From aeb3f65a4cfef329d2920c5c6b5aedb89b7b134d Mon Sep 17 00:00:00 2001
From: Mark Paluch <mpaluch@pivotal.io>
Date: Wed, 28 Feb 2018 14:44:14 +0100
Subject: [PATCH] Annotate functional interfaces with FunctionalInterface.

Closes gh-204.
---
 .../vault/authentication/AppIdUserIdMechanism.java               | 1 +
 .../vault/authentication/ClientAuthentication.java               | 1 +
 .../org/springframework/vault/authentication/SessionManager.java | 1 +
 .../org/springframework/vault/client/VaultEndpointProvider.java  | 1 +
 .../org/springframework/vault/core/RestOperationsCallback.java   | 1 +
 5 files changed, 5 insertions(+)

diff --git a/spring-vault-core/src/main/java/org/springframework/vault/authentication/AppIdUserIdMechanism.java b/spring-vault-core/src/main/java/org/springframework/vault/authentication/AppIdUserIdMechanism.java
index 7e79a7fc..1e2b4e7a 100644
--- a/spring-vault-core/src/main/java/org/springframework/vault/authentication/AppIdUserIdMechanism.java
+++ b/spring-vault-core/src/main/java/org/springframework/vault/authentication/AppIdUserIdMechanism.java
@@ -23,6 +23,7 @@ package org.springframework.vault.authentication;
  * @author Mark Paluch
  * @see AppIdAuthentication
  */
+@FunctionalInterface
 public interface AppIdUserIdMechanism {
 
 	/**
diff --git a/spring-vault-core/src/main/java/org/springframework/vault/authentication/ClientAuthentication.java b/spring-vault-core/src/main/java/org/springframework/vault/authentication/ClientAuthentication.java
index 87ef5d91..1db439c1 100644
--- a/spring-vault-core/src/main/java/org/springframework/vault/authentication/ClientAuthentication.java
+++ b/spring-vault-core/src/main/java/org/springframework/vault/authentication/ClientAuthentication.java
@@ -25,6 +25,7 @@ import org.springframework.vault.support.VaultToken;
  *
  * @author Mark Paluch
  */
+@FunctionalInterface
 public interface ClientAuthentication {
 
 	/**
diff --git a/spring-vault-core/src/main/java/org/springframework/vault/authentication/SessionManager.java b/spring-vault-core/src/main/java/org/springframework/vault/authentication/SessionManager.java
index 91299ce8..0aee6148 100644
--- a/spring-vault-core/src/main/java/org/springframework/vault/authentication/SessionManager.java
+++ b/spring-vault-core/src/main/java/org/springframework/vault/authentication/SessionManager.java
@@ -29,6 +29,7 @@ import org.springframework.vault.support.VaultToken;
  * @see SimpleSessionManager
  * @see ClientAuthentication
  */
+@FunctionalInterface
 public interface SessionManager {
 
 	/**
diff --git a/spring-vault-core/src/main/java/org/springframework/vault/client/VaultEndpointProvider.java b/spring-vault-core/src/main/java/org/springframework/vault/client/VaultEndpointProvider.java
index 8d10622f..49480d1c 100644
--- a/spring-vault-core/src/main/java/org/springframework/vault/client/VaultEndpointProvider.java
+++ b/spring-vault-core/src/main/java/org/springframework/vault/client/VaultEndpointProvider.java
@@ -22,6 +22,7 @@ package org.springframework.vault.client;
  * @author Mark Paluch
  * @since 1.1
  */
+@FunctionalInterface
 public interface VaultEndpointProvider {
 
 	/**
diff --git a/spring-vault-core/src/main/java/org/springframework/vault/core/RestOperationsCallback.java b/spring-vault-core/src/main/java/org/springframework/vault/core/RestOperationsCallback.java
index 21fa93cc..f7be2de9 100644
--- a/spring-vault-core/src/main/java/org/springframework/vault/core/RestOperationsCallback.java
+++ b/spring-vault-core/src/main/java/org/springframework/vault/core/RestOperationsCallback.java
@@ -23,6 +23,7 @@ import org.springframework.web.client.RestOperations;
  *
  * @author Mark Paluch
  */
+@FunctionalInterface
 public interface RestOperationsCallback<T> {
 
 	/**