fixes #591 TypeHandlerRegistry#getTypeHandler() now returns a type ha…

…ndler if it's the only choice for a specified javaType regardless of jdbcType it is mapped to. When there are multiple type handlers mapped to a single javaType, one of them must be mapped to null jdbcType.
mybatis · Mar 7, 2016 · b3f0e9f · b3f0e9f
1 parent 0cfa24c
commit b3f0e9f
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Showing 5 changed files with 137 additions and 9 deletions.
diff --git a/src/main/java/org/apache/ibatis/type/TypeHandlerRegistry.java b/src/main/java/org/apache/ibatis/type/TypeHandlerRegistry.java
@@ -174,6 +174,10 @@ private <T> TypeHandler<T> getTypeHandler(Type type, JdbcType jdbcType) {
       if (handler == null) {
         handler = jdbcHandlerMap.get(null);
       }
+      if (handler == null) {
+        // #591
+        handler = pickSoleHandler(jdbcHandlerMap);
+      }
     }
     if (handler == null && type != null && type instanceof Class && Enum.class.isAssignableFrom((Class<?>) type)) {
       handler = new EnumTypeHandler((Class<?>) type);
@@ -182,6 +186,19 @@ private <T> TypeHandler<T> getTypeHandler(Type type, JdbcType jdbcType) {
     return (TypeHandler<T>) handler;
   }
 
+  private TypeHandler<?> pickSoleHandler(Map<JdbcType, TypeHandler<?>> jdbcHandlerMap) {
+    boolean onlyChoice = true;
+    TypeHandler<?> soleHandler = null;
+    for (TypeHandler<?> handler : jdbcHandlerMap.values()) {
+      if (soleHandler != null && !handler.equals(soleHandler)) {
+        onlyChoice = false;
+        break;
+      }
+      soleHandler = handler;
+    }
+    return onlyChoice ? soleHandler : null;
+  }
+
   public TypeHandler<Object> getUnknownTypeHandler() {
     return UNKNOWN_TYPE_HANDLER;
   }

diff --git a/src/test/java/org/apache/ibatis/submitted/typehandler/Mapper.java b/src/test/java/org/apache/ibatis/submitted/typehandler/Mapper.java
@@ -45,6 +45,8 @@ public interface Mapper {
   @Select("select id, name from product where name = #{value}")
   Product getProductByName(String name);
 
+  Product getProductByNameXml(String name);
+
   @Select("select id, name from product where name = #{value}")
   @ConstructorArgs({
     @Arg(id = true, column="id", javaType = ProductId.class, jdbcType=JdbcType.INTEGER),

diff --git a/src/test/java/org/apache/ibatis/submitted/typehandler/Mapper.xml b/src/test/java/org/apache/ibatis/submitted/typehandler/Mapper.xml
@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+       Copyright 2009-2012 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="org.apache.ibatis.submitted.typehandler.Mapper">
+
+	<resultMap type="org.apache.ibatis.submitted.typehandler.Product"
+		id="productResult">
+		<result property="id" column="id" />
+		<result property="name" column="name" />
+	</resultMap>
+
+	<select id="getProductByNameXml" resultMap="productResult">
+		select * from product where name = #{name}
+	</select>
+
+</mapper>
diff --git a/src/test/java/org/apache/ibatis/submitted/typehandler/Product.java b/src/test/java/org/apache/ibatis/submitted/typehandler/Product.java
@@ -94,4 +94,31 @@ public ProductId getNullableResult(CallableStatement cs, int columnIndex) throws
       return id;
     }
   }
+
+  public static class ConstantProductIdTypeHandler extends BaseTypeHandler<ProductId> {
+    @Override
+    public void setNonNullParameter(PreparedStatement ps, int i, ProductId parameter, JdbcType jdbcType) throws SQLException {
+    }
+
+    @Override
+    public ProductId getNullableResult(ResultSet rs, String columnName) throws SQLException {
+      return getConstantId();
+    }
+
+    @Override
+    public ProductId getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
+      return getConstantId();
+    }
+
+    @Override
+    public ProductId getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
+      return getConstantId();
+    }
+
+    private ProductId getConstantId() {
+      ProductId id = new ProductId();
+      id.setValue(999);
+      return id;
+    }
+  }
 }
diff --git a/src/test/java/org/apache/ibatis/submitted/typehandler/TypeHandlerTest.java b/src/test/java/org/apache/ibatis/submitted/typehandler/TypeHandlerTest.java
@@ -20,28 +20,29 @@
 import java.io.Reader;
 import java.sql.Connection;
 
+import org.apache.ibatis.builder.BuilderException;
 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.apache.ibatis.submitted.typehandler.Product.ProductId;
-import org.junit.Assert;
-import org.junit.BeforeClass;
+import org.apache.ibatis.submitted.typehandler.Product.ConstantProductIdTypeHandler;
+import org.apache.ibatis.type.JdbcType;
+import org.junit.Before;
 import org.junit.Test;
 
 public class TypeHandlerTest {
 
-  private static SqlSessionFactory sqlSessionFactory;
+  private SqlSessionFactory sqlSessionFactory;
 
