added loadAndSave method

ConfigLib-Core/src/main/java/de/exlll/configlib/Configuration.java

@@ -1,44 +1,84 @@
 package de.exlll.configlib;
 
+import org.yaml.snakeyaml.parser.ParserException;
+
 import java.io.IOException;
 import java.nio.file.Files;
+import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
 import java.util.Map;
 import java.util.Objects;
 
 public abstract class Configuration {
     private final Path configPath;
-    private final Comments comments;
     private final FieldMapper fieldMapper;
+    private final ConfigurationWriter writer;
 
     public Configuration(Path configPath) {
         Objects.requireNonNull(configPath);
-        this.configPath = configPath;
+
         FilteredFieldStreamSupplier ffss = new FilteredFieldStreamSupplier(
                 getClass(), ConfigurationFieldFilter.INSTANCE);
-        this.comments = Comments.from(ffss);
+        Comments comments = Comments.from(ffss);
+
+        this.configPath = configPath;
         this.fieldMapper = new FieldMapper(ffss);
+        this.writer = new ConfigurationWriter(configPath, comments);
     }
 
+    /**
+     * Loads the configuration file from the specified {@code Path} and sets {@code this} fields.
+     *
+     * @throws ClassCastException if parsed Object is not a {@code Map}
+     * @throws IOException        if an I/O error occurs when loading the configuration file.
+     * @throws ParserException    if invalid YAML
+     */
+    public final void load() throws IOException {
+        String dump = new ConfigurationReader(configPath).read();
+        Map<String, Object> valuesByFieldNames = YamlSerializer.deserialize(dump);
+        fieldMapper.mapValuesToFields(valuesByFieldNames, this);
+    }
+
+    /**
+     * Saves {@code this} fields and {@code @Comment} annotations to a configuration file at the specified {@code Path}.
+     * <p>
+     * Fields which are {@code final}, {@code static} or {@code transient} are ignored.
+     * <p>
+     * If the file exists, it is overriden; otherwise, it is created.
+     *
+     * @throws IOException     if an I/O error occurs when saving the configuration file.
+     * @throws ParserException if invalid YAML
+     */
     public final void save() throws IOException {
         createParentDirectories();
 
-        Map<String, Object> valuesByFieldNames = fieldMapper
+        Map<String, Object> valuesByFieldNames = fieldMapper.mapFieldNamesToValues(this);
-                .mapFieldNamesToValues(this);
         String dump = YamlSerializer.serialize(valuesByFieldNames);
-        ConfigurationWriter writer = new ConfigurationWriter(configPath, comments);
         writer.write(dump);
     }
 
+    /**
+     * Loads and saves the configuration file.
+     *
+     * @throws ClassCastException if parsed Object is not a {@code Map}
+     * @throws IOException        if an I/O error occurs when loading or saving the configuration file.
+     * @throws ParserException    if invalid YAML
+     * @see #load()
+     * @see #save()
+     */
+    public final void loadAndSave() throws IOException {
+        try {
+            load();
+            save();
+        } catch (NoSuchFileException e) {
+            save();
+        }
+    }
+
     private void createParentDirectories() throws IOException {
         Path parentDirectory = configPath.getParent();
+        if (Files.notExists(parentDirectory)) {
             Files.createDirectories(parentDirectory);
         }
-
-    public final void load() throws IOException {
-        // TODO save if not existent
-        String dump = new ConfigurationReader(configPath).read();
-        Map<String, Object> valuesByFieldNames = YamlSerializer.deserialize(dump);
-        fieldMapper.mapValuesToFields(valuesByFieldNames, this);
     }
 }

ConfigLib-Core/src/test/java/de/exlll/configlib/ConfigurationTest.java

@@ -67,13 +67,20 @@ public class ConfigurationTest {
     public void load() throws Exception {
         new OriginalTestClass(filePath).save();
         ChangedTestClass cls = new ChangedTestClass(filePath);
-        cls.load();
+        cls.loadAndSave();
 
         assertThat(cls.a, is(0));
         assertThat(cls.b, is(1));
         assertThat(cls.c, is(4));
     }
 
+    @Test
+    public void loadAndSaveSavesFile() throws Exception {
+        new OriginalTestClass(filePath).loadAndSave();
+
+        assertThat(Files.exists(filePath), is(true));
+    }
+
     private static final class OriginalTestClass extends Configuration {
         private int a = 0;
         private int b = 1;

README.md

@@ -11,11 +11,17 @@ This library facilitates the creation, saving and loading of YAML configuration
 
 ## How-to
 ##### Creating a configuration
-To create a new configuration, you need a class which extends `Configuration`. Instances of this 
+To create a new configuration, create a class which extends `Configuration`. Fields which are
-class have a `load` and a `save` method. Calling `save` dumps all fields which are not 
+added to this class and which are not `final`, `static` or `transient` can automatically be saved
-`final`, `static` or `transient` to a configuration file. If the file is present, it is overriden; 
+ to the corresponding configuration file.
-otherwise, it is created. The `load` method tries to load the configuration file. If it fails 
+
-because the file doesn't exist, it calls `save` and then tries again.
+##### Saving and loading a configuration
+Instances of your configuration class have a `load`, `save` and `loadAndSave` method:
+- `save` dumps all fields which are not `final`, `static` or `transient` to a configuration file.
+  If the file exists, it is overriden; otherwise, it is created.
+- `load` reads the configuration file and updates the instance's values.
+- `loadAndSave` loads the configuration file and then calls `save` to update the file's values.
+If the file doesn't exist, it is saved.
 
 ##### Adding and removing fields
 In order to add or to remove fields, you just need to add them to or remove them from your
@@ -66,7 +72,7 @@ public class Plugin {
     
         DatabaseConfig config = new DatabaseConfig(path);
         try {
-            config.load();
+            config.loadAndSave();
         } catch (IOException e) {
             /* do something with exception */
         }