Start outfitting core classes for Guice

[rhynodge.git] / src / main / java / net / pterodactylus / rhynodge / states / StateManager.java

diff --git a/src/main/java/net/pterodactylus/rhynodge/states/StateManager.java b/src/main/java/net/pterodactylus/rhynodge/states/StateManager.java
index 19eccba..bb8aff5 100644 (file)
--- a/src/main/java/net/pterodactylus/rhynodge/states/StateManager.java
+++ b/src/main/java/net/pterodactylus/rhynodge/states/StateManager.java
@@ -17,8 +17,15 @@
 
 package net.pterodactylus.rhynodge.states;
 
+import static java.util.Optional.empty;
+import static java.util.Optional.ofNullable;
+
 import java.io.File;
 import java.io.IOException;
+import java.util.Optional;
+
+import javax.inject.Inject;
+import javax.inject.Singleton;
 
 import net.pterodactylus.rhynodge.State;
 
@@ -34,6 +41,7 @@ import com.fasterxml.jackson.databind.ObjectMapper;
  *
  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  */
+@Singleton
 public class StateManager {
 
        /** The logger. */
@@ -51,8 +59,9 @@ public class StateManager {
         * @param directory
         *            The directory to store states in
         */
-       public StateManager(String directory) {
-               this.directory = directory;
+       @Inject
+       public StateManager(Directory directory) {
+               this.directory = directory.getDirectory();
        }
 
        //
@@ -64,10 +73,10 @@ public class StateManager {
         *
         * @param reactionName
         *            The name of the reaction
-        * @return The loaded state, or {@code null} if the state could not be
+        * @return The loaded state, or {@link Optional#empty()} if the state could not be
         *         loaded
         */
-       public State loadLastState(String reactionName) {
+       public Optional<State> loadLastState(String reactionName) {
                return loadLastState(reactionName, false);
        }
 
@@ -76,10 +85,10 @@ public class StateManager {
         *
         * @param reactionName
         *            The name of the reaction
-        * @return The loaded state, or {@code null} if the state could not be
+        * @return The loaded state, or {@link Optional#empty()} if the state could not be
         *         loaded
         */
-       public State loadLastSuccessfulState(String reactionName) {
+       public Optional<State> loadLastSuccessfulState(String reactionName) {
                return loadLastState(reactionName, true);
        }
 
@@ -92,8 +101,9 @@ public class StateManager {
         *            The state to save
         */
        public void saveState(String reactionName, State state) {
+               File stateFile = null;
                try {
-                       File stateFile = stateFile(reactionName, "last");
+                       stateFile = stateFile(reactionName, "last");
                        objectMapper.writeValue(stateFile, state);
                        if (state.success()) {
                                stateFile = stateFile(reactionName, "success");
@@ -101,10 +111,13 @@ public class StateManager {
                        }
                } catch (JsonGenerationException jge1) {
                        logger.warn(String.format("State for Reaction “%s” could not be generated.", reactionName), jge1);
+                       stateFile.delete();
                } catch (JsonMappingException jme1) {
                        logger.warn(String.format("State for Reaction “%s” could not be generated.", reactionName), jme1);
+                       stateFile.delete();
                } catch (IOException ioe1) {
                        logger.warn(String.format("State for Reaction “%s” could not be written.", reactionName));
+                       stateFile.delete();
                }
        }
 
@@ -133,14 +146,14 @@ public class StateManager {
         * @param successful
         *            {@code true} to load the last successful state, {@code false}
         *            to load the last state
-        * @return The loaded state, or {@code null} if the state could not be
+        * @return The loaded state, or {@link Optional#empty()} if the state could not be
         *         loaded
         */
-       private State loadLastState(String reactionName, boolean successful) {
+       private Optional<State> loadLastState(String reactionName, boolean successful) {
                File stateFile = stateFile(reactionName, successful ? "success" : "last");
                try {
                        State state = objectMapper.readValue(stateFile, AbstractState.class);
-                       return state;
+                       return ofNullable(state);
                } catch (JsonParseException jpe1) {
                        logger.warn(String.format("State for Reaction “%s” could not be parsed.", reactionName), jpe1);
                } catch (JsonMappingException jme1) {
@@ -148,7 +161,25 @@ public class StateManager {
                } catch (IOException ioe1) {
                        logger.info(String.format("State for Reaction “%s” could not be found.", reactionName));
                }
-               return null;
+               return empty();
+       }
+
+       public static class Directory {
+
+               private final String directory;
+
+               private Directory(String directory) {
+                       this.directory = directory;
+               }
+
+               public String getDirectory() {
+                       return directory;
+               }
+
+               public static Directory of(String directory) {
+                       return new Directory(directory);
+               }
+
        }
 
 }