add java examples

java/functionnal/TriFunction.java

@@ -0,0 +1,20 @@
+package patterns.functionnal;
+
+import java.util.Objects;
+import java.util.function.Function;
+/**
+ * 
+ * @author pouyllau
+ *
+ */
+@FunctionalInterface
+public interface TriFunction<A,B,C,R> {
+
+    R apply(A a, B b, C c);
+
+    default <V> TriFunction<A, B, C, V> andThen(
+                                Function<? super R, ? extends V> after) {
+        Objects.requireNonNull(after);
+        return (A a, B b, C c) -> after.apply(apply(a, b, c));
+    }
+}