add db2 sql parser support

pom.xml

@@ -529,9 +529,9 @@
 		</dependency>
 
 		<dependency>
-			<groupId>com.alibaba</groupId>
-			<artifactId>fastjson</artifactId>
-			<version>1.1.33</version>
+			<groupId>com.yammer.metrics</groupId>
+			<artifactId>metrics-core</artifactId>
+			<version>2.2.0</version>
 			<scope>test</scope>
 		</dependency>
 	</dependencies>

src/main/java/com/alibaba/druid/sql/PagerUtils.java

@@ -33,6 +33,7 @@
 import com.alibaba.druid.sql.ast.statement.SQLSelectStatement;
 import com.alibaba.druid.sql.ast.statement.SQLSubqueryTableSource;
 import com.alibaba.druid.sql.ast.statement.SQLUnionQuery;
+import com.alibaba.druid.sql.dialect.db2.ast.stmt.DB2SelectQueryBlock;
 import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock;
 import com.alibaba.druid.sql.dialect.mysql.ast.statement.MySqlSelectQueryBlock.Limit;
 import com.alibaba.druid.sql.dialect.oracle.ast.expr.OracleAggregateExpr;
@@ -226,6 +227,10 @@ private static SQLSelectQueryBlock createQueryBlock(String dbType) {
         if (JdbcConstants.SQL_SERVER.equals(dbType)) {
             return new SQLServerSelectQueryBlock();
         }
+
+        if (JdbcConstants.DB2.equals(dbType)) {
+            return new DB2SelectQueryBlock();
+        }
 
         return new SQLSelectQueryBlock();
     }

src/main/java/com/alibaba/druid/sql/SQLUtils.java

@@ -21,6 +21,8 @@
 import com.alibaba.druid.sql.ast.SQLExpr;
 import com.alibaba.druid.sql.ast.SQLObject;
 import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.dialect.db2.visitor.DB2OutputVisitor;
+import com.alibaba.druid.sql.dialect.db2.visitor.DB2SchemaStatVisitor;
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlOutputVisitor;
 import com.alibaba.druid.sql.dialect.mysql.visitor.MySqlSchemaStatVisitor;
 import com.alibaba.druid.sql.dialect.oracle.visitor.OracleOutputVisitor;
@@ -38,8 +40,8 @@
 import com.alibaba.druid.sql.visitor.SchemaStatVisitor;
 import com.alibaba.druid.support.logging.Log;
 import com.alibaba.druid.support.logging.LogFactory;
-import com.alibaba.druid.util.JdbcUtils;
 import com.alibaba.druid.util.JdbcConstants;
+import com.alibaba.druid.util.JdbcUtils;
 import com.alibaba.druid.util.StringUtils;
 
 
@@ -201,6 +203,10 @@ public static SQLASTOutputVisitor createFormatOutputVisitor(Appendable out, List
         if (JdbcUtils.JTDS.equals(dbType)) {
             return new SQLServerOutputVisitor(out);
         }
+
+        if (JdbcUtils.DB2.equals(dbType)) {
+            return new DB2OutputVisitor(out);
+        }
 
         return new SQLASTOutputVisitor(out);
     }
@@ -231,6 +237,10 @@ public static SchemaStatVisitor createSchemaStatVisitor(List<SQLStatement> state
         if (JdbcUtils.JTDS.equals(dbType)) {
             return new SQLServerSchemaStatVisitor();
         }
+
+        if (JdbcUtils.DB2.equals(dbType)) {
+            return new DB2SchemaStatVisitor();
+        }
 
         return new SchemaStatVisitor();
     }

src/main/java/com/alibaba/druid/sql/dialect/db2/ast/stmt/DB2SelectQueryBlock.java

@@ -0,0 +1,25 @@
+/*
+ * Copyright 1999-2011 Alibaba Group Holding Ltd.
+ *
+ * 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.
+ */
+package com.alibaba.druid.sql.dialect.db2.ast.stmt;
+
+import com.alibaba.druid.sql.ast.statement.SQLSelectQueryBlock;
+
+public class DB2SelectQueryBlock extends SQLSelectQueryBlock {
+
+    private static final long serialVersionUID = 1L;
+
+
+}

src/main/java/com/alibaba/druid/sql/dialect/db2/parser/DB2ExprParser.java

@@ -0,0 +1,20 @@
+package com.alibaba.druid.sql.dialect.db2.parser;
+
+import com.alibaba.druid.sql.parser.Lexer;
+import com.alibaba.druid.sql.parser.SQLExprParser;
+
+public class DB2ExprParser extends SQLExprParser {
+
+    public final static String[] AGGREGATE_FUNCTIONS = { "AVG", "COUNT", "MAX", "MIN", "STDDEV", "SUM", "ROW_NUMBER" };
+
+    public DB2ExprParser(String sql){
+        this(new DB2Lexer(sql));
+        this.lexer.nextToken();
+    }
+
+    public DB2ExprParser(Lexer lexer){
+        super(lexer);
+        this.aggregateFunctions = AGGREGATE_FUNCTIONS;
+    }
+
+}

