give TypeHandler a chance to get Class type info

src/main/java/org/apache/ibatis/executor/result/ResultClassTypeHolder.java

@@ -0,0 +1,19 @@
+package org.apache.ibatis.executor.result;
+
+public class ResultClassTypeHolder {
+
+  // hold the the class type of result
+  private static final ThreadLocal<Class> resultTypeTl = new ThreadLocal();
+
+  public static void setResultType(Class clazz) {
+    resultTypeTl.set(clazz);
+  }
+
+  public static Class getResultType() {
+    return resultTypeTl.get();
+  }
+
+  public static void clean() {
+    resultTypeTl.remove();
+  }
+}

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

@@ -41,6 +41,7 @@
 import org.apache.ibatis.executor.parameter.ParameterHandler;
 import org.apache.ibatis.executor.result.DefaultResultContext;
 import org.apache.ibatis.executor.result.DefaultResultHandler;
+import org.apache.ibatis.executor.result.ResultClassTypeHolder;
 import org.apache.ibatis.executor.result.ResultMapException;
 import org.apache.ibatis.mapping.BoundSql;
 import org.apache.ibatis.mapping.Discriminator;
@@ -293,6 +294,7 @@ private void validateResultMapsCount(ResultSetWrapper rsw, int resultMapCount) {
 
   private void handleResultSet(ResultSetWrapper rsw, ResultMap resultMap, List<Object> multipleResults, ResultMapping parentMapping) throws SQLException {
     try {
+      ResultClassTypeHolder.setResultType(resultMap.getType());
       if (parentMapping != null) {
         handleRowValues(rsw, resultMap, null, RowBounds.DEFAULT, parentMapping);
       } else {
@@ -307,6 +309,7 @@ private void handleResultSet(ResultSetWrapper rsw, ResultMap resultMap, List<Obj
     } finally {
       // issue #228 (close resultsets)
       closeResultSet(rsw.getResultSet());
+      ResultClassTypeHolder.clean();
     }
   }
 

src/test/java/org/apache/ibatis/autoconstructor/AutoConstructorTest.java

@@ -22,11 +22,14 @@
 import java.util.List;
 
 import org.apache.ibatis.BaseDataTest;
+import org.apache.ibatis.builder.typehandler.WidthTypeHandler;
 import org.apache.ibatis.exceptions.PersistenceException;
 import org.apache.ibatis.io.Resources;
+import org.apache.ibatis.session.Configuration;
 import org.apache.ibatis.session.SqlSession;
 import org.apache.ibatis.session.SqlSessionFactory;
 import org.apache.ibatis.session.SqlSessionFactoryBuilder;
+import org.apache.ibatis.type.TypeHandlerRegistry;
 import org.assertj.core.api.Assertions;
 import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
@@ -73,6 +76,9 @@ void annotatedSubject() {
 
   @Test
   void badSubject() {
+    Configuration configuration = sqlSessionFactory.getConfiguration();
+    final TypeHandlerRegistry registry = configuration.getTypeHandlerRegistry();
+    registry.register(BadSubject.Width.class, WidthTypeHandler.class);
     try (SqlSession sqlSession = sqlSessionFactory.openSession()) {
       final AutoConstructorMapper mapper = sqlSession.getMapper(AutoConstructorMapper.class);
       assertThrows(PersistenceException.class, mapper::getBadSubjects);

src/test/java/org/apache/ibatis/autoconstructor/BadSubject.java

@@ -21,16 +21,22 @@ public class BadSubject {
   private final int age;
   private final Height height;
   private final Double weight;
+  private final Width width;
 
-  public BadSubject(final int id, final String name, final int age, final Height height, final Double weight) {
+  public BadSubject(final int id, final String name, final int age, final Height height, final Double weight, final Width width) {
     this.id = id;
     this.name = name;
     this.age = age;
     this.height = height;
     this.weight = weight == null ? 0 : weight;
+    this.width = width;
   }
 
   private class Height {
 
   }
+
+  public static class Width {
+
+  }
 }

src/test/java/org/apache/ibatis/autoconstructor/CreateDB.sql

@@ -27,7 +27,8 @@ CREATE TABLE subject (
   height INT,
   weight INT,
   active BIT,
-  dt     TIMESTAMP
+  dt     TIMESTAMP,
+  width INT
 );
 
