Merge pull request #3252 from mawen12/optimize-mapper-builder

optimize mapper builder

Author: hazendaz

src/main/java/org/apache/ibatis/builder/xml/XMLMapperBuilder.java

@@ -239,7 +239,7 @@ private ResultMap resultMapElement(XNode resultMapNode, List<ResultMapping> addi
         resultMappings.add(buildResultMappingFromContext(resultChild, typeClass, flags));
       }
     }
-    String id = resultMapNode.getStringAttribute("id", resultMapNode.getValueBasedIdentifier());
+    String id = resultMapNode.getStringAttribute("id", resultMapNode::getValueBasedIdentifier);
     String extend = resultMapNode.getStringAttribute("extends");
     Boolean autoMapping = resultMapNode.getBooleanAttribute("autoMapping");
     ResultMapResolver resultMapResolver = new ResultMapResolver(builderAssistant, id, typeClass, extend, discriminator,
@@ -289,8 +289,7 @@ private Discriminator processDiscriminatorElement(XNode context, Class<?> result
     Map<String, String> discriminatorMap = new HashMap<>();
     for (XNode caseChild : context.getChildren()) {
       String value = caseChild.getStringAttribute("value");
-      String resultMap = caseChild.getStringAttribute("resultMap",
-          processNestedResultMappings(caseChild, resultMappings, resultType));
+      String resultMap = caseChild.getStringAttribute("resultMap", () -> processNestedResultMappings(caseChild, resultMappings, resultType));
       discriminatorMap.put(value, resultMap);
     }
     return builderAssistant.buildDiscriminator(resultType, column, javaTypeClass, jdbcTypeEnum, typeHandlerClass,

src/test/java/org/apache/ibatis/type/TypeAliasRegistryTest.java

@@ -15,6 +15,7 @@
  */
 package org.apache.ibatis.type;
 
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNull;
 import static org.junit.jupiter.api.Assertions.assertThrows;
@@ -75,4 +76,21 @@ void shouldFetchCharType() {
     assertEquals(char[].class, typeAliasRegistry.resolveAlias("_char[]"));
   }
 
+  @Test
+  void shouldNotBeAbleToRegisterAliasWithEmptyString() {
+    TypeAliasRegistry typeAliasRegistry = new TypeAliasRegistry();
+
+    assertThatThrownBy(() -> typeAliasRegistry.registerAlias("foo", ""))
+      .isInstanceOf(TypeException.class)
+      .hasMessageContaining("Error registering type alias foo for");
+  }
+
+  @Test
+  void shouldNotBeAbleToResolveNotExistsAlias() {
+    TypeAliasRegistry typeAliasRegistry = new TypeAliasRegistry();
+
+    assertThatThrownBy(() -> typeAliasRegistry.resolveAlias("abc"))
+      .isInstanceOf(TypeException.class)
+      .hasMessageContaining("Could not resolve type alias 'abc'.  Cause: java.lang.ClassNotFoundException: Cannot find class: abc");
+  }
 }