Enable using handlers with mapper interfaces.

Author: emacarron

src/main/java/org/apache/ibatis/binding/MapperMethod.java

@@ -11,6 +11,7 @@
 import org.apache.ibatis.mapping.MappedStatement;
 import org.apache.ibatis.mapping.SqlCommandType;
 import org.apache.ibatis.session.Configuration;
+import org.apache.ibatis.session.ResultHandler;
 import org.apache.ibatis.session.RowBounds;
 import org.apache.ibatis.session.SqlSession;
 
@@ -27,8 +28,10 @@ public class MapperMethod {
 
   private boolean returnsList;
   private boolean returnsMap;
+  private boolean returnsVoid;
   private String mapKey;
 
+  private Integer resultHandlerIndex;
   private Integer rowBoundsIndex;
   private List<String> paramNames;
   private List<Integer> paramPositions;
@@ -50,7 +53,7 @@ public MapperMethod(Class<?> declaringInterface, Method method, SqlSession sqlSe
   }
 
   public Object execute(Object[] args) {
-    Object result;
+    Object result = null;
     if (SqlCommandType.INSERT == type) {
       Object param = getParam(args);
       result = sqlSession.insert(commandName, param);
@@ -61,7 +64,9 @@ public Object execute(Object[] args) {
       Object param = getParam(args);
       result = sqlSession.delete(commandName, param);
     } else if (SqlCommandType.SELECT == type) {
-      if (returnsList) {
+      if (returnsVoid && resultHandlerIndex != null) {
+        executeWithResultHandler(args);
+      } else if (returnsList) {
         result = executeForList(args);
       } else if (returnsMap) {
         result = executeForMap(args);
@@ -75,6 +80,16 @@ public Object execute(Object[] args) {
     return result;
   }
 
+  private void executeWithResultHandler(Object[] args) {
+    Object param = getParam(args);
+    if (rowBoundsIndex != null) {
+      RowBounds rowBounds = (RowBounds) args[rowBoundsIndex];
+      sqlSession.select(commandName, param, rowBounds, (ResultHandler) args[resultHandlerIndex]);
+    } else {
+      sqlSession.select(commandName, param, (ResultHandler) args[resultHandlerIndex]);
+    }
+  }
+
   private List executeForList(Object[] args) {
     List result;
     Object param = getParam(args);
@@ -121,6 +136,9 @@ private void setupFields() {
   }
 
   private void setupMethodSignature() {
+    if( method.getReturnType().equals(Void.TYPE)){
+      returnsVoid = true;
+    }
     if (List.class.isAssignableFrom(method.getReturnType())) {
       returnsList = true;
     }
@@ -135,7 +153,17 @@ private void setupMethodSignature() {
     final Class<?>[] argTypes = method.getParameterTypes();
     for (int i = 0; i < argTypes.length; i++) {
       if (RowBounds.class.isAssignableFrom(argTypes[i])) {
-        rowBoundsIndex = i;
+        if (rowBoundsIndex == null) {
+          rowBoundsIndex = i;
+        } else {
+          throw new BindingException(method.getName() + " cannot have multiple RowBounds parameters");
+        }
+      } else if (ResultHandler.class.isAssignableFrom(argTypes[i])) {
+        if (resultHandlerIndex == null) {
+          resultHandlerIndex = i;
+        } else {
+          throw new BindingException(method.getName() + " cannot have multiple ResultHandler parameters");
+        }
       } else {
         String paramName = String.valueOf(paramPositions.size());
         paramName = getParamNameFromAnnotation(i, paramName);

src/main/java/org/apache/ibatis/binding/MapperProxy.java

@@ -36,7 +36,7 @@ public Object invoke(Object proxy, Method method, Object[] args) throws Throwabl
       final Class<?> declaringInterface = findDeclaringInterface(proxy, method);
       final MapperMethod mapperMethod = new MapperMethod(declaringInterface, method, sqlSession);
       final Object result = mapperMethod.execute(args);
-      if (result == null && method.getReturnType().isPrimitive()) {
+      if (result == null && method.getReturnType().isPrimitive() && !method.getReturnType().equals(Void.TYPE)) {
         throw new BindingException("Mapper method '" + method.getName() + "' (" + method.getDeclaringClass() + ") attempted to return null from a method with a primitive return type (" + method.getReturnType() + ").");
       }
       return result;

src/test/java/domain/blog/mappers/AuthorMapper.java

@@ -4,12 +4,18 @@
 
 import java.util.List;
 
+import org.apache.ibatis.session.ResultHandler;
+
 public interface AuthorMapper {
 
   List selectAllAuthors();
+  
+  void selectAllAuthors(ResultHandler handler);
 
   Author selectAuthor(int id);
 
