Add JsonConfiguration support to bungeecord-config

Thanks @FelixKlauke for the idea in #2364, however this implementation was designed to mirror as much of the existing YamlConfiguration as possible and have Gson as an optional depend.

api/pom.xml

@@ -49,5 +49,11 @@
             <version>${netty.version}</version>
             <scope>compile</scope>
         </dependency>
+        <dependency>
+            <groupId>org.yaml</groupId>
+            <artifactId>snakeyaml</artifactId>
+            <version>1.25</version>
+            <scope>compile</scope>
+        </dependency>
     </dependencies>
 </project>

config/pom.xml

@@ -19,11 +19,19 @@
     <description>Generic java configuration API intended for use with BungeeCord</description>
 
     <dependencies>
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>
+            <version>2.8.0</version>
+            <scope>compile</scope>
+            <optional>true</optional>
+        </dependency>
         <dependency>
             <groupId>org.yaml</groupId>
             <artifactId>snakeyaml</artifactId>
             <version>1.25</version>
             <scope>compile</scope>
+            <optional>true</optional>
         </dependency>
     </dependencies>
 </project>

config/src/main/java/net/md_5/bungee/config/ConfigurationProvider.java

@@ -14,8 +14,22 @@ public abstract class ConfigurationProvider
     private static final Map<Class<? extends ConfigurationProvider>, ConfigurationProvider> providers = new HashMap<>();
 
     static
+    {
+        try
         {
             providers.put( YamlConfiguration.class, new YamlConfiguration() );
+        } catch ( NoClassDefFoundError ex )
+        {
+            // Ignore, no SnakeYAML
+        }
+
+        try
+        {
+            providers.put( JsonConfiguration.class, new JsonConfiguration() );
+        } catch ( NoClassDefFoundError ex )
+        {
+            // Ignore, no Gson
+        }
     }
 
     public static ConfigurationProvider getProvider(Class<? extends ConfigurationProvider> provider)

config/src/main/java/net/md_5/bungee/config/JsonConfiguration.java

@@ -0,0 +1,114 @@
+package net.md_5.bungee.config;
+
+import com.google.common.base.Charsets;
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonSerializationContext;
+import com.google.gson.JsonSerializer;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.OutputStreamWriter;
+import java.io.Reader;
+import java.io.Writer;
+import java.lang.reflect.Type;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import lombok.AccessLevel;
+import lombok.NoArgsConstructor;
+
+@NoArgsConstructor(access = AccessLevel.PACKAGE)
+public class JsonConfiguration extends ConfigurationProvider
+{
+
+    private final Gson json = new GsonBuilder().serializeNulls().setPrettyPrinting().registerTypeAdapter( Configuration.class, new JsonSerializer<Configuration>()
+    {
+        @Override
+        public JsonElement serialize(Configuration src, Type typeOfSrc, JsonSerializationContext context)
+        {
+            return context.serialize( ( (Configuration) src ).self );
+        }
+    } ).create();
+
+    @Override
+    public void save(Configuration config, File file) throws IOException
+    {
+        try ( Writer writer = new OutputStreamWriter( new FileOutputStream( file ), Charsets.UTF_8 ) )
+        {
+            save( config, writer );
+        }
+    }
+
+    @Override
+    public void save(Configuration config, Writer writer)
+    {
+        json.toJson( config.self, writer );
+    }
+
+    @Override
+    public Configuration load(File file) throws IOException
+    {
+        return load( file, null );
+    }
+
+    @Override
+    public Configuration load(File file, Configuration defaults) throws IOException
+    {
+        try ( FileInputStream is = new FileInputStream( file ) )
+        {
+            return load( is, defaults );
+        }
+    }
+
+    @Override
+    public Configuration load(Reader reader)
+    {
+        return load( reader, null );
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public Configuration load(Reader reader, Configuration defaults)
+    {
+        Map<String, Object> map = json.fromJson( reader, LinkedHashMap.class );
+        if ( map == null )
+        {
+            map = new LinkedHashMap<>();
+        }
+        return new Configuration( map, defaults );
+    }
+
+    @Override
+    public Configuration load(InputStream is)
+    {
+        return load( is, null );
+    }
+
+    @Override
+    public Configuration load(InputStream is, Configuration defaults)
+    {
+        return load( new InputStreamReader( is, Charsets.UTF_8 ), defaults );
+    }
+
+    @Override
+    public Configuration load(String string)
+    {
+        return load( string, null );
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public Configuration load(String string, Configuration defaults)
+    {
+        Map<String, Object> map = json.fromJson( string, LinkedHashMap.class );
+        if ( map == null )
+        {
+            map = new LinkedHashMap<>();
+        }
+        return new Configuration( map, defaults );
+    }
+}

