fixes #1381 When there is no 'resultType' nor 'resultMap' specified for <association />, use the property's java type.

Author: harawata

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

@@ -43,6 +43,7 @@
 import org.apache.ibatis.mapping.ResultMapping;
 import org.apache.ibatis.parsing.XNode;
 import org.apache.ibatis.parsing.XPathParser;
+import org.apache.ibatis.reflection.MetaClass;
 import org.apache.ibatis.session.Configuration;
 import org.apache.ibatis.type.JdbcType;
 import org.apache.ibatis.type.TypeHandler;
@@ -249,10 +250,10 @@ private void resultMapElements(List<XNode> list) throws Exception {
   }
 
   private ResultMap resultMapElement(XNode resultMapNode) throws Exception {
-    return resultMapElement(resultMapNode, Collections.<ResultMapping> emptyList());
+    return resultMapElement(resultMapNode, Collections.<ResultMapping> emptyList(), null);
   }
 
-  private ResultMap resultMapElement(XNode resultMapNode, List<ResultMapping> additionalResultMappings) throws Exception {
+  private ResultMap resultMapElement(XNode resultMapNode, List<ResultMapping> additionalResultMappings, Class<?> enclosingType) throws Exception {
     ErrorContext.instance().activity("processing " + resultMapNode.getValueBasedIdentifier());
     String id = resultMapNode.getStringAttribute("id",
         resultMapNode.getValueBasedIdentifier());
@@ -263,6 +264,9 @@ private ResultMap resultMapElement(XNode resultMapNode, List<ResultMapping> addi
     String extend = resultMapNode.getStringAttribute("extends");
     Boolean autoMapping = resultMapNode.getBooleanAttribute("autoMapping");
     Class<?> typeClass = resolveClass(type);
+    if (typeClass == null) {
+      typeClass = inheritEnclosingType(resultMapNode, enclosingType);
+    }
     Discriminator discriminator = null;
     List<ResultMapping> resultMappings = new ArrayList<>();
     resultMappings.addAll(additionalResultMappings);
@@ -289,6 +293,17 @@ private ResultMap resultMapElement(XNode resultMapNode, List<ResultMapping> addi
     }
   }
 
+  protected Class<?> inheritEnclosingType(XNode resultMapNode, Class<?> enclosingType) {
+    if ("association".equals(resultMapNode.getName()) && resultMapNode.getStringAttribute("resultMap") == null) {
+      String property = resultMapNode.getStringAttribute("property");
+      if (property != null && enclosingType != null) {
+        MetaClass metaResultType = MetaClass.forClass(enclosingType, configuration.getReflectorFactory());
+        return metaResultType.getSetterType(property);
+      }
+    }
+    return null;
+  }
+
   private void processConstructorElement(XNode resultChild, Class<?> resultType, List<ResultMapping> resultMappings) throws Exception {
     List<XNode> argChildren = resultChild.getChildren();
     for (XNode argChild : argChildren) {
@@ -313,7 +328,7 @@ 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));
+      String resultMap = caseChild.getStringAttribute("resultMap", processNestedResultMappings(caseChild, resultMappings, resultType));
       discriminatorMap.put(value, resultMap);
     }
     return builderAssistant.buildDiscriminator(resultType, column, javaTypeClass, jdbcTypeEnum, typeHandlerClass, discriminatorMap);
@@ -369,7 +384,7 @@ private ResultMapping buildResultMappingFromContext(XNode context, Class<?> resu
     String jdbcType = context.getStringAttribute("jdbcType");
     String nestedSelect = context.getStringAttribute("select");
     String nestedResultMap = context.getStringAttribute("resultMap",
-        processNestedResultMappings(context, Collections.<ResultMapping> emptyList()));
+        processNestedResultMappings(context, Collections.<ResultMapping> emptyList(), resultType));
     String notNullColumn = context.getStringAttribute("notNullColumn");
     String columnPrefix = context.getStringAttribute("columnPrefix");
     String typeHandler = context.getStringAttribute("typeHandler");
@@ -382,13 +397,13 @@ private ResultMapping buildResultMappingFromContext(XNode context, Class<?> resu
     JdbcType jdbcTypeEnum = resolveJdbcType(jdbcType);
     return builderAssistant.buildResultMapping(resultType, property, column, javaTypeClass, jdbcTypeEnum, nestedSelect, nestedResultMap, notNullColumn, columnPrefix, typeHandlerClass, flags, resultSet, foreignColumn, lazy);
   }
-  
-  private String processNestedResultMappings(XNode context, List<ResultMapping> resultMappings) throws Exception {
+
+  private String processNestedResultMappings(XNode context, List<ResultMapping> resultMappings, Class<?> enclosingType) throws Exception {
     if ("association".equals(context.getName())
         || "collection".equals(context.getName())
         || "case".equals(context.getName())) {
       if (context.getStringAttribute("select") == null) {
-        ResultMap resultMap = resultMapElement(context, resultMappings);
+        ResultMap resultMap = resultMapElement(context, resultMappings, enclosingType);
         return resultMap.getId();
       }
     }

src/test/java/org/apache/ibatis/submitted/associationtest/Mapper.java

@@ -1,5 +1,5 @@
 /**
- *    Copyright 2009-2015 the original author or authors.
+ *    Copyright 2009-2018 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.

src/test/java/org/apache/ibatis/submitted/associationtest/Mapper.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <!--
 
-       Copyright 2009-2016 the original author or authors.
+       Copyright 2009-2018 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.