DataLoader as an interface - 3.x branch

README.md

@@ -402,7 +402,9 @@ then you will not want to cache data meant for user A to then later give it user
 The scope of your `DataLoader` instances is important.  You might want to create them per web request to ensure data is only cached within that
 web request and no more.
 
-If your data can be shared across web requests then you might want to scope your data loaders so they survive longer than the web request say.
+If your data can be shared across web requests then use a custom cache to keep values in a common place.  You should however aim
+to keep the data loader instances per web request because they are stateful components that contain promises (with context)
+that are likely share the same affinity as the web request.
 
 ## Custom caches
 
@@ -461,7 +463,7 @@ repositories {
 }
 
 dependencies {
-    compile 'com.graphql-java:java-dataloader: 2.2.3'
+    compile 'com.graphql-java:java-dataloader: 3.0.0'
 }
 ```
 

src/main/java/org/dataloader/BatchLoader.java

@@ -16,6 +16,8 @@
 
 package org.dataloader;
 
+import org.dataloader.annotations.PublicSpi;
+
 import java.util.List;
 import java.util.concurrent.CompletionStage;
 

src/main/java/org/dataloader/BatchLoaderContextProvider.java

@@ -1,5 +1,7 @@
 package org.dataloader;
 
+import org.dataloader.annotations.PublicSpi;
+
 /**
  * A BatchLoaderContextProvider is used by the {@link org.dataloader.DataLoader} code to
  * provide overall calling context to the {@link org.dataloader.BatchLoader} call.  A common use

src/main/java/org/dataloader/BatchLoaderEnvironment.java

@@ -1,12 +1,15 @@
 package org.dataloader;
 
+import org.dataloader.annotations.PublicApi;
+
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
 import static java.util.Objects.nonNull;
+import static java.util.Objects.requireNonNull;
 
 /**
  * This object is passed to a batch loader as calling context.  It could contain security credentials
@@ -78,8 +81,8 @@ public Builder context(Object context) {
         }
 
         public <K> Builder keyContexts(List<K> keys, List<Object> keyContexts) {
-            nonNull(keys);
-            nonNull(keyContexts);
+            requireNonNull(keys);
+            requireNonNull(keyContexts);
 
             Map<Object, Object> map = new HashMap<>();
             List<Object> list = new ArrayList<>();

src/main/java/org/dataloader/BatchLoaderEnvironmentProvider.java

@@ -1,5 +1,7 @@
 package org.dataloader;
 
+import org.dataloader.annotations.PublicSpi;
+
 /**
  * A BatchLoaderEnvironmentProvider is used by the {@link org.dataloader.DataLoader} code to
  * provide {@link org.dataloader.BatchLoaderEnvironment} calling context to

src/main/java/org/dataloader/BatchLoaderWithContext.java

@@ -1,5 +1,7 @@
 package org.dataloader;
 
+import org.dataloader.annotations.PublicSpi;
+
 import java.util.List;
 import java.util.concurrent.CompletionStage;
 

src/main/java/org/dataloader/CacheMap.java

@@ -16,10 +16,9 @@
 
 package org.dataloader;
 
+import org.dataloader.annotations.PublicSpi;
 import org.dataloader.impl.DefaultCacheMap;
 
-import java.util.concurrent.CompletableFuture;
-
 /**
  * Cache map interface for data loaders that use caching.
  * <p>
@@ -31,7 +30,6 @@
  *
  * @param <U> type parameter indicating the type of the cache keys
  * @param <V> type parameter indicating the type of the data that is cached
- *
  * @author <a href="https://github.com/aschrijver/">Arnold Schrijver</a>
  * @author <a href="https://github.com/bbakerman/">Brad Baker</a>
  */
@@ -43,18 +41,16 @@ public interface CacheMap<U, V> {
      *
      * @param <U> type parameter indicating the type of the cache keys
      * @param <V> type parameter indicating the type of the data that is cached
-     *
      * @return the cache map
      */
-    static <U, V> CacheMap<U, CompletableFuture<V>> simpleMap() {
+    static <U, V> CacheMap<U, V> simpleMap() {
         return new DefaultCacheMap<>();
     }
 
     /**
      * Checks whether the specified key is contained in the cach map.
      *
      * @param key the key to check
-     *
      * @return {@code true} if the cache contains the key, {@code false} otherwise
      */
     boolean containsKey(U key);
@@ -66,7 +62,6 @@ static <U, V> CacheMap<U, CompletableFuture<V>> simpleMap() {
      * so be sure to check {@link CacheMap#containsKey(Object)} first.
      *
      * @param key the key to retrieve
-     *
      * @return the cached value, or {@code null} if not found (depends on cache implementation)
      */
     V get(U key);
@@ -76,7 +71,6 @@ static <U, V> CacheMap<U, CompletableFuture<V>> simpleMap() {
      *
      * @param key   the key to cache
      * @param value the value to cache
-     *
      * @return the cache map for fluent coding
      */
     CacheMap<U, V> set(U key, V value);
@@ -85,7 +79,6 @@ static <U, V> CacheMap<U, CompletableFuture<V>> simpleMap() {
      * Deletes the entry with the specified key from the cache map, if it exists.
      *
      * @param key the key to delete
-     *
      * @return the cache map for fluent coding
      */
     CacheMap<U, V> delete(U key);