Refactor Storage components

src/main/java/seedu/address/MainApp.java

@@ -15,13 +15,9 @@
 import seedu.address.commons.util.StringUtil;
 import seedu.address.logic.Logic;
 import seedu.address.logic.LogicManager;
-import seedu.address.model.AddressBook;
 import seedu.address.model.Model;
 import seedu.address.model.ModelManager;
-import seedu.address.model.ReadOnlyAddressBook;
-import seedu.address.model.ReadOnlyUserPrefs;
 import seedu.address.model.UserPrefs;
-import seedu.address.model.util.SampleDataUtil;
 import seedu.address.storage.AddressBookStorage;
 import seedu.address.storage.JsonAddressBookStorage;
 import seedu.address.storage.JsonUserPrefsStorage;
@@ -60,39 +56,13 @@
         AddressBookStorage addressBookStorage = new JsonAddressBookStorage(userPrefs.getAddressBookFilePath());
         storage = new StorageManager(addressBookStorage, userPrefsStorage);
 
-        model = initModelManager(storage, userPrefs);
+        model = new ModelManager(storage.readInitialAddressBook(), userPrefs);
 
         logic = new LogicManager(model, storage);
 
         ui = new UiManager(logic);
     }
 
-    /**
-     * Returns a {@code ModelManager} with the data from {@code storage}'s address book and {@code userPrefs}. <br>
-     * The data from the sample address book will be used instead if {@code storage}'s address book is not found,
-     * or an empty address book will be used instead if errors occur when reading {@code storage}'s address book.
-     */
-    private Model initModelManager(Storage storage, ReadOnlyUserPrefs userPrefs) {
-        logger.info("Using data file : " + storage.getAddressBookFilePath());
-
-        Optional<ReadOnlyAddressBook> addressBookOptional;
-        ReadOnlyAddressBook initialData;
-        try {
-            addressBookOptional = storage.readAddressBook();
-            if (!addressBookOptional.isPresent()) {
-                logger.info("Creating a new data file " + storage.getAddressBookFilePath()
-                        + " populated with a sample AddressBook.");
-            }
-            initialData = addressBookOptional.orElseGet(SampleDataUtil::getSampleAddressBook);
-        } catch (DataLoadingException e) {
-            logger.warning("Data file at " + storage.getAddressBookFilePath() + " could not be loaded."
-                    + " Will be starting with an empty AddressBook.");
-            initialData = new AddressBook();
-        }
-
-        return new ModelManager(initialData, userPrefs);
-    }
-
     private void initLogging(Config config) {
         LogsCenter.init(config);
     }
@@ -117,7 +87,7 @@
 
         try {
             Optional<Config> configOptional = ConfigUtil.readConfig(configFilePathUsed);
-            if (!configOptional.isPresent()) {
+            if (configOptional.isEmpty()) {
                 logger.info("Creating new config file " + configFilePathUsed);
             }
             initializedConfig = configOptional.orElse(new Config());
@@ -148,7 +118,7 @@
         UserPrefs initializedPrefs;
         try {
             Optional<UserPrefs> prefsOptional = storage.readUserPrefs();
-            if (!prefsOptional.isPresent()) {
+            if (prefsOptional.isEmpty()) {
                 logger.info("Creating new preference file " + prefsFilePath);
             }
             initializedPrefs = prefsOptional.orElse(new UserPrefs());

src/main/java/seedu/address/logic/Logic.java

@@ -6,8 +6,8 @@
 import seedu.address.commons.core.GuiSettings;
 import seedu.address.logic.commands.exceptions.CommandException;
 import seedu.address.logic.parser.exceptions.ParseException;
-import seedu.address.model.ReadOnlyAddressBook;
 import seedu.address.model.person.Person;
+import seedu.address.storage.exceptions.StorageException;
 
 /**
  * API of the Logic component
@@ -20,14 +20,8 @@ public interface Logic {
      * @throws CommandException If an error occurs during command execution.
      * @throws ParseException If an error occurs during parsing.
      */
-    String execute(String commandText) throws CommandException, ParseException;
 