+  void selectAuthor(int id, ResultHandler handler);
+
   void insertAuthor(Author author);
 
   int deleteAuthor(int id);

src/test/java/domain/blog/mappers/AuthorMapperWithMultipleHandlers.java

@@ -0,0 +1,10 @@
+package domain.blog.mappers;
+
+import org.apache.ibatis.annotations.Select;
+import org.apache.ibatis.session.ResultHandler;
+
+public interface AuthorMapperWithMultipleHandlers {
+  @Select("select id, username, password, email, bio, favourite_section from author where id = #{id}")
+  void selectAuthor(int id, ResultHandler handler1, ResultHandler handler2);
+
+}

src/test/java/domain/blog/mappers/AuthorMapperWithRowBounds.java

@@ -0,0 +1,10 @@
+package domain.blog.mappers;
+
+import org.apache.ibatis.annotations.Select;
+import org.apache.ibatis.session.RowBounds;
+
+public interface AuthorMapperWithRowBounds {
+  @Select("select id, username, password, email, bio, favourite_section from author where id = #{id}")
+  void selectAuthor(int id, RowBounds bounds1, RowBounds bounds2);
+
+}

src/test/java/domain/blog/mappers/CopyOfAuthorMapper.java

@@ -0,0 +1,28 @@
+package domain.blog.mappers;
+
+import domain.blog.Author;
+
+import java.util.List;
+
+import org.apache.ibatis.session.ResultHandler;
+
+public interface CopyOfAuthorMapper {
+
+  List selectAllAuthors();
+
+  void selectAllAuthors(ResultHandler handler);
+
+  Author selectAuthor(int id);
+
+  void selectAuthor(int id, ResultHandler handler);
+
+  void insertAuthor(Author author);
+
+  int deleteAuthor(int id);
+
+  int updateAuthor(Author author);
+
+}
+
+
+

src/test/java/org/apache/ibatis/session/SqlSessionTest.java

@@ -2,11 +2,20 @@
 
 import domain.blog.*;
 import domain.blog.mappers.AuthorMapper;
+import domain.blog.mappers.AuthorMapperWithMultipleHandlers;
+import domain.blog.mappers.AuthorMapperWithRowBounds;
 import domain.blog.mappers.BlogMapper;
 import org.apache.ibatis.BaseDataTest;
+import org.apache.ibatis.binding.BindingException;
 import org.apache.ibatis.cache.impl.PerpetualCache;
+import org.apache.ibatis.exceptions.PersistenceException;
+import org.apache.ibatis.executor.result.DefaultResultHandler;
 import org.apache.ibatis.io.Resources;
+import org.apache.ibatis.mapping.Environment;
+import org.apache.ibatis.session.defaults.DefaultSqlSessionFactory;
+
 import static org.junit.Assert.*;
+
 import org.junit.BeforeClass;
 import org.junit.Test;
 
@@ -476,6 +485,65 @@ public void shouldExecuteSelectOneAuthorUsingMapperClass() {
     }
   }
 
+  @Test
+  public void shouldExecuteSelectOneAuthorUsingMapperClassWithResultHandler() {
+    SqlSession session = sqlMapper.openSession();
+    try {
+      DefaultResultHandler handler = new DefaultResultHandler();
+      AuthorMapper mapper = session.getMapper(AuthorMapper.class);
+      mapper.selectAuthor(101, handler);
+      Author author = (Author) handler.getResultList().get(0);
+      assertEquals(101, author.getId());
+    } finally {
+      session.close();
+    }
+  }
+
+  @Test
+  public void shouldSelectAuthorsUsingMapperClassWithResultHandler() {
+    SqlSession session = sqlMapper.openSession();
+    try {
+      DefaultResultHandler handler = new DefaultResultHandler();
+      AuthorMapper mapper = session.getMapper(AuthorMapper.class);
+      mapper.selectAllAuthors(handler);
+      assertEquals(2, handler.getResultList().size());
+    } finally {
+      session.close();
+    }
+  }
+
+  @Test(expected = BindingException.class)
+  public void shouldFailSelectOneAuthorUsingMapperClassWithTwoResultHandlers() {
+    Configuration configuration = new Configuration(sqlMapper.getConfiguration().getEnvironment());
+    configuration.addMapper(AuthorMapperWithMultipleHandlers.class);
+    SqlSessionFactory sqlMapperWithMultipleHandlers = new DefaultSqlSessionFactory(configuration);
+    SqlSession sqlSession = sqlMapperWithMultipleHandlers.openSession();
+    try {
+      DefaultResultHandler handler1 = new DefaultResultHandler();
+      DefaultResultHandler handler2 = new DefaultResultHandler();
+      AuthorMapperWithMultipleHandlers mapper = sqlSession.getMapper(AuthorMapperWithMultipleHandlers.class);
+      mapper.selectAuthor(101, handler1, handler2);
+    } finally {
+      sqlSession.close();
+    }
+  }
+
+  @Test(expected = BindingException.class)
+  public void shouldFailSelectOneAuthorUsingMapperClassWithTwoRowBounds() {
+    Configuration configuration = new Configuration(sqlMapper.getConfiguration().getEnvironment());
+    configuration.addMapper(AuthorMapperWithRowBounds.class);
+    SqlSessionFactory sqlMapperWithMultipleHandlers = new DefaultSqlSessionFactory(configuration);
+    SqlSession sqlSession = sqlMapperWithMultipleHandlers.openSession();
+    try {
+      RowBounds bounds1 = new RowBounds(0, 1);
+      RowBounds bounds2 = new RowBounds(0, 1);
+      AuthorMapperWithRowBounds mapper = sqlSession.getMapper(AuthorMapperWithRowBounds.class);
+      mapper.selectAuthor(101, bounds1, bounds2);
+    } finally {
+      sqlSession.close();
+    }
+  }
+
   @Test
   public void shouldInsertAuthorUsingMapperClass() throws Exception {
     SqlSession session = sqlMapper.openSession();