Added selectMap functionality for selecting Maps of results keyed by a property

cbegin · cbegin · commit 50afa6960277 · 2010-10-31T17:25:39.000Z
diff --git a/src/main/java/org/apache/ibatis/annotations/MapKey.java b/src/main/java/org/apache/ibatis/annotations/MapKey.java
@@ -0,0 +1,14 @@
+package org.apache.ibatis.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.METHOD)
+public @interface MapKey {
+
+  String value();
+
+}
diff --git a/src/main/java/org/apache/ibatis/binding/MapperMethod.java b/src/main/java/org/apache/ibatis/binding/MapperMethod.java
@@ -6,6 +6,7 @@
 import java.util.List;
 import java.util.Map;
 
+import org.apache.ibatis.annotations.MapKey;
 import org.apache.ibatis.annotations.Param;
 import org.apache.ibatis.mapping.MappedStatement;
 import org.apache.ibatis.mapping.SqlCommandType;
@@ -25,6 +26,8 @@ public class MapperMethod {
   private Method method;
 
   private boolean returnsList;
+  private boolean returnsMap;
+  private String mapKey;
 
   private Integer rowBoundsIndex;
   private List<String> paramNames;
@@ -60,6 +63,8 @@ public Object execute(Object[] args) {
     } else if (SqlCommandType.SELECT == type) {
       if (returnsList) {
         result = executeForList(args);
+      } else if (returnsMap) {
+        result = executeForMap(args);
       } else {
         Object param = getParam(args);
         result = sqlSession.selectOne(commandName, param);
@@ -70,19 +75,30 @@ public Object execute(Object[] args) {
     return result;
   }
 
-  private Object executeForList(Object[] args) {
-    Object result;
+  private List executeForList(Object[] args) {
+    List result;
+    Object param = getParam(args);
     if (rowBoundsIndex != null) {
-      Object param = getParam(args);
       RowBounds rowBounds = (RowBounds) args[rowBoundsIndex];
       result = sqlSession.selectList(commandName, param, rowBounds);
     } else {
-      Object param = getParam(args);
       result = sqlSession.selectList(commandName, param);
     }
     return result;
   }
 
+  private Map executeForMap(Object[] args) {
+    Map result;
+    Object param = getParam(args);
+    if (rowBoundsIndex != null) {
+      RowBounds rowBounds = (RowBounds) args[rowBoundsIndex];
+      result = sqlSession.selectMap(commandName, param, mapKey, rowBounds);
+    } else {
+      result = sqlSession.selectMap(commandName, param, mapKey);
+    }
+    return result;
+  }
+
   private Object getParam(Object[] args) {
     final int paramCount = paramPositions.size();
     if (args == null || paramCount == 0) {
@@ -108,6 +124,14 @@ private void setupMethodSignature() {
     if (List.class.isAssignableFrom(method.getReturnType())) {
       returnsList = true;
     }
+    if (Map.class.isAssignableFrom(method.getReturnType())) { 
+      final MapKey mapKeyAnnotation = method.getAnnotation(MapKey.class);
+      if (mapKeyAnnotation != null) {
+        mapKey = mapKeyAnnotation.value();
+        returnsMap = true;
+      }
+    }
+
     final Class<?>[] argTypes = method.getParameterTypes();
     for (int i = 0; i < argTypes.length; i++) {
       if (RowBounds.class.isAssignableFrom(argTypes[i])) {
diff --git a/src/main/java/org/apache/ibatis/builder/annotation/MapperAnnotationBuilder.java b/src/main/java/org/apache/ibatis/builder/annotation/MapperAnnotationBuilder.java
@@ -278,7 +278,19 @@ private Class<?> getReturnType(Method method) {
           }
         }
       }
+    } else if (Map.class.isAssignableFrom(returnType)) {
+      Type returnTypeParameter = method.getGenericReturnType();
+      if (returnTypeParameter instanceof ParameterizedType) {
+        Type[] actualTypeArguments = ((ParameterizedType) returnTypeParameter).getActualTypeArguments();
+        if (actualTypeArguments != null && actualTypeArguments.length == 2) {
+          returnTypeParameter = actualTypeArguments[1];
+          if (returnTypeParameter instanceof Class) {
+            returnType = (Class<?>) returnTypeParameter;
+          }
+        }
+      }
     }
+
     return returnType;
   }
 