-    /**
-     * Returns the AddressBook.
-     *
-     * @see seedu.address.model.Model#getAddressBook()
-     */
-    ReadOnlyAddressBook getAddressBook();
+    String execute(String commandText) throws CommandException, ParseException, StorageException;
 
     /** Returns an unmodifiable view of the filtered list of persons */
     ObservableList<Person> getFilteredPersonList();

src/main/java/seedu/address/logic/LogicManager.java

@@ -1,7 +1,5 @@
 package seedu.address.logic;
 
-import java.io.IOException;
-import java.nio.file.AccessDeniedException;
 import java.nio.file.Path;
 import java.util.logging.Logger;
 
@@ -13,19 +11,14 @@
 import seedu.address.logic.parser.AddressBookParser;
 import seedu.address.logic.parser.exceptions.ParseException;
 import seedu.address.model.Model;
-import seedu.address.model.ReadOnlyAddressBook;
 import seedu.address.model.person.Person;
 import seedu.address.storage.Storage;
+import seedu.address.storage.exceptions.StorageException;
 
 /**
  * The main LogicManager of the app.
  */
 public class LogicManager implements Logic {
-    public static final String FILE_OPS_ERROR_FORMAT = "Could not save data due to the following error: %s";
-
-    public static final String FILE_OPS_PERMISSION_ERROR_FORMAT =
-            "Could not save data to file %s due to insufficient permissions to write to the file or the folder.";
-
     private final Logger logger = LogsCenter.getLogger(LogicManager.class);
 
     private final Model model;
@@ -40,28 +33,16 @@ public LogicManager(Model model, Storage storage) {
     }
 
     @Override
-    public String execute(String commandText) throws CommandException, ParseException {
+    public String execute(String commandText) throws CommandException, ParseException, StorageException {
         logger.info("----------------[USER COMMAND][" + commandText + "]");
 
         Command command = AddressBookParser.parseCommand(commandText);
         String commandResult = command.execute(model);
-
-        try {
-            storage.saveAddressBook(model.getAddressBook());
-        } catch (AccessDeniedException e) {
-            throw new CommandException(String.format(FILE_OPS_PERMISSION_ERROR_FORMAT, e.getMessage()), e);
-        } catch (IOException ioe) {
-            throw new CommandException(String.format(FILE_OPS_ERROR_FORMAT, ioe.getMessage()), ioe);
-        }
+        storage.saveAddressBook(model.getAddressBook());
 
         return commandResult;
     }
 
-    @Override
-    public ReadOnlyAddressBook getAddressBook() {
-        return model.getAddressBook();
-    }
-
     @Override
     public ObservableList<Person> getFilteredPersonList() {
         return model.getFilteredPersonList();

src/main/java/seedu/address/storage/AddressBookStorage.java

@@ -1,11 +1,11 @@
 package seedu.address.storage;
 
-import java.io.IOException;
 import java.nio.file.Path;
 import java.util.Optional;
 
 import seedu.address.commons.exceptions.DataLoadingException;
 import seedu.address.model.ReadOnlyAddressBook;
+import seedu.address.storage.exceptions.StorageException;
 
 /**
  * Represents a storage for {@link seedu.address.model.AddressBook}.
@@ -33,13 +33,13 @@ public interface AddressBookStorage {
     /**
      * Saves the given {@link ReadOnlyAddressBook} to the storage.
      * @param addressBook cannot be null.
-     * @throws IOException if there was any problem writing to the file.
+     * @throws StorageException if there was any problem writing to the file.
      */
-    void saveAddressBook(ReadOnlyAddressBook addressBook) throws IOException;
+    void saveAddressBook(ReadOnlyAddressBook addressBook) throws StorageException;
 