config/src/test/java/net/md_5/bungee/config/CompoundConfigurationTest.java

@@ -0,0 +1,229 @@
+package net.md_5.bungee.config;
+
+import java.io.StringReader;
+import java.io.StringWriter;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import lombok.RequiredArgsConstructor;
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameters;
+
+@RequiredArgsConstructor
+@RunWith(Parameterized.class)
+public class CompoundConfigurationTest
+{
+
+    @Parameters(name = "{0}")
+    public static Iterable<Object[]> data()
+    {
+        // CHECKSTYLE:OFF
+        return Arrays.asList( new Object[][]
+        {
+            {
+                // provider
+                YamlConfiguration.class,
+                // testDocument
+                ""
+                + "receipt:     Oz-Ware Purchase Invoice\n"
+                + "date:        2012-08-06\n"
+                + "customer:\n"
+                + "    given:   Dorothy\n"
+                + "    family:  Gale\n"
+                + "\n"
+                + "items:\n"
+                + "    - part_no:   A4786\n"
+                + "      descrip:   Water Bucket (Filled)\n"
+                + "      price:     1.47\n"
+                + "      quantity:  4\n"
+                + "\n"
+                + "    - part_no:   E1628\n"
+                + "      descrip:   High Heeled \"Ruby\" Slippers\n"
+                + "      size:      8\n"
+                + "      price:     100.27\n"
+                + "      quantity:  1\n"
+                + "\n"
+                + "bill-to:  &id001\n"
+                + "    street: |\n"
+                + "            123 Tornado Alley\n"
+                + "            Suite 16\n"
+                + "    city:   East Centerville\n"
+                + "    state:  KS\n"
+                + "\n"
+                + "ship-to:  *id001\n"
+                + "\n"
+                + "specialDelivery:  >\n"
+                + "    Follow the Yellow Brick\n"
+                + "    Road to the Emerald City.\n"
+                + "    Pay no attention to the\n"
+                + "    man behind the curtain.",
+                // numberTest
+                ""
+                + "someKey:\n"
+                + "    1: 1\n"
+                + "    2: 2\n"
+                + "    3: 3\n"
+                + "    4: 4",
+                // nullTest
+                ""
+                + "null:\n"
+                + "    null: object\n"
+                + "    object: null\n"
+            },
+            {
+                // provider
+                JsonConfiguration.class,
+                // testDocument
+                ""
+                + "{\n"
+                + "  \"customer\": {\n"
+                + "    \"given\": \"Dorothy\", \n"
+                + "    \"family\": \"Gale\"\n"
+                + "  }, \n"
+                + "  \"ship-to\": {\n"
+                + "    \"city\": \"East Centerville\", \n"
+                + "    \"state\": \"KS\", \n"
+                + "    \"street\": \"123 Tornado Alley\\nSuite 16\\n\"\n"
+                + "  }, \n"
+                + "  \"bill-to\": {\n"
+                + "    \"city\": \"East Centerville\", \n"
+                + "    \"state\": \"KS\", \n"
+                + "    \"street\": \"123 Tornado Alley\\nSuite 16\\n\"\n"
+                + "  }, \n"
+                + "  \"date\": \"2012-08-06\", \n"
+                + "  \"items\": [\n"
+                + "    {\n"
+                + "      \"part_no\": \"A4786\", \n"
+                + "      \"price\": 1.47, \n"
+                + "      \"descrip\": \"Water Bucket (Filled)\", \n"
+                + "      \"quantity\": 4\n"
+                + "    }, \n"
+                + "    {\n"
+                + "      \"part_no\": \"E1628\", \n"
+                + "      \"descrip\": \"High Heeled \\\"Ruby\\\" Slippers\", \n"
+                + "      \"price\": 100.27, \n"
+                + "      \"quantity\": 1, \n"
+                + "      \"size\": 8\n"
+                + "    }\n"
+                + "  ], \n"
+                + "  \"receipt\": \"Oz-Ware Purchase Invoice\", \n"
+                + "  \"specialDelivery\": \"Follow the Yellow Brick Road to the Emerald City. Pay no attention to the man behind the curtain.\"\n"