 CREATE TABLE extensive_subject (
@@ -47,12 +48,12 @@ CREATE TABLE extensive_subject (
 );
 
 INSERT INTO subject VALUES
-  (1, 'a', 10, 100, 45, 1, CURRENT_TIMESTAMP),
-  (2, 'b', 10, NULL, 45, 1, CURRENT_TIMESTAMP),
-  (2, 'c', 10, NULL, NULL, 0, CURRENT_TIMESTAMP);
+  (1, 'a', 10, 100, 45, 1, CURRENT_TIMESTAMP, 50),
+  (2, 'b', 10, NULL, 45, 1, CURRENT_TIMESTAMP, 50),
+  (2, 'c', 10, NULL, NULL, 0, CURRENT_TIMESTAMP, 50);
 
 INSERT INTO extensive_subject
 VALUES
   (1, 1, 'a', 1, 1, 1, 1.0, 1, 'a', 'AVALUE', 'ACLOB', 'aaaaaabbbbbb', CURRENT_TIMESTAMP),
   (2, 2, 'b', 2, 2, 2, 2.0, 2, 'b', 'BVALUE', 'BCLOB', '010101010101', CURRENT_TIMESTAMP),
-  (3, 3, 'c', 3, 3, 3, 3.0, 3, 'c', 'CVALUE', 'CCLOB', '777d010078da', CURRENT_TIMESTAMP);
+  (3, 3, 'c', 3, 3, 3, 3.0, 3, 'c', 'CVALUE', 'CCLOB', '777d010078da', CURRENT_TIMESTAMP);

src/test/java/org/apache/ibatis/builder/CustomLongTypeHandler.java

@@ -15,15 +15,15 @@
  */
 package org.apache.ibatis.builder;
 
+import org.apache.ibatis.type.JdbcType;
+import org.apache.ibatis.type.MappedTypes;
+import org.apache.ibatis.type.TypeHandler;
+
 import java.sql.CallableStatement;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
 
-import org.apache.ibatis.type.JdbcType;
-import org.apache.ibatis.type.MappedTypes;
-import org.apache.ibatis.type.TypeHandler;
-
 @MappedTypes(Long.class)
 public class CustomLongTypeHandler implements TypeHandler<Long> {
 

src/test/java/org/apache/ibatis/builder/typehandler/WidthTypeHandler.java

@@ -0,0 +1,36 @@
+package org.apache.ibatis.builder.typehandler;
+
+import org.apache.ibatis.autoconstructor.BadSubject;
+import org.apache.ibatis.executor.result.ResultClassTypeHolder;
+import org.apache.ibatis.type.BaseTypeHandler;
+import org.apache.ibatis.type.JdbcType;
+import org.junit.Assert;
+
+import java.sql.CallableStatement;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+public class WidthTypeHandler extends BaseTypeHandler<BadSubject.Width> {
+
+  @Override
+  public void setNonNullParameter(PreparedStatement ps, int i, BadSubject.Width parameter, JdbcType jdbcType) throws SQLException {
+
+  }
+
+  @Override
+  public BadSubject.Width getNullableResult(ResultSet rs, String columnName) throws SQLException {
+    Assert.assertNotNull(ResultClassTypeHolder.getResultType());
+    return new BadSubject.Width();
+  }
+
+  @Override
+  public BadSubject.Width getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
+    return new BadSubject.Width();
+  }
+
+  @Override
+  public BadSubject.Width getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
+    return new BadSubject.Width();
+  }
+}

src/test/java/org/apache/ibatis/executor/ResultClassTypeHolderTest.java

@@ -0,0 +1,25 @@
+package org.apache.ibatis.executor;
+
+import org.apache.ibatis.executor.result.ResultClassTypeHolder;
+import org.junit.Assert;
+import org.junit.jupiter.api.Test;
+
+public class ResultClassTypeHolderTest {
+
+  @Test
+  public void getResultClassFromTl() {
+    try {
+      ResultClassTypeHolder.setResultType(Object.class);
+      getResultClass();
+    }finally {
+      ResultClassTypeHolder.clean();
+    }
+
+  }
+
+  private void getResultClass() {
+    Class aClass = ResultClassTypeHolder.getResultType();
+    Assert.assertNotNull(aClass);
+  }
+
+}