     /**
      * @see #saveAddressBook(ReadOnlyAddressBook)
      */
-    void saveAddressBook(ReadOnlyAddressBook addressBook, Path filePath) throws IOException;
+    void saveAddressBook(ReadOnlyAddressBook addressBook, Path filePath) throws StorageException;
 
 }

src/main/java/seedu/address/storage/JsonAddressBookStorage.java

@@ -3,6 +3,7 @@
 import static java.util.Objects.requireNonNull;
 
 import java.io.IOException;
+import java.nio.file.AccessDeniedException;
 import java.nio.file.Path;
 import java.util.Optional;
 import java.util.logging.Logger;
@@ -13,11 +14,17 @@
 import seedu.address.commons.util.JsonUtil;
 import seedu.address.model.AddressBook;
 import seedu.address.model.ReadOnlyAddressBook;
+import seedu.address.storage.exceptions.StorageException;
 
 /**
  * A class to access AddressBook data stored as a json file on the hard disk.
  */
 public class JsonAddressBookStorage implements AddressBookStorage {
+    public static final String FILE_OPS_ERROR_FORMAT = "Could not save data due to the following error: %s";
+
+    public static final String FILE_OPS_PERMISSION_ERROR_FORMAT =
+            "Could not save data to file %s due to insufficient permissions to write to the file or the folder.";
+
 
     private static final Logger logger = LogsCenter.getLogger(JsonAddressBookStorage.class);
 
@@ -46,14 +53,11 @@
         requireNonNull(filePath);
 
         Optional<AddressBook> addressBook = JsonUtil.readJsonFile(filePath, AddressBook.class);
-        if (!addressBook.isPresent()) {
-            return Optional.empty();
-        }
-        return Optional.of(addressBook.get());
+        return addressBook.map(value -> value);
     }
 
     @Override
-    public void saveAddressBook(ReadOnlyAddressBook addressBook) throws IOException {
+    public void saveAddressBook(ReadOnlyAddressBook addressBook) throws StorageException {
         saveAddressBook(addressBook, filePath);
     }
 
@@ -62,12 +66,19 @@
      *
      * @param filePath location of the data. Cannot be null.
      */
-    public void saveAddressBook(ReadOnlyAddressBook addressBook, Path filePath) throws IOException {
+    public void saveAddressBook(ReadOnlyAddressBook addressBook, Path filePath) throws StorageException {
         requireNonNull(addressBook);
         requireNonNull(filePath);
 
-        FileUtil.createIfMissing(filePath);
-        JsonUtil.saveJsonFile(addressBook, filePath);
+        try {
+            FileUtil.createIfMissing(filePath);
+            JsonUtil.saveJsonFile(addressBook, filePath);
+        } catch (AccessDeniedException e) {
+            throw new StorageException(String.format(FILE_OPS_PERMISSION_ERROR_FORMAT, e.getMessage()), e);
+        } catch (IOException ioe) {
+            throw new StorageException(String.format(FILE_OPS_ERROR_FORMAT, ioe.getMessage()), ioe);
+        }
+
     }
 
 }

src/main/java/seedu/address/storage/Storage.java

@@ -8,6 +8,7 @@
 import seedu.address.model.ReadOnlyAddressBook;
 import seedu.address.model.ReadOnlyUserPrefs;
 import seedu.address.model.UserPrefs;
+import seedu.address.storage.exceptions.StorageException;
 
 /**
  * API of the Storage component
@@ -27,6 +28,7 @@ public interface Storage extends AddressBookStorage, UserPrefsStorage {
     Optional<ReadOnlyAddressBook> readAddressBook() throws DataLoadingException;
 
     @Override
-    void saveAddressBook(ReadOnlyAddressBook addressBook) throws IOException;
+    void saveAddressBook(ReadOnlyAddressBook addressBook) throws StorageException;
 