+                + "}",
+                // numberTest
+                ""
+                + "{\n"
+                + "  \"someKey\": {\n"
+                + "    \"1\": 1, \n"
+                + "    \"2\": 2, \n"
+                + "    \"3\": 3, \n"
+                + "    \"4\": 4\n"
+                + "  }\n"
+                + "}",
+                // nullTest
+                ""
+                + "{\n"
+                + "  \"null\": {\n"
+                + "    \"null\": \"object\", \n"
+                + "    \"object\": null\n"
+                + "  }\n"
+                + "}"
+            }
+        } );
+        // CHECKSTYLE:ON
+    }
+    //
+    private final Class<? extends ConfigurationProvider> provider;
+    private final String testDocument;
+    private final String numberTest;
+    private final String nullTest;
+
+    @Test
+    public void testConfig() throws Exception
+    {
+        Configuration conf = ConfigurationProvider.getProvider( provider ).load( testDocument );
+        testSection( conf );
+
+        StringWriter sw = new StringWriter();
+        ConfigurationProvider.getProvider( provider ).save( conf, sw );
+
+        // Check nulls were saved, see #1094
+        Assert.assertFalse( "Config contains null", sw.toString().contains( "null" ) );
+
+        conf = ConfigurationProvider.getProvider( provider ).load( new StringReader( sw.toString() ) );
+        conf.set( "receipt", "Oz-Ware Purchase Invoice" ); // Add it back
+        testSection( conf );
+    }
+
+    private void testSection(Configuration conf)
+    {
+        Assert.assertEquals( "receipt", "Oz-Ware Purchase Invoice", conf.getString( "receipt" ) );
+        // Assert.assertEquals( "date", "2012-08-06", conf.get( "date" ).toString() );
+
+        Configuration customer = conf.getSection( "customer" );
+        Assert.assertEquals( "customer.given", "Dorothy", customer.getString( "given" ) );
+        Assert.assertEquals( "customer.given", "Dorothy", conf.getString( "customer.given" ) );
+
+        List items = conf.getList( "items" );
+        Map item = (Map) items.get( 0 );
+        Assert.assertEquals( "items[0].part_no", "A4786", item.get( "part_no" ) );
+
+        conf.set( "receipt", null );
+        Assert.assertEquals( null, conf.get( "receipt" ) );
+        Assert.assertEquals( "foo", conf.get( "receipt", "foo" ) );
+
+        Configuration newSection = conf.getSection( "new.section" );
+        newSection.set( "value", "foo" );
+        Assert.assertEquals( "foo", conf.get( "new.section.value" ) );
+
+        conf.set( "other.new.section", "bar" );
+        Assert.assertEquals( "bar", conf.get( "other.new.section" ) );
+
+        Assert.assertTrue( conf.contains( "customer.given" ) );
+        Assert.assertTrue( customer.contains( "given" ) );
+
+        Assert.assertFalse( conf.contains( "customer.foo" ) );
+        Assert.assertFalse( customer.contains( "foo" ) );
+    }
+
+    @Test
+    public void testNumberedKeys()
+    {
+        Configuration conf = ConfigurationProvider.getProvider( provider ).load( numberTest );
+
+        Configuration section = conf.getSection( "someKey" );
+        for ( String key : section.getKeys() )
+        {
+            // empty
+        }
+    }
+
+    @Test
+    public void testNull()
+    {
+        Configuration conf = ConfigurationProvider.getProvider( provider ).load( nullTest );
+
+        Assert.assertEquals( "object", conf.get( "null.null" ) );
+        Assert.assertEquals( "object", conf.getSection( "null" ).get( "null" ) );
+
+        Assert.assertEquals( null, conf.get( "null.object" ) );
+        Assert.assertEquals( "", conf.getString( "null.object" ) );
+    }
+
+    @Test
+    public void testMapAddition()
+    {
+        Configuration conf = ConfigurationProvider.getProvider( provider ).load( testDocument );
+
+        conf.set( "addition", Collections.singletonMap( "foo", "bar" ) );
+
+        // Order matters
+        Assert.assertEquals( "bar", conf.getSection( "addition" ).getString( "foo" ) );
+        Assert.assertEquals( "bar", conf.getString( "addition.foo" ) );
+
+        Assert.assertTrue( conf.get( "addition" ) instanceof Configuration );
+    }
+}

