feat: add BaseMapper.selectCursorByQuery()

mybatis-flex-core/src/main/java/com/mybatisflex/core/BaseMapper.java

@@ -27,6 +27,7 @@ import com.mybatisflex.core.table.TableInfoFactory;
 import com.mybatisflex.core.util.*;
 import org.apache.ibatis.annotations.*;
 import org.apache.ibatis.builder.annotation.ProviderContext;
+import org.apache.ibatis.cursor.Cursor;
 
 import java.io.Serializable;
 import java.util.*;
@@ -442,6 +443,17 @@ public interface BaseMapper<T> {
         return list;
     }
 
+    /**
+     * 根据 query 来构建条件查询游标数据 Cursor
+     * 该方法必须在事务中才能正常使用，非事务下无法获取数据
+     *
+     * @param queryWrapper 查询条件
+     * @return 游标数据 Cursor
+     */
+    @SelectProvider(type = EntitySqlProvider.class, method = "selectListByQuery")
+    Cursor<T> selectCursorByQuery(@Param(FlexConsts.QUERY) QueryWrapper queryWrapper);
+
+
 
     /**
      * 根据 query 来构建条件查询数据列表，要求返回的数据为 asType

mybatis-flex-core/src/main/java/com/mybatisflex/core/mybatis/FlexConfiguration.java

@@ -34,6 +34,7 @@ import org.apache.ibatis.executor.keygen.KeyGenerator;
 import org.apache.ibatis.executor.keygen.NoKeyGenerator;
 import org.apache.ibatis.executor.keygen.SelectKeyGenerator;
 import org.apache.ibatis.executor.parameter.ParameterHandler;
+import org.apache.ibatis.executor.resultset.ResultSetHandler;
 import org.apache.ibatis.executor.statement.StatementHandler;
 import org.apache.ibatis.mapping.*;
 import org.apache.ibatis.session.*;
@@ -93,6 +94,17 @@ public class FlexConfiguration extends Configuration {
         }
     }
 
+
+    @Override
+    public ResultSetHandler newResultSetHandler(Executor executor, MappedStatement mappedStatement
+            , RowBounds rowBounds, ParameterHandler parameterHandler, ResultHandler resultHandler, BoundSql boundSql) {
+//        ResultSetHandler resultSetHandler = new DefaultResultSetHandler(executor, mappedStatement, parameterHandler,
+//                resultHandler, boundSql, rowBounds);
+        ResultSetHandler resultSetHandler = new FlexResultSetHandler(executor, mappedStatement, parameterHandler,
+                resultHandler, boundSql, rowBounds);
+        return (ResultSetHandler) interceptorChain.pluginAll(resultSetHandler);
+    }
+
     /**
      * 替换为 FlexStatementHandler，主要用来为实体类的多主键做支持、和数据审计
      * FlexStatementHandler 和 原生的 RoutingStatementHandler 对比，没有任何性能影响

mybatis-flex-core/src/main/java/com/mybatisflex/core/mybatis/FlexResultSetHandler.java

