Add support for RelaxedDataBinder aliases

Update RelaxedDataBinder to support property aliases and change
DataSourceBuilder to use them.

Fixes gh-1384

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/jdbc/DataSourceBuilder.java

@@ -23,7 +23,6 @@ import javax.sql.DataSource;
 
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.MutablePropertyValues;
-import org.springframework.beans.PropertyValues;
 import org.springframework.boot.bind.RelaxedDataBinder;
 import org.springframework.util.ClassUtils;
 
@@ -84,15 +83,8 @@ public class DataSourceBuilder {
 	}
 
 	private void bind(DataSource result) {
-		new RelaxedDataBinder(result).bind(getPropertyValues());
-	}
-
-	private PropertyValues getPropertyValues() {
-		if (getType().getName().contains("Hikari") && this.properties.containsKey("url")) {
-			this.properties.put("jdbcUrl", this.properties.get("url"));
-			this.properties.remove("url");
-		}
-		return new MutablePropertyValues(this.properties);
+		MutablePropertyValues properties = new MutablePropertyValues(this.properties);
+		new RelaxedDataBinder(result).withAlias("url", "jdbcUrl").bind(properties);
 	}
 
 	public DataSourceBuilder type(Class<? extends DataSource> type) {

spring-boot/src/main/java/org/springframework/boot/bind/RelaxedDataBinder.java

@@ -19,6 +19,7 @@ package org.springframework.boot.bind;
 import java.net.InetAddress;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -29,6 +30,8 @@ import org.springframework.beans.InvalidPropertyException;
 import org.springframework.beans.MutablePropertyValues;
 import org.springframework.beans.PropertyValue;
 import org.springframework.core.convert.TypeDescriptor;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
 import org.springframework.util.StringUtils;
 import org.springframework.validation.DataBinder;
 
@@ -47,6 +50,8 @@ public class RelaxedDataBinder extends DataBinder {
 
 	private boolean ignoreNestedProperties;
 
+	private MultiValueMap<String, String> nameAliases = new LinkedMultiValueMap<String, String>();
+
 	/**
 	 * Create a new {@link RelaxedDataBinder} instance.
 	 * @param target the target into which properties are bound
@@ -76,6 +81,27 @@ public class RelaxedDataBinder extends DataBinder {
 		this.ignoreNestedProperties = ignoreNestedProperties;
 	}
 
+	/**
+	 * Set name aliases.
+	 * @param aliases a map of property name to aliases
+	 */
+	public void setNameAliases(Map<String, List<String>> aliases) {
+		this.nameAliases = new LinkedMultiValueMap<String, String>(aliases);
+	}
+
+	/**
+	 * Add aliases to the {@link DataBinder}.
+	 * @param name the property name to alias
+	 * @param alias aliases for the property names
+	 * @return this instance
+	 */
+	public RelaxedDataBinder withAlias(String name, String... alias) {
+		for (String value : alias) {
+			this.nameAliases.add(name, value);
+		}
+		return this;
+	}
+
 	@Override
 	public void initBeanPropertyAccess() {
 		super.initBeanPropertyAccess();
@@ -262,19 +288,33 @@ public class RelaxedDataBinder extends DataBinder {
 
 	private String getActualPropertyName(BeanWrapper target, String prefix, String name) {
 		prefix = StringUtils.hasText(prefix) ? prefix + "." : "";
-		for (String candidate : new RelaxedNames(name)) {
-			try {
-				if (target.getPropertyType(prefix + candidate) != null) {
-					return candidate;
+		Iterable<String> names = getNameAndAliases(name);
+		for (String nameOrAlias : names) {
+			for (String candidate : new RelaxedNames(nameOrAlias)) {
+				try {
+					if (target.getPropertyType(prefix + candidate) != null) {
+						return candidate;
+					}
+				}
+				catch (InvalidPropertyException ex) {
+					// swallow and continue
 				}
-			}
-			catch (InvalidPropertyException ex) {
-				// swallow and continue
 			}
 		}
 		return name;
 	}
 
+	private Iterable<String> getNameAndAliases(String name) {
+		List<String> aliases = this.nameAliases.get(name);
+		if (aliases == null) {
+			return Collections.singleton(name);
+		}
+		List<String> nameAndAliases = new ArrayList<String>(aliases.size() + 1);
+		nameAndAliases.add(name);
+		nameAndAliases.addAll(aliases);
+		return nameAndAliases;
+	}
+
 	private static Object wrapTarget(Object target) {
 		if (target instanceof Map) {
 			@SuppressWarnings("unchecked")

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

@@ -53,6 +53,7 @@ import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
 
 import static java.lang.annotation.RetentionPolicy.RUNTIME;
 import static org.hamcrest.Matchers.equalTo;
+import static org.hamcrest.Matchers.nullValue;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
@@ -444,6 +445,28 @@ public class RelaxedDataBinderTests {
 		doTestBindCaseInsensitiveEnums(target);
 	}
 
+	@Test
+	public void testBindWithoutAlais() throws Exception {
+		VanillaTarget target = new VanillaTarget();
+		MutablePropertyValues properties = new MutablePropertyValues();
+		properties.add("flub", "a");
+		properties.add("foo", "b");
+		new RelaxedDataBinder(target).bind(properties);
+		assertThat(target.getFooBaz(), nullValue());
+		assertThat(target.getFoo(), equalTo("b"));
+	}
+
+	@Test
+	public void testBindWithAlias() throws Exception {
+		VanillaTarget target = new VanillaTarget();
+		MutablePropertyValues properties = new MutablePropertyValues();
+		properties.add("flub", "a");
+		properties.add("foo", "b");
+		new RelaxedDataBinder(target).withAlias("flub", "fooBaz").bind(properties);
+		assertThat(target.getFooBaz(), equalTo("a"));
+		assertThat(target.getFoo(), equalTo("b"));
+	}
+
 	private void doTestBindCaseInsensitiveEnums(VanillaTarget target) throws Exception {
 		BindingResult result = bind(target, "bingo: THIS");
 		assertThat(result.getErrorCount(), equalTo(0));