[LANG-1568]

org.apache.commons.lang3.function.FailableConsumer.andThen(FailableConsumer<?
super T, E>)

2 files changed, 36 insertions, 4 deletions

diff --git a/src/main/java/org/apache/commons/lang3/function/FailableBiFunction.java b/src/main/java/org/apache/commons/lang3/function/FailableBiFunction.java
index be0e4704b..3173c73b7 100644
--- a/src/main/java/org/apache/commons/lang3/function/FailableBiFunction.java
+++ b/src/main/java/org/apache/commons/lang3/function/FailableBiFunction.java
@@ -57,7 +57,7 @@ public interface FailableBiFunction<T, U, R, E extends Throwable> {
      * @param after the operation to perform after this one.
      * @return a composed {@code FailableBiFunction} that like {@link BiFunction#andThen(Function)}.
      * @throws E Thrown when a consumer fails.
-     * @throws NullPointerException if after is null.
+     * @throws NullPointerException if {@code after} is null.
      */
     default <V> FailableBiFunction<T, U, V, E> andThen(final FailableFunction<? super R, ? extends V, E> after) throws E {
         Objects.requireNonNull(after);
diff --git a/src/main/java/org/apache/commons/lang3/function/FailableConsumer.java b/src/main/java/org/apache/commons/lang3/function/FailableConsumer.java
index acb73cc51..c2f2de8a9 100644
--- a/src/main/java/org/apache/commons/lang3/function/FailableConsumer.java
+++ b/src/main/java/org/apache/commons/lang3/function/FailableConsumer.java
@@ -17,17 +17,33 @@
 
 package org.apache.commons.lang3.function;
 
+import java.util.Objects;
 import java.util.function.Consumer;
 
 /**
  * A functional interface like {@link Consumer} that declares a {@code Throwable}.
  *
- * @param <O> Consumed type 1.
+ * @param <T> Consumed type 1.
  * @param <E> Thrown exception.
  * @since 3.11
  */
 @FunctionalInterface
-public interface FailableConsumer<O, E extends Throwable> {
+public interface FailableConsumer<T, E extends Throwable> {
+
+    /** NOP singleton */
+    @SuppressWarnings("rawtypes")
+    final FailableConsumer NOP = t -> {/* NOP */};
+
+    /**
+     * Returns The NOP singleton.
+     *
+     * @param <T> Consumed type 1.
+     * @param <E> Thrown exception.
+     * @return The NOP singleton.
+     */
+    static <T, E extends Throwable> FailableConsumer<T, E> nop() {
+        return NOP;
+    }
 
     /**
      * Accepts the consumer.
@@ -35,5 +51,21 @@ public interface FailableConsumer<O, E extends Throwable> {
      * @param object the parameter for the consumable to accept
      * @throws E Thrown when the consumer fails.
      */
-    void accept(O object) throws E;
+    void accept(T object) throws E;
+
+    /**
+     * Returns a composed {@code Consumer} like {@link Consumer#andThen(Consumer)}.
+     *
+     * @param after the operation to perform after this operation
+     * @return a composed {@code Consumer} like {@link Consumer#andThen(Consumer)}.
+     * @throws E Thrown when a consumer fails.
+     * @throws NullPointerException if {@code after} is null
+     */
+    default FailableConsumer<T, E> andThen(final FailableConsumer<? super T, E> after) throws E {
+        Objects.requireNonNull(after);
+        return (final T t) -> {
+            accept(t);
+            after.accept(t);
+        };
+    }
 }