diff --git a/src/main/java/org/apache/ibatis/executor/result/DefaultMapResultHandler.java b/src/main/java/org/apache/ibatis/executor/result/DefaultMapResultHandler.java
@@ -0,0 +1,29 @@
+package org.apache.ibatis.executor.result;
+
+import org.apache.ibatis.reflection.MetaObject;
+import org.apache.ibatis.session.ResultContext;
+import org.apache.ibatis.session.ResultHandler;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class DefaultMapResultHandler implements ResultHandler {
+
+  private final Map mappedResults = new HashMap();
+  private final String mapKey;
+
+  public DefaultMapResultHandler(String mapKey) {
+    this.mapKey = mapKey;
+  }
+
+  public void handleResult(ResultContext context) {
+    final Object value = context.getResultObject();
+    final MetaObject mo = MetaObject.forObject(value);
+    final Object key = mo.getValue(mapKey);
+    mappedResults.put(key, value);
+  }
+
+  public Map getMappedResults() {
+    return mappedResults;
+  }
+}
diff --git a/src/main/java/org/apache/ibatis/session/SqlSession.java b/src/main/java/org/apache/ibatis/session/SqlSession.java
@@ -2,6 +2,7 @@
 
 import java.sql.Connection;
 import java.util.List;
+import java.util.Map;
 
 public interface SqlSession {
 
@@ -15,6 +16,12 @@ public interface SqlSession {
 
   List selectList(String statement, Object parameter, RowBounds rowBounds);
 
+  Map selectMap(String statement, String mapKey);
+
+  Map selectMap(String statement, Object parameter, String mapKey);
+
+  Map selectMap(String statement, Object parameter, String mapKey, RowBounds rowBounds);
+  
   void select(String statement, Object parameter, ResultHandler handler);
 
   void select(String statement, ResultHandler handler);
diff --git a/src/main/java/org/apache/ibatis/session/SqlSessionManager.java b/src/main/java/org/apache/ibatis/session/SqlSessionManager.java
@@ -8,6 +8,7 @@
 import java.lang.reflect.Proxy;
 import java.sql.Connection;
 import java.util.List;
+import java.util.Map;
 import java.util.Properties;
 
 public class SqlSessionManager implements SqlSessionFactory, SqlSession {
@@ -121,6 +122,18 @@ public Object selectOne(String statement, Object parameter) {
     return sqlSessionProxy.selectOne(statement, parameter);
   }
 
+  public Map selectMap(String statement, String mapKey) {
+    return sqlSessionProxy.selectMap(statement, mapKey);
+  }
+
+  public Map selectMap(String statement, Object parameter, String mapKey) {
+    return sqlSessionProxy.selectMap(statement, parameter, mapKey);
+  }
+
+  public Map selectMap(String statement, Object parameter, String mapKey, RowBounds rowBounds) {
+    return sqlSessionProxy.selectMap(statement, parameter, mapKey, rowBounds);
+  }
+
   public List selectList(String statement) {
     return sqlSessionProxy.selectList(statement);
   }
diff --git a/src/main/java/org/apache/ibatis/session/defaults/DefaultSqlSession.java b/src/main/java/org/apache/ibatis/session/defaults/DefaultSqlSession.java
@@ -4,6 +4,7 @@
 import org.apache.ibatis.exceptions.TooManyResultsException;
 import org.apache.ibatis.executor.Executor;
 import org.apache.ibatis.executor.ErrorContext;
+import org.apache.ibatis.executor.result.DefaultMapResultHandler;
 import org.apache.ibatis.mapping.MappedStatement;
 import org.apache.ibatis.session.Configuration;
 import org.apache.ibatis.session.ResultHandler;
@@ -13,6 +14,7 @@
 import java.sql.Connection;
 import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 public class DefaultSqlSession implements SqlSession {
 
@@ -45,6 +47,20 @@ public Object selectOne(String statement, Object parameter) {
     }
   }
 
+  public Map selectMap(String statement, String mapKey) {
+    return selectMap(statement, null, mapKey, RowBounds.DEFAULT);
+  }
+
+  public Map selectMap(String statement, Object parameter, String mapKey) {
+    return selectMap(statement, parameter, mapKey, RowBounds.DEFAULT);
+  }
+
+  public Map selectMap(String statement, Object parameter, String mapKey, RowBounds rowBounds) {
+    final DefaultMapResultHandler mapResultHandler = new DefaultMapResultHandler(mapKey);
+    select(statement, parameter, rowBounds, mapResultHandler);
+    return mapResultHandler.getMappedResults();
+  }
+
   public List selectList(String statement) {
     return selectList(statement, null);
   }
diff --git a/src/test/java/org/apache/ibatis/binding/BindingTest.java b/src/test/java/org/apache/ibatis/binding/BindingTest.java
@@ -8,10 +8,7 @@
 import org.junit.BeforeClass;
 import org.junit.Test;
 
