| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.flink.table.client.cli; |
| |
| import java.util.Arrays; |
| import java.util.Objects; |
| import java.util.Optional; |
| import java.util.function.Function; |
| import java.util.regex.Matcher; |
| import java.util.regex.Pattern; |
| |
| /** |
| * Simple parser for determining the type of command and its parameters. |
| */ |
| public final class SqlCommandParser { |
| |
| private SqlCommandParser() { |
| // private |
| } |
| |
| public static Optional<SqlCommandCall> parse(String stmt) { |
| // normalize |
| stmt = stmt.trim(); |
| // remove ';' at the end |
| if (stmt.endsWith(";")) { |
| stmt = stmt.substring(0, stmt.length() - 1).trim(); |
| } |
| |
| // parse |
| for (SqlCommand cmd : SqlCommand.values()) { |
| final Matcher matcher = cmd.pattern.matcher(stmt); |
| if (matcher.matches()) { |
| final String[] groups = new String[matcher.groupCount()]; |
| for (int i = 0; i < groups.length; i++) { |
| groups[i] = matcher.group(i + 1); |
| } |
| return cmd.operandConverter.apply(groups) |
| .map((operands) -> new SqlCommandCall(cmd, operands)); |
| } |
| } |
| return Optional.empty(); |
| } |
| |
| // -------------------------------------------------------------------------------------------- |
| |
| private static final Function<String[], Optional<String[]>> NO_OPERANDS = |
| (operands) -> Optional.of(new String[0]); |
| |
| private static final Function<String[], Optional<String[]>> SINGLE_OPERAND = |
| (operands) -> Optional.of(new String[]{operands[0]}); |
| |
| private static final int DEFAULT_PATTERN_FLAGS = Pattern.CASE_INSENSITIVE | Pattern.DOTALL; |
| |
| /** |
| * Supported SQL commands. |
| */ |
| enum SqlCommand { |
| QUIT( |
| "(QUIT|EXIT)", |
| NO_OPERANDS), |
| |
| CLEAR( |
| "CLEAR", |
| NO_OPERANDS), |
| |
| HELP( |
| "HELP", |
| NO_OPERANDS), |
| |
| SHOW_CATALOGS( |
| "SHOW\\s+CATALOGS", |
| NO_OPERANDS), |
| |
| SHOW_DATABASES( |
| "SHOW\\s+DATABASES", |
| NO_OPERANDS), |
| |
| SHOW_TABLES( |
| "SHOW\\s+TABLES", |
| NO_OPERANDS), |
| |
| SHOW_FUNCTIONS( |
| "SHOW\\s+FUNCTIONS", |
| NO_OPERANDS), |
| |
| USE( |
| "USE\\s+(.*)", |
| SINGLE_OPERAND), |
| |
| DESCRIBE( |
| "DESCRIBE\\s+(.*)", |
| SINGLE_OPERAND), |
| |
| DESC( |
| "DESC\\s+(.*)", |
| SINGLE_OPERAND), |
| |
| EXPLAIN( |
| "EXPLAIN\\s+(.*)", |
| SINGLE_OPERAND), |
| |
| SELECT( |
| "(SELECT.*)", |
| SINGLE_OPERAND), |
| |
| INSERT_INTO( |
| "(INSERT\\s+INTO.*)", |
| SINGLE_OPERAND), |
| |
| CREATE_TABLE( |
| "(CREATE\\s+TABLE.*)", |
| SINGLE_OPERAND), |
| |
| CREATE_VIEW( |
| "(CREATE\\s+VIEW\\s+(\\S+)\\s+AS\\s+(.*))", |
| (operands) -> { |
| if (operands.length < 3) { |
| return Optional.empty(); |
| } |
| return Optional.of(new String[]{operands[0], operands[1], operands[2]}); |
| }), |
| |
| DROP_VIEW( |
| "DROP\\s+VIEW\\s+(.*)", |
| SINGLE_OPERAND), |
| |
| CREATE_FUNCTION( |
| "(CREATE\\s+FUNCTION.*)", |
| SINGLE_OPERAND), |
| |
| SET( |
| "SET(\\s+(\\S+)\\s*=(.*))?", // whitespace is only ignored on the left side of '=' |
| (operands) -> { |
| if (operands.length < 3) { |
| return Optional.empty(); |
| } else if (operands[0] == null) { |
| return Optional.of(new String[0]); |
| } |
| return Optional.of(new String[]{operands[1], operands[2]}); |
| }), |
| |
| RESET( |
| "RESET", |
| NO_OPERANDS), |
| |
| SOURCE( |
| "SOURCE\\s+(.*)", |
| SINGLE_OPERAND); |
| |
| public final Pattern pattern; |
| public final Function<String[], Optional<String[]>> operandConverter; |
| |
| SqlCommand(String matchingRegex, Function<String[], Optional<String[]>> operandConverter) { |
| this.pattern = Pattern.compile(matchingRegex, DEFAULT_PATTERN_FLAGS); |
| this.operandConverter = operandConverter; |
| } |
| |
| @Override |
| public String toString() { |
| return super.toString().replace('_', ' '); |
| } |
| |
| public boolean hasOperands() { |
| return operandConverter != NO_OPERANDS; |
| } |
| } |
| |
| /** |
| * Call of SQL command with operands and command type. |
| */ |
| public static class SqlCommandCall { |
| public final SqlCommand command; |
| public final String[] operands; |
| |
| public SqlCommandCall(SqlCommand command, String[] operands) { |
| this.command = command; |
| this.operands = operands; |
| } |
| |
| public SqlCommandCall(SqlCommand command) { |
| this(command, new String[0]); |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (this == o) { |
| return true; |
| } |
| if (o == null || getClass() != o.getClass()) { |
| return false; |
| } |
| SqlCommandCall that = (SqlCommandCall) o; |
| return command == that.command && Arrays.equals(operands, that.operands); |
| } |
| |
| @Override |
| public int hashCode() { |
| int result = Objects.hash(command); |
| result = 31 * result + Arrays.hashCode(operands); |
| return result; |
| } |
| |
| @Override |
| public String toString() { |
| return command + "(" + Arrays.toString(operands) + ")"; |
| } |
| } |
| } |