feat: Add Configuration.Builder load() method to load a file or resource (#131)

This then allows programmatic creation of Configuration which include the loading of files or resources like:

    var fileSource = new File("./src/test/resources/yaml/minimal.yaml");

    var configuration = Configuration.builder()
      .put("myExtraOne", "baz")
      .load(fileSource)          // load from a file
      .load("hi.properties")     // load from a resource
      .build();

With the file extension of .properties or .yaml/.yml used to determine which parser to use to parse and load the content for the file or resource.

Author: rbygrave

avaje-config/src/main/java/io/avaje/config/Configuration.java

@@ -3,6 +3,7 @@
 import io.avaje.lang.NonNullApi;
 import io.avaje.lang.Nullable;
 
+import java.io.File;
 import java.math.BigDecimal;
 import java.net.URI;
 import java.time.Duration;
@@ -734,6 +735,24 @@ interface Builder {
      */
     Builder putAll(Properties source);
 
+    /**
+     * Load the resource using the extension to determine the parser to use.
+     * <p>
+     * By default, resources with {@code .properties} and {@code .yaml} extensions are supported.
+     *
+     * @param resource The resource with configuration content
+     */
+    Builder load(String resource);
+
+    /**
+     * Load the file using the file extension to determine the parser to use.
+     * <p>
+     * By default, files with {@code .properties} and {@code .yaml} extensions are supported.
+     *
+     * @param file The file with configuration content
+     */
+    Builder load(File file);
+
     /**
      * Optionally set the event runner to use . If not specified a foreground runner will be used.
      */

avaje-config/src/main/java/io/avaje/config/CoreConfigurationBuilder.java

@@ -1,17 +1,24 @@
 package io.avaje.config;
 
-import java.util.*;
+import java.io.File;
+import java.io.FileReader;
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Properties;
+import java.util.ServiceLoader;
 import java.util.stream.Collectors;
 
 import static java.util.Objects.requireNonNull;
 
 final class CoreConfigurationBuilder implements Configuration.Builder {
 
+  private final Parsers parsers = new Parsers();
   private final Map<String, String> sourceMap = new LinkedHashMap<>();
+  private ResourceLoader resourceLoader = initialiseResourceLoader();
   private ModificationEventRunner eventRunner;
   private ConfigurationLog configurationLog;
-  private ResourceLoader resourceLoader;
-
   private boolean includeResourceLoading;
   private InitialLoader initialLoader;
 
@@ -63,6 +70,45 @@ public Configuration.Builder putAll(Properties source) {
     return this;
   }
 
+  @Override
+  public Configuration.Builder load(String resource) {
+    final var configParser = parser(resource);
+    try {
+      try (var inputStream = resourceLoader.getResourceAsStream(resource)) {
+        putAll(configParser.load(inputStream));
+        return this;
+      }
+    } catch (IOException e) {
+      throw new UncheckedIOException(e);
+    }
+  }
+
+  @Override
+  public Configuration.Builder load(File file) {
+    final var configParser = parser(file.getName());
+    try {
+      try (var reader = new FileReader(file)) {
+        putAll(configParser.load(reader));
+        return this;
+      }
+    } catch (IOException e) {
+      throw new UncheckedIOException(e);
+    }
+  }
+
+  private ConfigParser parser(String name) {
+    int pos = name.lastIndexOf('.');
+    if (pos == -1) {
+      throw new IllegalArgumentException("Unable to determine the extension for " + name);
+    }
+    var extension = name.substring(pos + 1);
+    ConfigParser configParser = parsers.get(extension);
+    if (configParser == null) {
+      throw new IllegalArgumentException("No parser registered for extension " + extension);
+    }
+    return configParser;
+  }
+
   @Override
   public Configuration.Builder includeResourceLoading() {
     this.includeResourceLoading = true;
@@ -73,7 +119,6 @@ public Configuration.Builder includeResourceLoading() {
   public Configuration build() {
     final var runner = initRunner();
     final var log = initLog();
-    final var parsers = new Parsers();
     final var sources = ServiceLoader.load(ConfigurationSource.class).stream()
       .map(ServiceLoader.Provider::get)
       .collect(Collectors.toList());
@@ -84,7 +129,7 @@ public Configuration build() {
     var components = new CoreComponents(runner, log, parsers, sources, plugins);
     if (includeResourceLoading) {
       log.preInitialisation();
-      initialLoader = new InitialLoader(components, initResourceLoader());
+      initialLoader = new InitialLoader(components, resourceLoader);
     }
     return new CoreConfiguration(components, initEntries()).postLoad(initialLoader);
   }
@@ -99,13 +144,10 @@ private CoreEntry.CoreMap initEntryMap() {
     return initialLoader == null ? CoreEntry.newMap() : initialLoader.load();
   }
 