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 
 public class BindingTest {
   private static SqlSessionFactory sqlSessionFactory;
@@ -122,6 +119,21 @@ public void shouldExecuteBoundSelectListOfBlogsStatement() {
     }
   }
 
+  @Test
+  public void shouldExecuteBoundSelectMapOfBlogsById() {
+    SqlSession session = sqlSessionFactory.openSession();
+    try {
+      BoundBlogMapper mapper = session.getMapper(BoundBlogMapper.class);
+      Map<Integer,Blog> blogs = mapper.selectBlogsAsMapById();
+      assertEquals(2, blogs.size());
+      for(Map.Entry<Integer,Blog> blogEntry : blogs.entrySet()) {
+        assertEquals(blogEntry.getKey(), blogEntry.getValue().getId());
+      }
+    } finally {
+      session.close();
+    }
+  }
+
   @Test
   public void shouldSelectListOfBlogsUsingXMLConfig() {
     SqlSession session = sqlSessionFactory.openSession();
diff --git a/src/test/java/org/apache/ibatis/binding/BoundBlogMapper.java b/src/test/java/org/apache/ibatis/binding/BoundBlogMapper.java
@@ -22,6 +22,12 @@ public interface BoundBlogMapper {
 
   //======================================================
 
+  @Select({ "SELECT * FROM blog"})
+  @MapKey("id")
+  Map<Integer,Blog> selectBlogsAsMapById();
+
+  //======================================================
+
   @Select({
       "SELECT *",
       "FROM blog"
diff --git a/src/test/java/org/apache/ibatis/session/SqlSessionTest.java b/src/test/java/org/apache/ibatis/session/SqlSessionTest.java
@@ -11,10 +11,7 @@
 import org.junit.Test;
 
 import java.io.Reader;
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
+import java.util.*;
 
 public class SqlSessionTest extends BaseDataTest {
   private static SqlSessionFactory sqlMapper;
@@ -100,6 +97,20 @@ public void shouldSelectAllAuthors() throws Exception {
     }
   }
 
+  @Test
+  public void shouldSelectAllAuthorsAsMap() throws Exception {
+    SqlSession session = sqlMapper.openSession(TransactionIsolationLevel.SERIALIZABLE);
+    try {
+      final Map<Integer,Author> authors = session.selectMap("domain.blog.mappers.AuthorMapper.selectAllAuthors", "id");
+      assertEquals(2, authors.size());
+      for(Map.Entry<Integer,Author> authorEntry : authors.entrySet()) {
+        assertEquals(authorEntry.getKey(), authorEntry.getValue().getId());
+      }
+    } finally {
+      session.close();
+    }
+  }
+
   @Test
   public void shouldSelectCountOfPosts() throws Exception {
     SqlSession session = sqlMapper.openSession();

Original file line number	Diff line number	Diff line change
`@@ -278,7 +278,19 @@ private Class<?> getReturnType(Method method) {`
`278`	`278`	`}`
`279`	`279`	`}`
`280`	`280`	`}`
	`281`	`+ } else if (Map.class.isAssignableFrom(returnType)) {`
	`282`	`+ Type returnTypeParameter = method.getGenericReturnType();`
	`283`	`+ if (returnTypeParameter instanceof ParameterizedType) {`
	`284`	`+ Type[] actualTypeArguments = ((ParameterizedType) returnTypeParameter).getActualTypeArguments();`
	`285`	`+ if (actualTypeArguments != null && actualTypeArguments.length == 2) {`
	`286`	`+ returnTypeParameter = actualTypeArguments[1];`
	`287`	`+ if (returnTypeParameter instanceof Class) {`
	`288`	`+ returnType = (Class<?>) returnTypeParameter;`
	`289`	`+ }`
	`290`	`+ }`
	`291`	`+ }`
`281`	`292`	`}`
	`293`	`+`
`282`	`294`	`return returnType;`
`283`	`295`	`}`
`284`	`296`