/*
* 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.util;
import com.alibaba.druid.sql.parser.Lexer;
import com.dangdang.ddframe.rdb.sharding.exception.SQLParserException;
import com.dangdang.ddframe.rdb.sharding.parser.result.router.SQLStatementType;
import com.google.common.base.CharMatcher;
import lombok.AccessLevel;
import lombok.AllArgsConstructor;
import java.sql.SQLException;
import java.util.Collection;
/**
* SQL工具类.
*
* @author gaohongtao
*/
@AllArgsConstructor(access = AccessLevel.PRIVATE)
public class SQLUtil {
/**
* 去掉SQL表达式的特殊字符.
*
* @param value SQL表达式
* @return 去掉SQL特殊字符的表达式
*/
public static String getExactlyValue(final String value) {
return null == value ? null : CharMatcher.anyOf("[]`'\"").removeFrom(value);
}
/**
* 安全的调用一组可能抛出{@linkplain SQLException}的对象中的方法.
* 通过该方法保证后,保证每个对象中的方法均被调用一次
*
* @param throwableSQLExceptionObjects 调用方法可能抛出异常的对象集合
* @param method 方法定义
* @param <T> 对象类型
* @throws SQLException 数据库访问异常会抛出
*/
public static <T> void safeInvoke(final Collection<T> throwableSQLExceptionObjects, final ThrowableSQLExceptionMethod<T> method) throws SQLException {
SQLException current = null;
for (T each : throwableSQLExceptionObjects) {
try {
method.apply(each);
} catch (final SQLException exp) {
if (null == current) {
current = exp;
} else {
current.setNextException(exp);
current = exp;
}
}
}
if (null != current) {
throw current;
}
}
/**
* 根据SQL第一个单词判断SQL类型.
*
* @param sql SQL语句
* @return SQL类型
*/
public static SQLStatementType getTypeByStart(final String sql) {
//TODO: Use new Lexer Util.
Lexer lexer = new Lexer(sql);
lexer.nextToken();
while (true) {
switch (lexer.token()) {
case SELECT: return SQLStatementType.SELECT;
case INSERT: return SQLStatementType.INSERT;
case UPDATE: return SQLStatementType.UPDATE;
case DELETE: return SQLStatementType.DELETE;
case EOF: throw new SQLParserException("Unsupported SQL statement: [%s]", sql);
default: lexer.nextToken();
}
}
}
}