+        return IterableUtils.matchesAll(list, new org.apache.commons.collections4.Predicate<String>() {
+            public boolean evaluate(String s) {
+                return s.equals(list.get(0));
+            }
+        });
+    }
+
+}