-  private ResourceLoader initResourceLoader() {
-    if (resourceLoader == null) {
-      resourceLoader = ServiceLoader.load(ResourceLoader.class)
-        .findFirst()
-        .orElseGet(DefaultResourceLoader::new);
-    }
-    return resourceLoader;
+  private static ResourceLoader initialiseResourceLoader() {
+    return ServiceLoader.load(ResourceLoader.class)
+      .findFirst()
+      .orElseGet(DefaultResourceLoader::new);
   }
 
   private ConfigurationLog initLog() {

avaje-config/src/main/java/io/avaje/config/CoreEntry.java

@@ -70,6 +70,11 @@ private CoreEntry(String value, String source) {
     this.source = source;
   }
 
+  @Override
+  public String toString() {
+    return '{' + value + " source:" + source + '}';
+  }
+
   boolean needsEvaluation() {
     return value != null && value.contains("${");
   }

avaje-config/src/main/java/io/avaje/config/Parsers.java

@@ -53,14 +53,14 @@ Set<Map.Entry<String, ConfigParser>> entrySet() {
    * Return the ConfigParser for the given extension.
    */
   ConfigParser get(String extension) {
-    return parserMap.get(extension);
+    return parserMap.get(extension.toLowerCase());
   }
 
   /**
    * Return true if the extension has a matching parser.
    */
   boolean supportsExtension(String extension) {
-    return parserMap.containsKey(extension);
+    return parserMap.containsKey(extension.toLowerCase());
   }
 
   /**

avaje-config/src/test/java/io/avaje/config/CoreConfigurationTest.java

@@ -4,6 +4,7 @@
 import org.example.MyExternalLoader;
 import org.junit.jupiter.api.Test;
 
+import java.io.File;
 import java.io.StringReader;
 import java.util.*;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -147,17 +148,22 @@ void toEnvKey() {
 
   @Test
   void builder() {
+    var fileSource = new File("./src/test/resources/yaml/minimal.yaml");
     var conf = Configuration.builder()
       .putAll(properties())
       .putAll(Map.of("myExtraMap", "foo", "myExtraMap.b", "bar"))
       .put("myExtraOne", "baz")
+      .load(fileSource)
+      .load("hi.properties")
       .build();
 
     assertEquals(conf.get("a"), "1");
     assertEquals(conf.get("doesNotExist", "something"), "something");
     assertEquals(conf.get("myExtraMap"), "foo");
     assertEquals(conf.get("myExtraMap.b"), "bar");
     assertEquals(conf.get("myExtraOne"), "baz");
+    assertEquals(conf.get("my.name"), "Nom");
+    assertEquals(conf.get("hi.iAmInProps"), "There it is");
 
     String userHome = System.getProperty("user.home");
     assertEquals(conf.get("myHome"), "my/" + userHome + "/home");

avaje-config/src/test/resources/hi.properties

@@ -0,0 +1 @@
+hi.iAmInProps=There it is

avaje-config/src/test/resources/yaml/minimal.yaml

@@ -0,0 +1,2 @@
+my:
+  name: Nom