annotate Registry methods with nullability and contract

common/api/registry/src/main/java/com/dfsek/terra/api/registry/CheckedRegistry.java

@@ -9,6 +9,8 @@ package com.dfsek.terra.api.registry;
 
 import com.dfsek.terra.api.registry.exception.DuplicateEntryException;
 
+import org.jetbrains.annotations.NotNull;
+
 
 public interface CheckedRegistry<T> extends Registry<T> {
     /**
@@ -19,6 +21,5 @@ public interface CheckedRegistry<T> extends Registry<T> {
      *
      * @throws DuplicateEntryException If an entry with the same identifier is already present.
      */
-    void register(String identifier, T value) throws DuplicateEntryException;
+    void register(@NotNull String identifier, @NotNull T value) throws DuplicateEntryException;
-    
 }

common/api/registry/src/main/java/com/dfsek/terra/api/registry/OpenRegistry.java

@@ -9,6 +9,8 @@ package com.dfsek.terra.api.registry;
 
 import com.dfsek.terra.api.registry.exception.DuplicateEntryException;
 
+import org.jetbrains.annotations.NotNull;
+
 
 public interface OpenRegistry<T> extends Registry<T> {
     /**
@@ -17,7 +19,7 @@ public interface OpenRegistry<T> extends Registry<T> {
      * @param identifier Identifier to assign value.
      * @param value      Value to register.
      */
-    boolean register(String identifier, T value);
+    boolean register(@NotNull String identifier, @NotNull T value);
     
     /**
      * Add a value to this registry, checking whether it is present first.
@@ -27,7 +29,7 @@ public interface OpenRegistry<T> extends Registry<T> {
      *
      * @throws DuplicateEntryException If an entry with the same identifier is already present.
      */
-    void registerChecked(String identifier, T value) throws DuplicateEntryException;
+    void registerChecked(@NotNull String identifier, @NotNull T value) throws DuplicateEntryException;
     
     /**
      * Clears all entries from the registry.

common/api/registry/src/main/java/com/dfsek/terra/api/registry/Registry.java

@@ -9,6 +9,11 @@ package com.dfsek.terra.api.registry;
 
 import com.dfsek.tectonic.loading.TypeLoader;
 
+import com.dfsek.terra.api.registry.exception.NoSuchEntryException;
+
+import org.jetbrains.annotations.Contract;
+import org.jetbrains.annotations.NotNull;
+
 import java.util.Collection;
 import java.util.Set;
 import java.util.function.BiConsumer;
@@ -23,7 +28,9 @@ public interface Registry<T> extends TypeLoader<T> {
      *
      * @return Value matching the identifier, {@code null} if no value is present.
      */
-    T get(String identifier);
+    @NotNull
+    @Contract(pure = true)
+    T get(@NotNull String identifier) throws NoSuchEntryException;
     
     /**
      * Check if the registry contains a value.
@@ -32,27 +39,30 @@ public interface Registry<T> extends TypeLoader<T> {
      *
      * @return Whether the registry contains the value.
      */
-    boolean contains(String identifier);
+    @Contract(pure = true)
+    boolean contains(@NotNull String identifier);
     
     /**
      * Perform the given action for every value in the registry.
      *
      * @param consumer Action to perform on value.
      */
-    void forEach(Consumer<T> consumer);
+    void forEach(@NotNull Consumer<T> consumer);
     
     /**
      * Perform an action for every key-value pair in the registry.
      *
      * @param consumer Action to perform on pair.
      */
-    void forEach(BiConsumer<String, T> consumer);
+    void forEach(@NotNull BiConsumer<String, T> consumer);
     
     /**
      * Get the entries of this registry as a {@link Set}.
      *
      * @return Set containing all entries.
      */
+    @NotNull
+    @Contract(pure = true)
     Collection<T> entries();
     
     /**
@@ -60,5 +70,7 @@ public interface Registry<T> extends TypeLoader<T> {
      *
      * @return Keys in registry
      */
+    @NotNull
+    @Contract(pure = true)
     Set<String> keys();
 }

common/api/registry/src/main/java/com/dfsek/terra/api/registry/exception/NoSuchEntryException.java

@@ -0,0 +1,11 @@
+package com.dfsek.terra.api.registry.exception;
+
+public class NoSuchEntryException extends RuntimeException {
+    public NoSuchEntryException(String message) {
+        super(message);
+    }
+    
+    public NoSuchEntryException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

common/implementation/base/src/main/java/com/dfsek/terra/registry/CheckedRegistryImpl.java

@@ -29,6 +29,7 @@ import java.util.function.Consumer;
 import com.dfsek.terra.api.registry.CheckedRegistry;
 import com.dfsek.terra.api.registry.OpenRegistry;
 import com.dfsek.terra.api.registry.exception.DuplicateEntryException;
+import org.jetbrains.annotations.NotNull;
 
 
 /**
@@ -44,37 +45,37 @@ public class CheckedRegistryImpl<T> implements CheckedRegistry<T> {
     }
     
     @Override
-    public void register(String identifier, T value) throws DuplicateEntryException {
+    public void register(@NotNull String identifier, @NotNull T value) throws DuplicateEntryException {
         registry.registerChecked(identifier, value);
     }
     
     @Override
-    public T get(String identifier) {
+    public @NotNull T get(@NotNull String identifier) {
         return registry.get(identifier);
     }
     
     @Override
-    public boolean contains(String identifier) {
+    public boolean contains(@NotNull String identifier) {
         return registry.contains(identifier);
     }
     