src/main/java/com/alibaba/druid/sql/dialect/db2/parser/DB2Lexer.java

@@ -0,0 +1,27 @@
+package com.alibaba.druid.sql.dialect.db2.parser;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import com.alibaba.druid.sql.parser.Keywords;
+import com.alibaba.druid.sql.parser.Lexer;
+import com.alibaba.druid.sql.parser.Token;
+
+
+public class DB2Lexer extends Lexer {
+
+    public final static Keywords DEFAULT_DB2_KEYWORDS;
+
+    static {
+        Map<String, Token> map = new HashMap<String, Token>();
+
+        map.putAll(Keywords.DEFAULT_KEYWORDS.getKeywords());
+
+        DEFAULT_DB2_KEYWORDS = new Keywords(map);
+    }
+
+    public DB2Lexer(String input){
+        super(input);
+        super.keywods = DEFAULT_DB2_KEYWORDS;
+    }
+}

src/main/java/com/alibaba/druid/sql/dialect/db2/parser/DB2SelectParser.java

@@ -0,0 +1,80 @@
+/*
+ * Copyright 1999-2011 Alibaba Group Holding Ltd.
+ *
+ * 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.
+ */
+package com.alibaba.druid.sql.dialect.db2.parser;
+
+import com.alibaba.druid.sql.ast.SQLSetQuantifier;
+import com.alibaba.druid.sql.ast.statement.SQLSelectQuery;
+import com.alibaba.druid.sql.ast.statement.SQLSelectQueryBlock;
+import com.alibaba.druid.sql.dialect.db2.ast.stmt.DB2SelectQueryBlock;
+import com.alibaba.druid.sql.parser.SQLExprParser;
+import com.alibaba.druid.sql.parser.SQLSelectParser;
+import com.alibaba.druid.sql.parser.Token;
+
+public class DB2SelectParser extends SQLSelectParser {
+
+    public DB2SelectParser(SQLExprParser exprParser){
+        super(exprParser);
+    }
+
+    public DB2SelectParser(String sql){
+        this(new DB2ExprParser(sql));
+    }
+
+    protected SQLExprParser createExprParser() {
+        return new DB2ExprParser(lexer);
+    }
+
+    @Override
+    public SQLSelectQuery query() {
+        if (lexer.token() == Token.LPAREN) {
+            lexer.nextToken();
+
+            SQLSelectQuery select = query();
+            accept(Token.RPAREN);
+
+            return queryRest(select);
+        }
+
+        accept(Token.SELECT);
+
+        if (lexer.token() == Token.COMMENT) {
+            lexer.nextToken();
+        }
+
+        DB2SelectQueryBlock queryBlock = new DB2SelectQueryBlock();
+
+        if (lexer.token() == Token.DISTINCT) {
+            queryBlock.setDistionOption(SQLSetQuantifier.DISTINCT);
+            lexer.nextToken();
+        } else if (lexer.token() == Token.UNIQUE) {
+            queryBlock.setDistionOption(SQLSetQuantifier.UNIQUE);
+            lexer.nextToken();
+        } else if (lexer.token() == Token.ALL) {
+            queryBlock.setDistionOption(SQLSetQuantifier.ALL);
+            lexer.nextToken();
+        }
+
+        parseSelectList(queryBlock);
+
+        parseFrom(queryBlock);
+
+        parseWhere(queryBlock);
+
+        parseGroupBy(queryBlock);
+
+        return queryRest(queryBlock);
+    }
+}

src/main/java/com/alibaba/druid/sql/dialect/db2/parser/DB2StatementParser.java

@@ -0,0 +1,19 @@
+package com.alibaba.druid.sql.dialect.db2.parser;
+
+import com.alibaba.druid.sql.parser.Lexer;
+import com.alibaba.druid.sql.parser.SQLStatementParser;
+
+
+public class DB2StatementParser extends SQLStatementParser {
+    public DB2StatementParser(String sql) {
+        super (new DB2ExprParser(sql));
+    }
+
+    public DB2StatementParser(Lexer lexer){
+        super(new DB2ExprParser(lexer));
+    }
+
+    public DB2SelectParser createSQLSelectParser() {
+        return new DB2SelectParser(this.exprParser);
+    }
+}

src/main/java/com/alibaba/druid/sql/dialect/db2/visitor/DB2ASTVisitor.java

@@ -0,0 +1,8 @@
+package com.alibaba.druid.sql.dialect.db2.visitor;
+
+import com.alibaba.druid.sql.visitor.SQLASTVisitor;
+
+
+public interface DB2ASTVisitor extends SQLASTVisitor {
+
+}

src/main/java/com/alibaba/druid/sql/dialect/db2/visitor/DB2ASTVisitorAdapter.java

@@ -0,0 +1,7 @@
+package com.alibaba.druid.sql.dialect.db2.visitor;
+
+import com.alibaba.druid.sql.visitor.SQLASTVisitorAdapter;
+
+public class DB2ASTVisitorAdapter extends SQLASTVisitorAdapter implements DB2ASTVisitor {
+
+}