@@ -0,0 +1,90 @@
+/*
+ *  Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
+ *  <p>
+ *  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
+ *  <p>
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *  <p>
+ *  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 com.mybatisflex.core.mybatis;
+
+import com.mybatisflex.core.transaction.TransactionContext;
+import org.apache.ibatis.cursor.Cursor;
+import org.apache.ibatis.cursor.defaults.DefaultCursor;
+import org.apache.ibatis.executor.Executor;
+import org.apache.ibatis.executor.parameter.ParameterHandler;
+import org.apache.ibatis.executor.resultset.DefaultResultSetHandler;
+import org.apache.ibatis.mapping.BoundSql;
+import org.apache.ibatis.mapping.MappedStatement;
+import org.apache.ibatis.session.ResultHandler;
+import org.apache.ibatis.session.RowBounds;
+
+import java.sql.SQLException;
+import java.sql.Statement;
+import java.util.Iterator;
+
+public class FlexResultSetHandler extends DefaultResultSetHandler {
+
+    public FlexResultSetHandler(Executor executor, MappedStatement mappedStatement, ParameterHandler parameterHandler, ResultHandler<?> resultHandler, BoundSql boundSql, RowBounds rowBounds) {
+        super(executor, mappedStatement, parameterHandler, resultHandler, boundSql, rowBounds);
+    }
+
+    @Override
+    public <E> Cursor<E> handleCursorResultSets(Statement stmt) throws SQLException {
+        return new FlexCursor<>(super.handleCursorResultSets(stmt));
+    }
+
+    static class FlexCursor<T> extends DefaultCursor<T> {
+
+        private Cursor originalCursor;
+
+        public FlexCursor(Cursor cursor) {
+            super(null, null, null, null);
+            this.originalCursor = cursor;
+            TransactionContext.holdCursor(cursor);
+        }
+
+        @Override
+        public void close() {
+            //非事务场景下，通过 releaseCursor 对 cursor 进行 close
+            if (TransactionContext.getXID() == null) {
+                TransactionContext.releaseCursor();
+            }
+            //else 在事务的场景下，由事务主动关闭
+        }
+
+        @Override
+        public boolean isOpen() {
+            return originalCursor.isOpen();
+        }
+
+        @Override
+        public boolean isConsumed() {
+            return originalCursor.isConsumed();
+        }
+
+        @Override
+        public int getCurrentIndex() {
+            return originalCursor.getCurrentIndex();
+        }
+
+        @Override
+        public Iterator<T> iterator() {
+            try {
+                return originalCursor.iterator();
+            } catch (IllegalStateException e) {
+                if (TransactionContext.getXID() == null) {
+                    throw new IllegalStateException(e.getMessage() + " Cursor must use in transaction.");
+                }
+                throw e;
+            }
+        }
+    }
+}

mybatis-flex-core/src/main/java/com/mybatisflex/core/mybatis/FlexSqlSessionFactoryBuilder.java

@@ -37,7 +37,7 @@ public class FlexSqlSessionFactoryBuilder extends SqlSessionFactoryBuilder {
     @Override
     public SqlSessionFactory build(Reader reader, String environment, Properties properties) {
         try {
-            // 需要 mybaits v3.5.13+
+            // 需要 mybatis v3.5.13+
             // https://github.com/mybatis/mybatis-3/commit/d7826d71a7005a8b4d4e0e7a020db0f6c7e253a4
             XMLConfigBuilder parser = new XMLConfigBuilder(FlexConfiguration.class, reader, environment, properties);
             return build(parser.parse());
@@ -59,7 +59,7 @@ public class FlexSqlSessionFactoryBuilder extends SqlSessionFactoryBuilder {
     @Override
     public SqlSessionFactory build(InputStream inputStream, String environment, Properties properties) {
         try {
-            // 需要 mybaits v3.5.13+
+            // 需要 mybatis v3.5.13+
             // https://github.com/mybatis/mybatis-3/commit/d7826d71a7005a8b4d4e0e7a020db0f6c7e253a4
             XMLConfigBuilder parser = new XMLConfigBuilder(FlexConfiguration.class, inputStream, environment, properties);
             return build(parser.parse());

mybatis-flex-core/src/main/java/com/mybatisflex/core/transaction/TransactionContext.java

@@ -16,11 +16,16 @@
 package com.mybatisflex.core.transaction;
 
 
+import org.apache.ibatis.cursor.Cursor;
+
+import java.io.IOException;
+
 public class TransactionContext {
 
     private TransactionContext() {}
 
     private static final ThreadLocal<String> XID_HOLDER = new ThreadLocal<>();
+    private static final ThreadLocal<Cursor<?>> CURSOR_HOLDER = new ThreadLocal<>();
 
     public static String getXID() {
         return XID_HOLDER.get();
@@ -28,10 +33,29 @@ public class TransactionContext {
 
     public static void release() {
         XID_HOLDER.remove();
+        releaseCursor();
     }
 
