Basic Result<T,E> implementation

src/main/java/com/utp/utils/Result.java

@@ -0,0 +1,52 @@
+package com.utp.utils;
+
+import java.util.Optional;
+import java.util.function.Function;
+
+public class Result<T, E> {
+
+    private Optional<T> value;
+    private Optional<E> error;
+
+    private Result(T value, E error) {
+        this.value = Optional.ofNullable(value);
+        this.error = Optional.ofNullable(error);
+    }
+
+    public static <U, E> Result<U, E> ok(U value) {
+        return new Result<>(value, null);
+    }
+
+    public static <U, E> Result<U, E> error(E error) {
+        return new Result<>(null, error);
+    }
+
+    public boolean isError() {
+        return error.isPresent();
+    }
+
+    public boolean isOk() {
+        return value.isPresent();
+    }
+
+    public T unwrapOk() throws RuntimeException {
+        if (this.isError())
+            throw new RuntimeException("Called unwrapOk on an error Result");
+        return value.get();
+    }
+
+    public E unwrapError() throws RuntimeException {
+        if (this.isOk())
+            throw new RuntimeException("Called unwrapError on an ok Result");
+        return error.get();
+    }
+
+    public <U> Result<U, E> flatMap(Function<T, Result<U,E>> mapper) {
+
+        if (this.isError()) {
+            return Result.error(error.get());
+        }
+
+        return mapper.apply(value.get());
+    }
+}