+    ReadOnlyAddressBook readInitialAddressBook();
 }

src/main/java/seedu/address/storage/StorageManager.java

@@ -7,15 +7,17 @@
 
 import seedu.address.commons.core.LogsCenter;
 import seedu.address.commons.exceptions.DataLoadingException;
+import seedu.address.model.AddressBook;
 import seedu.address.model.ReadOnlyAddressBook;
 import seedu.address.model.ReadOnlyUserPrefs;
 import seedu.address.model.UserPrefs;
+import seedu.address.model.util.SampleDataUtil;
+import seedu.address.storage.exceptions.StorageException;
 
 /**
  * Manages storage of AddressBook data in local storage.
  */
 public class StorageManager implements Storage {
-
     private static final Logger logger = LogsCenter.getLogger(StorageManager.class);
     private AddressBookStorage addressBookStorage;
     private UserPrefsStorage userPrefsStorage;
@@ -65,14 +67,42 @@
     }
 
     @Override
-    public void saveAddressBook(ReadOnlyAddressBook addressBook) throws IOException {
+    public void saveAddressBook(ReadOnlyAddressBook addressBook) throws StorageException {
         saveAddressBook(addressBook, addressBookStorage.getAddressBookFilePath());
     }
 
     @Override
-    public void saveAddressBook(ReadOnlyAddressBook addressBook, Path filePath) throws IOException {
+    public void saveAddressBook(ReadOnlyAddressBook addressBook, Path filePath) throws StorageException {
         logger.fine("Attempting to write to data file: " + filePath);
         addressBookStorage.saveAddressBook(addressBook, filePath);
     }
 
+    /**
+     * Returns a {@code ReadOnlyAddressBook} with the initial data from {@code addressBookStorage}. <br>
+     * The data from the sample address book will be used instead if {@code addressBookStorage}'s address book is not
+     * found, or an empty address book will be used instead if errors occur when reading {@code addressBookStorage}'s
+     * address book.
+     */
+    @Override
+    public ReadOnlyAddressBook readInitialAddressBook() {
+        logger.info("Using data file : " + getAddressBookFilePath());
+
+        Optional<ReadOnlyAddressBook> addressBookOptional;
+        ReadOnlyAddressBook initialAddressBook;
+        try {
+            addressBookOptional = readAddressBook();
+            if (addressBookOptional.isEmpty()) {
+                logger.info("Creating a new data file " + getAddressBookFilePath()
+                        + " populated with a sample AddressBook.");
+            }
+            initialAddressBook = addressBookOptional.orElseGet(SampleDataUtil::getSampleAddressBook);
+        } catch (DataLoadingException e) {
+            logger.warning("Data file at " + getAddressBookFilePath() + " could not be loaded."
+                    + " Will be starting with an empty AddressBook.");
+            initialAddressBook = new AddressBook();
+        }
+
+        return initialAddressBook;
+    }
+
 }

src/main/java/seedu/address/storage/exceptions/StorageException.java

@@ -0,0 +1,14 @@
+package seedu.address.storage.exceptions;
+
+/**
+ * Represents a storage error encountered by Storage.
+ */
+public class StorageException extends Exception {
+    public StorageException(String message) {
+        super(message);
+    }
+
+    public StorageException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}

src/main/java/seedu/address/ui/CommandBox.java

@@ -6,6 +6,7 @@
 import javafx.scene.layout.Region;
 import seedu.address.logic.commands.exceptions.CommandException;
 import seedu.address.logic.parser.exceptions.ParseException;
+import seedu.address.storage.exceptions.StorageException;
 
 /**
  * The UI component that is responsible for receiving user command inputs.
@@ -43,7 +44,7 @@
         try {
             commandExecutor.execute(commandText);
             commandTextField.setText("");
-        } catch (CommandException | ParseException e) {
+        } catch (CommandException | ParseException | StorageException e) {
             setStyleToIndicateCommandFailure();
         }
     }
@@ -78,7 +79,7 @@
          *
          * @see seedu.address.logic.Logic#execute(String)
          */
-        String execute(String commandText) throws CommandException, ParseException;
+        String execute(String commandText) throws CommandException, ParseException, StorageException;
     }
 
 }