-    public static void hold(String xid) {
+    public static void releaseCursor() {
+        try {
+            Cursor<?> cursor = CURSOR_HOLDER.get();
+            if (cursor != null){
+                try {
+                    cursor.close();
+                } catch (IOException e) {
+                }
+            }
+        }finally {
+            CURSOR_HOLDER.remove();
+        }
+    }
+
+    public static void holdXID(String xid) {
         XID_HOLDER.set(xid);
     }
 
+    public static void holdCursor(Cursor<?> cursor) {
+        CURSOR_HOLDER.set(cursor);
+    }
+
 }

mybatis-flex-core/src/main/java/com/mybatisflex/core/transaction/TransactionalManager.java

@@ -113,7 +113,7 @@ public class TransactionalManager {
         } finally {
             //恢复上一级事务
             if (currentXID != null) {
-                TransactionContext.hold(currentXID);
+                TransactionContext.holdXID(currentXID);
             }
         }
     }
@@ -147,7 +147,7 @@ public class TransactionalManager {
 
     public static String startTransactional() {
         String xid = UUID.randomUUID().toString();
-        TransactionContext.hold(xid);
+        TransactionContext.holdXID(xid);
         return xid;
     }
 

mybatis-flex-spring/src/main/java/com/mybatisflex/spring/FlexTransactionManager.java

@@ -46,7 +46,7 @@ public class FlexTransactionManager extends AbstractPlatformTransactionManager {
     @Override
     protected void doResume(Object transaction, Object suspendedResources) throws TransactionException {
         String xid = (String) suspendedResources;
-        TransactionContext.hold(xid);
+        TransactionContext.holdXID(xid);
     }
 
     @Override

mybatis-flex-test/mybatis-flex-native-test/src/main/java/com/mybatisflex/test/EntityTestStarter.java

@@ -19,13 +19,16 @@ import com.mybatisflex.core.MybatisFlexBootstrap;
 import com.mybatisflex.core.audit.AuditManager;
 import com.mybatisflex.core.audit.ConsoleMessageCollector;
 import com.mybatisflex.core.audit.MessageCollector;
-import com.mybatisflex.core.paginate.Page;
 import com.mybatisflex.core.query.QueryWrapper;
+import com.mybatisflex.core.row.Db;
+import org.apache.ibatis.cursor.Cursor;
 import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseBuilder;
 import org.springframework.jdbc.datasource.embedded.EmbeddedDatabaseType;
 
 import javax.sql.DataSource;
 
+import java.util.function.Supplier;
+
 import static com.mybatisflex.test.table.AccountTableDef.ACCOUNT;
 import static com.mybatisflex.test.table.ArticleTableDef.ARTICLE;
 
@@ -138,8 +141,30 @@ public class EntityTestStarter {
 //
 //        List<ArticleDTO> articleDTOS = accountMapper.selectListByQueryAs(asWrapper, ArticleDTO.class);
 //        System.out.println(articleDTOS);
-        Page<ArticleDTO01> paginate = accountMapper.paginateAs(Page.of(1, 10), asWrapper, ArticleDTO01.class);
-        System.out.println(paginate);
+//        Page<ArticleDTO01> paginate = accountMapper.paginateAs(Page.of(1, 10), asWrapper, ArticleDTO01.class);
+//        System.out.println(paginate);
+
+        Db.tx(new Supplier<Boolean>() {
+            @Override
+            public Boolean get() {
+                Cursor<Account> accounts = accountMapper.selectCursorByQuery(asWrapper);
+                System.out.println(accounts.isOpen());
+                for (Account account : accounts) {
+                    System.out.println(accounts.isOpen());
+                    System.out.println(account);
+                }
+                System.out.println(accounts.isOpen());
+                return true;
+            }
+        });
+
+//        Cursor<Account> accounts = accountMapper.selectCursorByQuery(asWrapper);
+//        System.out.println(accounts.isOpen());
+//        for (Account account : accounts) {
+//            System.out.println(accounts.isOpen());
+//            System.out.println(account);
+//        }
+//        System.out.println(accounts.isOpen());
 
 
 //        QueryWrapper queryWrapper = new QueryWrapper();