Fixes mybatis#307. Create an instance when all the values for an obje…

…ct are

null but there is at least one defered value.

src/main/java/org/apache/ibatis/executor/resultset/DefaultResultSetHandler.java

@@ -61,7 +61,7 @@
  */
 public class DefaultResultSetHandler implements ResultSetHandler {
 
-  private static final Object NO_VALUE = new Object();
+  private static final Object DEFERED = new Object();
 
   private final Executor executor;
   private final Configuration configuration;
@@ -368,18 +368,24 @@ private boolean applyPropertyMappings(ResultSetWrapper rsw, ResultMap resultMap,
     boolean foundValues = false;
     final List<ResultMapping> propertyMappings = resultMap.getPropertyResultMappings();
     for (ResultMapping propertyMapping : propertyMappings) {
-      final String column = prependPrefix(propertyMapping.getColumn(), columnPrefix);
+      String column = prependPrefix(propertyMapping.getColumn(), columnPrefix);
+      if (propertyMapping.getNestedResultMapId() != null) {
+        // the user added a column attribute to a nested result map, ignore it
+        column = null;
+      }      
       if (propertyMapping.isCompositeResult() 
           || (column != null && mappedColumnNames.contains(column.toUpperCase(Locale.ENGLISH))) 
           || propertyMapping.getResultSet() != null) {
         Object value = getPropertyMappingValue(rsw.getResultSet(), metaObject, propertyMapping, lazyLoader, columnPrefix);
         // issue #541 make property optional
         final String property = propertyMapping.getProperty();
         // issue #377, call setter on nulls
-        if (value != NO_VALUE && property != null && (value != null || configuration.isCallSettersOnNulls())) {
-          if (value != null || !metaObject.getSetterType(property).isPrimitive()) {
-            metaObject.setValue(property, value);
-          }
+        if (value != DEFERED
+            && property != null
+            && (value != null || (configuration.isCallSettersOnNulls() && !metaObject.getSetterType(property).isPrimitive()))) {
+          metaObject.setValue(property, value);
+        }
+        if (value != null || value == DEFERED) {
           foundValues = true;
         }
       }
@@ -392,11 +398,8 @@ private Object getPropertyMappingValue(ResultSet rs, MetaObject metaResultObject
     if (propertyMapping.getNestedQueryId() != null) {
       return getNestedQueryMappingValue(rs, metaResultObject, propertyMapping, lazyLoader, columnPrefix);
     } else if (propertyMapping.getResultSet() != null) {
-      addPendingChildRelation(rs, metaResultObject, propertyMapping);
-      return NO_VALUE;
-    } else if (propertyMapping.getNestedResultMapId() != null) {
-      // the user added a column attribute to a nested result map, ignore it
-      return NO_VALUE;
+      addPendingChildRelation(rs, metaResultObject, propertyMapping);   // TODO is that OK?
+      return DEFERED;
     } else {
       final TypeHandler<?> typeHandler = propertyMapping.getTypeHandler();
       final String column = prependPrefix(propertyMapping.getColumn(), columnPrefix);
@@ -648,17 +651,19 @@ private Object getNestedQueryMappingValue(ResultSet rs, MetaObject metaResultObj
     final MappedStatement nestedQuery = configuration.getMappedStatement(nestedQueryId);
     final Class<?> nestedQueryParameterType = nestedQuery.getParameterMap().getType();
     final Object nestedQueryParameterObject = prepareParameterForNestedQuery(rs, propertyMapping, nestedQueryParameterType, columnPrefix);
-    Object value = NO_VALUE;
+    Object value = null;
     if (nestedQueryParameterObject != null) {
       final BoundSql nestedBoundSql = nestedQuery.getBoundSql(nestedQueryParameterObject);
       final CacheKey key = executor.createCacheKey(nestedQuery, nestedQueryParameterObject, RowBounds.DEFAULT, nestedBoundSql);
       final Class<?> targetType = propertyMapping.getJavaType();
       if (executor.isCached(nestedQuery, key)) {
         executor.deferLoad(nestedQuery, metaResultObject, property, key, targetType);
+        value = DEFERED;
       } else {
         final ResultLoader resultLoader = new ResultLoader(configuration, executor, nestedQuery, nestedQueryParameterObject, targetType, key, nestedBoundSql);
         if (propertyMapping.isLazy()) {
           lazyLoader.addLoader(property, metaResultObject, resultLoader);
+          value = DEFERED;
         } else {
           value = resultLoader.loadResult();
         }

src/test/java/org/apache/ibatis/submitted/call_setters_on_nulls/CallSettersOnNullsTest.java