config/src/test/java/net/md_5/bungee/config/YamlConfigurationTest.java

@@ -1,143 +0,0 @@
-package net.md_5.bungee.config;
-
-import java.io.StringReader;
-import java.io.StringWriter;
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import org.junit.Assert;
-import org.junit.Test;
-
-public class YamlConfigurationTest
-{
-
-    private static final String TEST_DOCUMENT = ""
-            + "receipt:     Oz-Ware Purchase Invoice\n"
-            + "date:        2012-08-06\n"
-            + "customer:\n"
-            + "    given:   Dorothy\n"
-            + "    family:  Gale\n"
-            + "\n"
-            + "items:\n"
-            + "    - part_no:   A4786\n"
-            + "      descrip:   Water Bucket (Filled)\n"
-            + "      price:     1.47\n"
-            + "      quantity:  4\n"
-            + "\n"
-            + "    - part_no:   E1628\n"
-            + "      descrip:   High Heeled \"Ruby\" Slippers\n"
-            + "      size:      8\n"
-            + "      price:     100.27\n"
-            + "      quantity:  1\n"
-            + "\n"
-            + "bill-to:  &id001\n"
-            + "    street: |\n"
-            + "            123 Tornado Alley\n"
-            + "            Suite 16\n"
-            + "    city:   East Centerville\n"
-            + "    state:  KS\n"
-            + "\n"
-            + "ship-to:  *id001\n"
-            + "\n"
-            + "specialDelivery:  >\n"
-            + "    Follow the Yellow Brick\n"
-            + "    Road to the Emerald City.\n"
-            + "    Pay no attention to the\n"
-            + "    man behind the curtain.";
-    private static final String NUMBER_TEST = ""
-            + "someKey:\n"
-            + "    1: 1\n"
-            + "    2: 2\n"
-            + "    3: 3\n"
-            + "    4: 4";
-    private static final String NULL_TEST = ""
-            + "null:\n"
-            + "    null: object\n"
-            + "    object: null\n";
-
-    @Test
-    public void testConfig() throws Exception
-    {
-        Configuration conf = ConfigurationProvider.getProvider( YamlConfiguration.class ).load( TEST_DOCUMENT );
-        testSection( conf );
-
-        StringWriter sw = new StringWriter();
-        ConfigurationProvider.getProvider( YamlConfiguration.class ).save( conf, sw );
-
-        // Check nulls were saved, see #1094
-        Assert.assertFalse( "Config contains null", sw.toString().contains( "null" ) );
-
-        conf = ConfigurationProvider.getProvider( YamlConfiguration.class ).load( new StringReader( sw.toString() ) );
-        conf.set( "receipt", "Oz-Ware Purchase Invoice" ); // Add it back
-        testSection( conf );
-    }
-
-    private void testSection(Configuration conf)
-    {
-        Assert.assertEquals( "receipt", "Oz-Ware Purchase Invoice", conf.getString( "receipt" ) );
-        // Assert.assertEquals( "date", "2012-08-06", conf.get( "date" ).toString() );
-
-        Configuration customer = conf.getSection( "customer" );
-        Assert.assertEquals( "customer.given", "Dorothy", customer.getString( "given" ) );
-        Assert.assertEquals( "customer.given", "Dorothy", conf.getString( "customer.given" ) );
-
-        List items = conf.getList( "items" );
-        Map item = (Map) items.get( 0 );
-        Assert.assertEquals( "items[0].part_no", "A4786", item.get( "part_no" ) );
-
-        conf.set( "receipt", null );
-        Assert.assertEquals( null, conf.get( "receipt" ) );
-        Assert.assertEquals( "foo", conf.get( "receipt", "foo" ) );
-
-        Configuration newSection = conf.getSection( "new.section" );
-        newSection.set( "value", "foo" );
-        Assert.assertEquals( "foo", conf.get( "new.section.value" ) );
-
-        conf.set( "other.new.section", "bar" );
-        Assert.assertEquals( "bar", conf.get( "other.new.section" ) );
-
-        Assert.assertTrue( conf.contains( "customer.given" ) );
-        Assert.assertTrue( customer.contains( "given" ) );
-
-        Assert.assertFalse( conf.contains( "customer.foo" ) );
-        Assert.assertFalse( customer.contains( "foo" ) );
-    }
-
-    @Test
-    public void testNumberedKeys()
-    {
-        Configuration conf = ConfigurationProvider.getProvider( YamlConfiguration.class ).load( NUMBER_TEST );
-
-        Configuration section = conf.getSection( "someKey" );
-        for ( String key : section.getKeys() )
-        {
-            // empty
-        }
-    }
-
-    @Test
-    public void testNull()
-    {
-        Configuration conf = ConfigurationProvider.getProvider( YamlConfiguration.class ).load( NULL_TEST );
-
-        Assert.assertEquals( "object", conf.get( "null.null" ) );
-        Assert.assertEquals( "object", conf.getSection( "null" ).get( "null" ) );
-
-        Assert.assertEquals( null, conf.get( "null.object" ) );
-        Assert.assertEquals( "", conf.getString( "null.object" ) );
-    }
-
-    @Test
-    public void testMapAddition()
-    {
-        Configuration conf = ConfigurationProvider.getProvider( YamlConfiguration.class ).load( TEST_DOCUMENT );
-
-        conf.set( "addition", Collections.singletonMap( "foo", "bar" ) );
-
-        // Order matters
-        Assert.assertEquals( "bar", conf.getSection( "addition" ).getString( "foo" ) );
-        Assert.assertEquals( "bar", conf.getString( "addition.foo" ) );
-
-        Assert.assertTrue( conf.get( "addition" ) instanceof Configuration );
-    }
-}