-  @BeforeClass
-  public static void setUp() throws Exception {
+  @Before
+  public void setUp() throws Exception {
     // create a SqlSessionFactory
     Reader reader = Resources.getResourceAsReader("org/apache/ibatis/submitted/typehandler/mybatis-config.xml");
     sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
     reader.close();
     sqlSessionFactory.getConfiguration().getTypeHandlerRegistry().register(StringTrimmingTypeHandler.class);
-    sqlSessionFactory.getConfiguration().addMapper(Mapper.class);
 
     // populate in-memory database
     SqlSession session = sqlSessionFactory.openSession();
@@ -54,22 +55,30 @@ public static void setUp() throws Exception {
     session.close();
   }
 
+  // Some tests need to register additional type handler
+  // before adding mapper.
+  private void addMapper() {
+    sqlSessionFactory.getConfiguration().addMapper(Mapper.class);
+  }
+
   @Test
   public void shouldGetAUser() {
+    addMapper();
     SqlSession sqlSession = sqlSessionFactory.openSession();
     try {
       Mapper mapper = sqlSession.getMapper(Mapper.class);
       User user = mapper.getUser(1);
-      Assert.assertEquals("User1", user.getName());
-      Assert.assertEquals("Carmel", user.getCity());
-      Assert.assertEquals("IN", user.getState());
+      assertEquals("User1", user.getName());
+      assertEquals("Carmel", user.getCity());
+      assertEquals("IN", user.getState());
     } finally {
       sqlSession.close();
     }
   }
 
   @Test
   public void shouldApplyTypeHandlerOnGeneratedKey() {
+    addMapper();
     SqlSession sqlSession = sqlSessionFactory.openSession();
     try {
       Mapper mapper = sqlSession.getMapper(Mapper.class);
@@ -85,6 +94,7 @@ public void shouldApplyTypeHandlerOnGeneratedKey() {
 
   @Test
   public void shouldApplyTypeHandlerWithJdbcTypeSpecified() throws Exception {
+    addMapper();
     SqlSession sqlSession = sqlSessionFactory.openSession();
     try {
       Mapper mapper = sqlSession.getMapper(Mapper.class);
@@ -97,6 +107,7 @@ public void shouldApplyTypeHandlerWithJdbcTypeSpecified() throws Exception {
 
   @Test
   public void shouldApplyTypeHandlerUsingConstructor() throws Exception {
+    addMapper();
     SqlSession sqlSession = sqlSessionFactory.openSession();
     try {
       Mapper mapper = sqlSession.getMapper(Mapper.class);
@@ -109,6 +120,7 @@ public void shouldApplyTypeHandlerUsingConstructor() throws Exception {
 
   @Test
   public void shouldApplyTypeHandlerOnReturnTypeWithJdbcTypeSpecified() throws Exception {
+    addMapper();
     SqlSession sqlSession = sqlSessionFactory.openSession();
     try {
       Mapper mapper = sqlSession.getMapper(Mapper.class);
@@ -118,4 +130,41 @@ public void shouldApplyTypeHandlerOnReturnTypeWithJdbcTypeSpecified() throws Exc
       sqlSession.close();
     }
   }
+
+  @Test
+  public void shouldPickSoleTypeHandlerOnXmlResultMap() throws Exception {
+    addMapper();
+    SqlSession sqlSession = sqlSessionFactory.openSession();
+    try {
+      Mapper mapper = sqlSession.getMapper(Mapper.class);
+      Product product = mapper.getProductByNameXml("iPad");
+      assertEquals(Integer.valueOf(2), product.getId().getValue());
+    } finally {
+      sqlSession.close();
+    }
+  }
+
+  @Test(expected = BuilderException.class)
+  public void shouldFailIfMultipleHandlerMappedToAType() throws Exception {
+    sqlSessionFactory.getConfiguration().getTypeHandlerRegistry().register(ProductId.class, JdbcType.BIGINT, ConstantProductIdTypeHandler.class);
+    // multiple type handlers are mapped to ProductId and
+    // none of them are mapped to null jdbcType.
+    addMapper();
+  }
+
+  @Test
+  public void shouldPickHandlerForNull() throws Exception {
+    sqlSessionFactory.getConfiguration().getTypeHandlerRegistry().register(ProductId.class, null, ConstantProductIdTypeHandler.class);
+    // multiple type handlers are mapped to ProductId and
+    // one of them are mapped to null jdbcType.
+    addMapper();
+    SqlSession sqlSession = sqlSessionFactory.openSession();
+    try {
+      Mapper mapper = sqlSession.getMapper(Mapper.class);
+      Product product = mapper.getProductByNameXml("iPad");
+      assertEquals(Integer.valueOf(999), product.getId().getValue());
+    } finally {
+      sqlSession.close();
+    }
+  }
 }