View Javadoc
1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.shardingsphere.distsql.parser.core.kernel;
19  
20  import org.antlr.v4.runtime.tree.ErrorNode;
21  import org.apache.shardingsphere.sql.parser.api.ASTNode;
22  import org.apache.shardingsphere.sql.parser.core.ParseASTNode;
23  import org.apache.shardingsphere.sql.parser.core.SQLParserFactory;
24  import org.apache.shardingsphere.sql.parser.exception.SQLParsingException;
25  import org.apache.shardingsphere.sql.parser.sql.common.statement.SQLStatement;
26  
27  /**
28   * SQL statement parser engine for kernel DistSQL.
29   */
30  public final class KernelDistSQLStatementParserEngine {
31      
32      /**
33       * Parse SQL.
34       *
35       * @param sql SQL to be parsed
36       * @return SQL statement
37       */
38      public SQLStatement parse(final String sql) {
39          ASTNode astNode = SQLParserFactory.newInstance(sql, KernelDistSQLLexer.class, KernelDistSQLParser.class).parse();
40          return getSQLStatement(sql, (ParseASTNode) astNode);
41      }
42      
43      private SQLStatement getSQLStatement(final String sql, final ParseASTNode parseASTNode) {
44          if (parseASTNode.getRootNode() instanceof ErrorNode) {
45              throw new SQLParsingException(sql);
46          }
47          return (SQLStatement) (new KernelDistSQLStatementVisitor()).visit(parseASTNode.getRootNode());
48      }
49  }