@@ -107,7 +107,12 @@ public void shouldCallNullOnMapForSingleColumnWithResultMap() {
     try {
       Mapper mapper = sqlSession.getMapper(Mapper.class);
       List<Map<String, Object>> oneColumns = mapper.getNameOnlyMapped();
-      Assert.assertNotNull(oneColumns.get(1));
+//      Assert.assertNotNull(oneColumns.get(1));
+      // TEST changed after fix for #307
+      // When callSetterOnNull is true, setters are called with null values
+      // but if all the values for an object are null
+      // the object itself should be null (same as default behaviour)
+      Assert.assertNull(oneColumns.get(1));
     } finally {
       sqlSession.close();
     }

src/test/java/org/apache/ibatis/submitted/nestedresulthandler_multiple_association/Binome.java

@@ -0,0 +1,49 @@
+package org.apache.ibatis.submitted.nestedresulthandler_multiple_association;
+
+public class Binome<T, U> {
+	private T one;
+	private U two;
+
+	public Binome() {
+	}
+
+	public Binome(final T one, final U two) {
+		this.one = one;
+		this.two = two;
+	}
+
+	public T getOne() {
+		return one;
+	}
+
+	public void setOne(T one) {
+		this.one = one;
+	}
+
+	public U getTwo() {
+		return two;
+	}
+
+	public void setTwo(U two) {
+		this.two = two;
+	}
+
+	@Override
+	public int hashCode() {
+		return (one != null ? one.hashCode() : 0) + (two != null ? two.hashCode() : 0);
+	}
+
+	@Override
+	public boolean equals(final Object obj) {
+		if (obj instanceof Binome<?, ?>) {
+			Binome<?, ?> bin = (Binome<?, ?>) obj;
+			return one != null && one.equals(bin.getOne()) && two != null && two.equals(bin.getTwo());
+		}
+		return super.equals(obj);
+	}
+
+	@Override
+	public String toString() {
+		return "Binome [one=" + one + ", two=" + two + "]";
+	}
+}

src/test/java/org/apache/ibatis/submitted/nestedresulthandler_multiple_association/ChildBean.java

@@ -0,0 +1,27 @@
+package org.apache.ibatis.submitted.nestedresulthandler_multiple_association;
+
+public class ChildBean {
+	private Integer id;
+	private String value;
+
+	public Integer getId() {
+		return id;
+	}
+
+	public void setId(Integer id) {
+		this.id = id;
+	}
+
+	public String getValue() {
+		return value;
+	}
+
+	public void setValue(String value) {
+		this.value = value;
+	}
+
+	@Override
+	public String toString() {
+		return "ChildBean [id=" + id + ", value=" + value + "]";
+	}
+}

src/test/java/org/apache/ibatis/submitted/nestedresulthandler_multiple_association/CreateDB.sql

@@ -0,0 +1,45 @@
+--
+--    Copyright 2009-2014 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
+--
+--       http://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.
+--
+
+DROP TABLE parent if exists;
+DROP TABLE child if exists;
+create table parent(
+	id integer, 
+	value varchar(20)
+);
+
+create table child(
+	id integer, 
+	value varchar(20)
+);
+
+create table parent_child(
+	idparent integer, 
+	idchild_from integer, 
+	idchild_to integer
+);
+
+insert into parent (id, value) values (1, 'parent1');
+insert into parent (id, value) values (2, 'parent2');
+
+insert into child (id, value) values (1, 'child1');
+insert into child (id, value) values (2, 'child2');
+insert into child (id, value) values (3, 'child3');
+insert into child (id, value) values (4, 'child4');
+
+insert into parent_child (idparent, idchild_from, idchild_to) values (1, 1, 2);
+insert into parent_child (idparent, idchild_from, idchild_to) values (2, 2, 3);
+insert into parent_child (idparent, idchild_from, idchild_to) values (2, 1, 2);

src/test/java/org/apache/ibatis/submitted/nestedresulthandler_multiple_association/NestedResultHandlerMultipleAssociationTest.java

