Support of GenericConverter

This commit makes sure to also include any `GenericConverter` flagged for
inclusion in the conversion service to use to convert configuration keys.

Previously, those were ignored as `Converter` and `GenericConverter` are
two separate interfaces.

Closes gh-4988

spring-boot/src/main/java/org/springframework/boot/context/properties/ConfigurationPropertiesBindingPostProcessor.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -47,6 +47,7 @@ import org.springframework.core.PriorityOrdered;
 import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.converter.Converter;
+import org.springframework.core.convert.converter.GenericConverter;
 import org.springframework.core.convert.support.DefaultConversionService;
 import org.springframework.core.env.ConfigurableEnvironment;
 import org.springframework.core.env.Environment;
@@ -108,6 +109,8 @@ public class ConfigurationPropertiesBindingPostProcessor
 
 	private List<Converter<?, ?>> converters = Collections.emptyList();
 
+	private List<GenericConverter> genericConverters = Collections.emptyList();
+
 	private int order = Ordered.HIGHEST_PRECEDENCE + 1;
 
 	/**
@@ -121,6 +124,17 @@ public class ConfigurationPropertiesBindingPostProcessor
 		this.converters = converters;
 	}
 
+	/**
+	 * A list of custom converters (in addition to the defaults) to use when converting
+	 * properties for binding.
+	 * @param converters the converters to set
+	 */
+	@Autowired(required = false)
+	@ConfigurationPropertiesBinding
+	public void setGenericConverters(List<GenericConverter> converters) {
+		this.genericConverters = converters;
+	}
+
 	/**
 	 * Set the order of the bean.
 	 * @param order the order
@@ -407,6 +421,9 @@ public class ConfigurationPropertiesBindingPostProcessor
 			for (Converter<?, ?> converter : this.converters) {
 				conversionService.addConverter(converter);
 			}
+			for (GenericConverter genericConverter : this.genericConverters) {
+				conversionService.addConverter(genericConverter);
+			}
 			this.defaultConversionService = conversionService;
 		}
 		return this.defaultConversionService;

spring-boot/src/test/java/org/springframework/boot/bind/ConverterBindingTests.java

 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,9 @@
 
 package org.springframework.boot.bind;
 
+import java.util.Collections;
+import java.util.Set;
+
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
@@ -30,7 +33,9 @@ import org.springframework.boot.test.SpringApplicationConfiguration;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
+import org.springframework.core.convert.TypeDescriptor;
 import org.springframework.core.convert.converter.Converter;
+import org.springframework.core.convert.converter.GenericConverter;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
 import static org.hamcrest.Matchers.is;
@@ -40,21 +45,26 @@ import static org.junit.Assert.assertThat;
  * Tests for {@link ConfigurationProperties} binding with custom converters.
  *
  * @author Dave Syer
+ * @author Stephane Nicoll
  */
 @RunWith(SpringJUnit4ClassRunner.class)
 @SpringApplicationConfiguration(TestConfig.class)
-@IntegrationTest("foo=bar")
+@IntegrationTest({"foo=one", "bar=two"})
 public class ConverterBindingTests {
 
 	@Value("${foo:}")
 	private String foo;
 
+	@Value("${bar:}")
+	private String bar;
+
 	@Autowired
 	private Wrapper properties;
 
 	@Test
 	public void overridingOfPropertiesOrderOfAtPropertySources() {
-		assertThat(this.properties.getFoo().getName(), is(this.foo));
+		assertThat(this.properties.getFoo().name, is(this.foo));
+		assertThat(this.properties.getBar().name, is(this.bar));
 	}
 
 	@Configuration
@@ -68,9 +78,22 @@ public class ConverterBindingTests {
 
 				@Override
 				public Foo convert(String source) {
-					Foo foo = new Foo();
-					foo.setName(source);
-					return foo;
+					return new Foo(source);
+				}
+			};
+		}
+
+		@Bean
+		public GenericConverter genericConverter() {
+			return new GenericConverter() {
+				@Override
+				public Set<ConvertiblePair> getConvertibleTypes() {
+					return Collections.singleton(new ConvertiblePair(String.class, Bar.class));
+				}
+
+				@Override
+				public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
+					return new Bar((String) source);
 				}
 			};
 		}
@@ -84,16 +107,20 @@ public class ConverterBindingTests {
 
 	public static class Foo {
 
-		private String name;
+		private final String name;
 
-		public String getName() {
-			return this.name;
+		public Foo(String name) {
+			this.name = name;
 		}
+	}
+
+	public static class Bar {
+
+		private final String name;
 
-		public void setName(String name) {
+		public Bar(String name) {
 			this.name = name;
 		}
-
 	}
 
 	@ConfigurationProperties
@@ -101,6 +128,8 @@ public class ConverterBindingTests {
 
 		private Foo foo;
 
+		private Bar bar;
+
 		public Foo getFoo() {
 			return this.foo;
 		}
@@ -109,6 +138,13 @@ public class ConverterBindingTests {
 			this.foo = foo;
 		}
 
+		public Bar getBar() {
+			return this.bar;
+		}
+
+		public void setBar(Bar bar) {
+			this.bar = bar;
+		}
 	}
 
 }