     @Override
-    public void forEach(Consumer<T> consumer) {
+    public void forEach(@NotNull Consumer<T> consumer) {
         registry.forEach(consumer);
     }
     
     @Override
-    public void forEach(BiConsumer<String, T> consumer) {
+    public void forEach(@NotNull BiConsumer<String, T> consumer) {
         registry.forEach(consumer);
     }
     
     @Override
-    public Collection<T> entries() {
+    public @NotNull Collection<T> entries() {
         return registry.entries();
     }
     
     @Override
-    public Set<String> keys() {
+    public @NotNull Set<String> keys() {
         return registry.keys();
     }
     

common/implementation/base/src/main/java/com/dfsek/terra/registry/LockedRegistryImpl.java

@@ -28,6 +28,8 @@ import java.util.function.Consumer;
 
 import com.dfsek.terra.api.registry.Registry;
 
+import org.jetbrains.annotations.NotNull;
+
 
 /**
  * Wrapper for a registry that forbids all write access.
@@ -42,32 +44,32 @@ public class LockedRegistryImpl<T> implements Registry<T> {
     }
     
     @Override
-    public T get(String identifier) {
+    public @NotNull T get(@NotNull String identifier) {
         return registry.get(identifier);
     }
     
     @Override
-    public boolean contains(String identifier) {
+    public boolean contains(@NotNull String identifier) {
         return registry.contains(identifier);
     }
     
     @Override
-    public void forEach(Consumer<T> consumer) {
+    public void forEach(@NotNull Consumer<T> consumer) {
         registry.forEach(consumer);
     }
     
     @Override
-    public void forEach(BiConsumer<String, T> consumer) {
+    public void forEach(@NotNull BiConsumer<String, T> consumer) {
         registry.forEach(consumer);
     }
     
     @Override
-    public Collection<T> entries() {
+    public @NotNull Collection<T> entries() {
         return registry.entries();
     }
     
     @Override
-    public Set<String> keys() {
+    public @NotNull Set<String> keys() {
         return registry.keys();
     }
     

common/implementation/base/src/main/java/com/dfsek/terra/registry/OpenRegistryImpl.java

@@ -34,6 +34,10 @@ import java.util.stream.Collectors;
 import com.dfsek.terra.api.registry.OpenRegistry;
 import com.dfsek.terra.api.registry.exception.DuplicateEntryException;
 
+import com.dfsek.terra.api.registry.exception.NoSuchEntryException;
+
+import org.jetbrains.annotations.NotNull;
+
 
 /**
  * Registry implementation with read/write access. For internal use only.
@@ -55,24 +59,26 @@ public class OpenRegistryImpl<T> implements OpenRegistry<T> {
     
     @Override
     public T load(AnnotatedType type, Object o, ConfigLoader configLoader) throws LoadException {
-        T obj = get((String) o);
+        T obj;
-        String list = objects.keySet().stream().sorted().reduce("", (a, b) -> a + "\n - " + b);
+        try {
-        
+            obj = get((String) o);
-        if(objects.isEmpty()) list = "[ ]";
+        } catch(NoSuchEntryException e) {
-        
+            String list = objects.keySet().stream().sorted().reduce("", (a, b) -> a + "\n - " + b);
-        if(obj == null)
+            if(objects.isEmpty()) list = "[ ]";
             throw new LoadException("No such " + type.getType().getTypeName() + " matching \"" + o +
                                     "\" was found in this registry. Registry contains items: " + list);
+        }
+        
         return obj;
     }
     
     @Override
-    public boolean register(String identifier, T value) {
+    public boolean register(@NotNull String identifier, @NotNull T value) {
         return register(identifier, new Entry<>(value));
     }
     
     @Override
-    public void registerChecked(String identifier, T value) throws DuplicateEntryException {
+    public void registerChecked(@NotNull String identifier, @NotNull T value) throws DuplicateEntryException {
         if(objects.containsKey(identifier))
             throw new DuplicateEntryException("Value with identifier \"" + identifier + "\" is already defined in registry.");
         register(identifier, value);
@@ -95,32 +101,36 @@ public class OpenRegistryImpl<T> implements OpenRegistry<T> {
     
     @SuppressWarnings("unchecked")
     @Override
-    public T get(String identifier) {
+    public @NotNull T get(@NotNull String identifier) {
-        return objects.getOrDefault(identifier, (Entry<T>) NULL).getValue();
+        T value = objects.getOrDefault(identifier, (Entry<T>) NULL).getValue();
+        if(value == null) {
+            throw new NoSuchEntryException("Entry " + identifier + " is not present in registry.");
+        }
+        return value;
     }
     
     @Override
-    public boolean contains(String identifier) {
+    public boolean contains(@NotNull String identifier) {
         return objects.containsKey(identifier);
     }
     
     @Override
-    public void forEach(Consumer<T> consumer) {
+    public void forEach(@NotNull Consumer<T> consumer) {
         objects.forEach((id, obj) -> consumer.accept(obj.getRaw()));
     }
     
     @Override
-    public void forEach(BiConsumer<String, T> consumer) {
+    public void forEach(@NotNull BiConsumer<String, T> consumer) {
         objects.forEach((id, entry) -> consumer.accept(id, entry.getRaw()));
     }
     
     @Override
-    public Collection<T> entries() {
+    public @NotNull Collection<T> entries() {
         return objects.values().stream().map(Entry::getRaw).collect(Collectors.toList());
     }
     
     @Override
-    public Set<String> keys() {
+    public @NotNull Set<String> keys() {
         return objects.keySet();
     }