DATAJDBC-542 - Fixes access to Identifier parts by String.

Enabled access to identifier parts by String arguments in order to make usage with MyBatis feasable.
Properly pass identifier information to MyBatis for insert statements.

Original pull request: #218.

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/mybatis/MyBatisContext.java

@@ -104,7 +104,12 @@ public class MyBatisContext {
 	 */
 	@Nullable
 	public Object get(String key) {
-		return additionalValues.get(key);
-	}
 
+		Object value = null;
+		if (identifier != null) {
+			value = identifier.toMap().get(key);
+		}
+
+		return value == null ? additionalValues.get(key) : value;
+	}
 }

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/mybatis/MyBatisDataAccessStrategy.java

@@ -153,8 +153,7 @@ public class MyBatisDataAccessStrategy implements DataAccessStrategy {
 	@Override
 	public <T> Object insert(T instance, Class<T> domainType, Identifier identifier) {
 
-		MyBatisContext myBatisContext = new MyBatisContext(null, instance, domainType,
-				convertToParameterMap(identifier.toMap()));
+		MyBatisContext myBatisContext = new MyBatisContext(identifier, instance, domainType);
 		sqlSession().insert(namespace(domainType) + ".insert", myBatisContext);
 
 		return myBatisContext.getId();

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/core/convert/IdentifierUnitTests.java

@@ -22,8 +22,10 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import org.assertj.core.api.Assertions;
+import org.assertj.core.api.SoftAssertions;
 import org.junit.Test;
 import org.springframework.data.relational.core.sql.IdentifierProcessing;
 import org.springframework.data.relational.core.sql.SqlIdentifier;
@@ -111,4 +113,23 @@ public class IdentifierUnitTests {
 		assertThat(one).isEqualTo(two);
 		assertThat(one).isNotEqualTo(three);
 	}
+
+	@Test // DATAJDBC-542
+	public void identifierPartsCanBeAccessedByString() {
+
+		Map<SqlIdentifier, Object> idParts = new HashMap<>();
+		idParts.put(unquoted("aName"), "one");
+		idParts.put(quoted("Other"), "two");
+
+		Identifier id = Identifier.from(idParts);
+
+		Map<SqlIdentifier, Object> map = id.toMap();
+
+		SoftAssertions.assertSoftly(softly -> {
+			softly.assertThat(map.get("aName")).describedAs("aName").isEqualTo("one");
+			softly.assertThat(map.get("Other")).describedAs("Other").isEqualTo("two");
+			softly.assertThat(map.get("other")).describedAs("other").isNull();
+			softly.assertThat(map.get("OTHER")).describedAs("OTHER").isNull();
+		});
+	}
 }

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/mybatis/MyBatisContextUnitTests.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2020 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jdbc.mybatis;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.assertj.core.api.SoftAssertions;
+import org.junit.Test;
+import org.springframework.data.jdbc.core.convert.Identifier;
+import org.springframework.data.relational.core.sql.SqlIdentifier;
+
+public class MyBatisContextUnitTests {
+
+	@Test // DATAJDBC-542
+	public void testGetReturnsValuesFromIdentifier() {
+
+		Map<SqlIdentifier, Object> map = new HashMap<>();
+		map.put(SqlIdentifier.quoted("one"), "oneValue");
+		map.put(SqlIdentifier.unquoted("two"), "twoValue");
+		map.put(SqlIdentifier.quoted("Three"), "threeValue");
+		map.put(SqlIdentifier.unquoted("Four"), "fourValue");
+
+		MyBatisContext context = new MyBatisContext(Identifier.from(map), null, null);
+
+		SoftAssertions.assertSoftly(softly -> {
+
+			softly.assertThat(context.get("one")).isEqualTo("oneValue");
+			softly.assertThat(context.get("two")).isEqualTo("twoValue");
+			softly.assertThat(context.get("Three")).isEqualTo("threeValue");
+			softly.assertThat(context.get("Four")).isEqualTo("fourValue");
+			softly.assertThat(context.get("four")).isNull();
+			softly.assertThat(context.get("five")).isNull();
+		});
+	}
+
+}

spring-data-relational/src/main/java/org/springframework/data/jdbc/core/convert/Identifier.java

@@ -27,6 +27,7 @@ import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 
 import org.springframework.data.relational.core.sql.SqlIdentifier;
 import org.springframework.util.Assert;
@@ -144,7 +145,7 @@ public final class Identifier {
 	 */
 	public Map<SqlIdentifier, Object> toMap() {
 
-		Map<SqlIdentifier, Object> result = new LinkedHashMap<>();
+		Map<SqlIdentifier, Object> result = new StringKeyedLinkedHashMap<>();
 		forEach((name, value, type) -> result.put(name, value));
 		return result;
 	}
@@ -212,4 +213,21 @@ public final class Identifier {
 		 */
 		void accept(SqlIdentifier name, Object value, Class<?> targetType);
 	}
+
+	private static class StringKeyedLinkedHashMap<V> extends LinkedHashMap<SqlIdentifier,V> {
+
+		@Override
+		public V get(Object key) {
+
+			if (key instanceof String) {
+
+				for (SqlIdentifier sqlIdentifier : keySet()) {
+					if (sqlIdentifier.getReference().equals(key)) {
+						return super.get(sqlIdentifier);
+					}
+				}
+			}
+			return super.get(key);
+		}
+	}
 }