@@ -0,0 +1,89 @@
+/*
+ *    Copyright 2009-2014 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
+ *
+ *       http://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.apache.ibatis.submitted.nestedresulthandler_multiple_association;
+
+import java.io.Reader;
+import java.sql.Connection;
+import java.util.List;
+
+import org.apache.ibatis.io.Resources;
+import org.apache.ibatis.jdbc.ScriptRunner;
+import org.apache.ibatis.session.SqlSession;
+import org.apache.ibatis.session.SqlSessionFactory;
+import org.apache.ibatis.session.SqlSessionFactoryBuilder;
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class NestedResultHandlerMultipleAssociationTest {
+
+	private static SqlSessionFactory sqlSessionFactory;
+
+	@BeforeClass
+	public static void setUp() throws Exception {
+		// create an SqlSessionFactory
+		Reader reader = Resources.getResourceAsReader("org/apache/ibatis/submitted/nestedresulthandler_multiple_association/mybatis-config.xml");
+		sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
+		reader.close();
+
+		// populate in-memory database
+		SqlSession session = sqlSessionFactory.openSession();
+		Connection conn = session.getConnection();
+		reader = Resources.getResourceAsReader("org/apache/ibatis/submitted/nestedresulthandler_multiple_association/CreateDB.sql");
+		ScriptRunner runner = new ScriptRunner(conn);
+		runner.setLogWriter(null);
+		runner.runScript(reader);
+		reader.close();
+		session.close();
+	}
+
+	@Test
+	public void failure() throws Exception {
+		SqlSession sqlSession = sqlSessionFactory.openSession();
+
+		// Parents have child going from somewhere to somewhere, they are stored in a Binome object
+		// In this test we have 2 parents:
+		// Parent1 is going from Child1 to Child2
+		// Parent2 is going from Child2 to Child3 and from Child1 to Child2
+		// You'll see a NULL entry in the list instead of the Binome Child1/Child2
+		List<ParentBean> list = sqlSession.selectList("selectParentBeans");
+		for (ParentBean pb : list) {
+			for (Binome<ChildBean, ChildBean> childs : pb.getChilds()) {
+				Assert.assertNotNull(childs);
+				Assert.assertNotNull(childs.getOne());
+				Assert.assertNotNull(childs.getTwo());
+			}
+		}
+
+		sqlSession.close();
+	}
+
+	@Test
+	public void success() throws Exception {
+		SqlSession sqlSession = sqlSessionFactory.openSession();
+
+		ParentBean parent = sqlSession.selectOne("selectParentBeanById", 2);
+
+		// If you only select the Parent2 it works
+		for (Binome<ChildBean, ChildBean> childs : parent.getChilds()) {
+			Assert.assertNotNull(childs);
+			Assert.assertNotNull(childs.getOne());
+			Assert.assertNotNull(childs.getTwo());
+		}
+		sqlSession.close();
+	}
+
+}

src/test/java/org/apache/ibatis/submitted/nestedresulthandler_multiple_association/ParentBean.java

@@ -0,0 +1,42 @@
+package org.apache.ibatis.submitted.nestedresulthandler_multiple_association;
+
+import java.util.List;
+
+public class ParentBean {
+	private Integer id;
+	private String value;
+	private List<Binome<ChildBean, ChildBean>> childs;
+
+	public Integer getId() {
+		return id;
+	}
+
+	public void setId(Integer id) {
+		this.id = id;
+	}
+
+	public String getValue() {
+		return value;
+	}
+
+	public void setValue(String value) {
+		this.value = value;
+	}
+
+	public List<Binome<ChildBean, ChildBean>> getChilds() {
+		return childs;
+	}
+
+	public void setChilds(List<Binome<ChildBean, ChildBean>> childs) {
+		this.childs = childs;
+	}
+
+	@Override
+	public String toString() {
+		StringBuilder sb = new StringBuilder("ParentBean [id=" + id + ", value=" + value + "]\nChilds:\n");
+		for (Binome<ChildBean, ChildBean> binome : childs) {
+			sb.append("\tChild : ").append(binome).append('\n');
+		}
+		return sb.toString();
+	}
+}

src/test/java/org/apache/ibatis/submitted/nestedresulthandler_multiple_association/mapper.xml

@@ -0,0 +1,52 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+       Copyright 2009-2014 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
+
+          http://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.
+-->
+<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 
+"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
+<mapper namespace="mapper">
+    <resultMap id="ParentBeanResultMap" type="org.apache.ibatis.submitted.nestedresulthandler_multiple_association.ParentBean">
+        <id property="id" column="id"/>
+        <result property="value" column="value"/>
+        <collection property="childs" select="selectChildsBinomes" column="id" />
+    </resultMap>
+
+    <resultMap id="ChildsBinomesResultMap" type="org.apache.ibatis.submitted.nestedresulthandler_multiple_association.Binome">
+        <association property="one" select="selectChildBeanById" column="idchild_from" javaType="org.apache.ibatis.submitted.nestedresulthandler_multiple_association.ChildBean" />
+        <association property="two" select="selectChildBeanById" column="idchild_to"  javaType="org.apache.ibatis.submitted.nestedresulthandler_multiple_association.ChildBean" />
+    </resultMap>
+
+    <resultMap id="ChildBeanResultMap" type="org.apache.ibatis.submitted.nestedresulthandler_multiple_association.ChildBean">
+        <id property="id" column="id"/>
+        <result property="value" column="value"/>
+    </resultMap>
+
+    <select id="selectParentBeans" resultMap="ParentBeanResultMap" useCache="false">
+    	select * from parent
+    </select>
+
+    <select id="selectParentBeanById" resultMap="ParentBeanResultMap" useCache="false">
+    	select * from parent where id = #{value}
+    </select>
+
+    <select id="selectChildBeanById" parameterType="java.lang.Integer" resultMap="ChildBeanResultMap" useCache="false">
+    	select * from child where id = #{value}
+    </select>
+
+    <select id="selectChildsBinomes" parameterType="java.lang.Integer" resultMap="ChildsBinomesResultMap" useCache="false">
+    	select * from parent_child where idparent = #{value}
+    </select>
+
+</mapper>