add limit to rewrite module

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/rewrite/LimitUtils.java

+/*
+ * Copyright 1999-2015 dangdang.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
+ *
+ *      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.
+ * </p>
+ */
+
+package com.dangdang.ddframe.rdb.sharding.rewrite;
+
+import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.LimitContext;
+import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.SQLContext;
+import com.dangdang.ddframe.rdb.sharding.parsing.parser.exception.SQLParsingException;
+
+import java.util.List;
+
+/**
+ * 补列工具类.
+ *
+ * @author zhangliang
+ */
+public final class LimitUtils {
+    
+    /**
+     * 追加分页.
+     * 
+     * @param sqlContext SQL上下文
+     * @param parameters 参数
+     */
+    public static void appendLimit(final SQLContext sqlContext, final List<Object> parameters) {
+        int offset = -1 == sqlContext.getLimitContext().getOffsetParameterIndex()
+                ? sqlContext.getLimitContext().getOffset() : (int) parameters.get(sqlContext.getLimitContext().getOffsetParameterIndex());
+        int rowCount = -1 == sqlContext.getLimitContext().getRowCountParameterIndex()
+                ? sqlContext.getLimitContext().getRowCount() : (int) parameters.get(sqlContext.getLimitContext().getRowCountParameterIndex());
+        sqlContext.setLimitContext(new LimitContext(offset, rowCount, sqlContext.getLimitContext().getOffsetParameterIndex(), sqlContext.getLimitContext().getRowCountParameterIndex()));
+        if (offset < 0 || rowCount < 0) {
+            throw new SQLParsingException("LIMIT offset and row count can not be a negative value.");
+        }
+    }
+}

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/rewrite/SQLRewriteEngine.java

@@ -18,6 +18,7 @@
 package com.dangdang.ddframe.rdb.sharding.rewrite;
 
 
+import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.LimitContext;
 import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.SQLContext;
 import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.TableContext;
 import com.dangdang.ddframe.rdb.sharding.parsing.parser.token.ItemsToken;
@@ -46,6 +47,8 @@ public final class SQLRewriteEngine {
     
     private final Collection<String> tableNames = new TreeSet<>(String.CASE_INSENSITIVE_ORDER);
     
+    private final LimitContext limit;
+    
     private SQLBuilder sqlBuilder;
     
     public SQLRewriteEngine(final String originalSQL, final SQLContext sqlContext) {
@@ -54,10 +57,11 @@ public final class SQLRewriteEngine {
         for (TableContext each : sqlContext.getTables()) {
             tableNames.add(each.getName());
         }
+        limit = sqlContext.getLimitContext();
     }
     
     /**
-     * SQL重写.
+     * SQL改写.
      * 
      * @return SQL构建器
      */

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/router/PreparedSQLRouter.java

@@ -21,9 +21,7 @@ import com.dangdang.ddframe.rdb.sharding.api.rule.ShardingRule;
 import com.dangdang.ddframe.rdb.sharding.api.rule.TableRule;
 import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.GeneratedKeyContext;
 import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.InsertSQLContext;
-import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.LimitContext;
 import com.dangdang.ddframe.rdb.sharding.parsing.parser.context.SQLContext;
-import com.dangdang.ddframe.rdb.sharding.parsing.parser.exception.SQLParsingException;
 import com.google.common.base.Optional;
 import lombok.RequiredArgsConstructor;
 
@@ -61,25 +59,9 @@ public class PreparedSQLRouter {
             List<Number> generatedIds = generateId();
             parameters.addAll(generatedIds);
         }
-        // TODO 提炼至rewrite模块
-        setLimit(parameters);
         return engine.routeSQL(logicSql, sqlContext, parameters);
     }
     
-    private void setLimit(final List<Object> parameters) {
-        if (null == sqlContext.getLimitContext()) {
-            return;
-        }
-        int offset = -1 == sqlContext.getLimitContext().getOffsetParameterIndex()
-                ? sqlContext.getLimitContext().getOffset() : (int) parameters.get(sqlContext.getLimitContext().getOffsetParameterIndex());
-        int rowCount = -1 == sqlContext.getLimitContext().getRowCountParameterIndex()
-                ? sqlContext.getLimitContext().getRowCount() : (int) parameters.get(sqlContext.getLimitContext().getRowCountParameterIndex());
-        sqlContext.setLimitContext(new LimitContext(offset, rowCount, sqlContext.getLimitContext().getOffsetParameterIndex(), sqlContext.getLimitContext().getRowCountParameterIndex()));
-        if (offset < 0 || rowCount < 0) {
-            throw new SQLParsingException("LIMIT offset and row count can not be a negative value.");
-        }
-    }
-    
     private List<Number> generateId() {
         if (!(sqlContext instanceof InsertSQLContext)) {
             return Collections.emptyList();

sharding-jdbc-core/src/main/java/com/dangdang/ddframe/rdb/sharding/router/SQLRouteEngine.java

@@ -36,6 +36,7 @@ import com.dangdang.ddframe.rdb.sharding.parsing.parser.token.OffsetLimitToken;
 import com.dangdang.ddframe.rdb.sharding.parsing.parser.token.RowCountLimitToken;
 import com.dangdang.ddframe.rdb.sharding.rewrite.DerivedColumnUtils;
 import com.dangdang.ddframe.rdb.sharding.rewrite.GenerateKeysUtils;
+import com.dangdang.ddframe.rdb.sharding.rewrite.LimitUtils;
 import com.dangdang.ddframe.rdb.sharding.rewrite.SQLBuilder;
 import com.dangdang.ddframe.rdb.sharding.rewrite.SQLRewriteEngine;
 import com.dangdang.ddframe.rdb.sharding.router.binding.BindingTablesRouter;
@@ -102,6 +103,9 @@ public final class SQLRouteEngine {
         if (result instanceof SelectSQLContext) {
             DerivedColumnUtils.appendDerivedColumns((SelectSQLContext) result);
         }
+        if (null != result.getLimitContext()) {
+            LimitUtils.appendLimit(result, parameters);
+        }
         return result;
     }