org.fastquery.core.RegexCache Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of fastquery Show documentation
Method of fast database query in complicated environment.
The newest version!
/*
 * Copyright (c) 2016-2088, fastquery.org and/or its affiliates. All rights reserved.
 *
 * 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.
 *
 * For more information, please see http://www.fastquery.org/.
 *
 */

package org.fastquery.core;

import lombok.extern.slf4j.Slf4j;

import java.util.HashMap;
import java.util.Map;
import java.util.regex.Pattern;

/**
 * 正则编译缓存
 *
 * @author xixifeng ([email protected])
 */
@Slf4j
public final class RegexCache
{

    private RegexCache()
    {
        throw new IllegalStateException("Placeholder is Utility class");
    }

    public static final Pattern MOR_BLANK_PATT = Pattern.compile("\\s+");

    static final Pattern TABLE_REG_PATT = Pattern.compile("#\\{#table}");

    static final Pattern ID_REG_PATT = Pattern.compile("#\\{#id}");

    public static final Pattern SETS_REG_PATT = Pattern.compile("#\\{#sets}");
    public static final Pattern WHERE_REG_PATT = Pattern.compile("#\\{#where}");

    public static final Pattern LIMIT_RGE_PATT = Pattern.compile("#\\{#limit}");

    public static final Pattern SP1_REG_PATT = Pattern.compile("\\?\\d+");


    /**
     * 搜索出"?"后面的数字
     */
    public static final Pattern SEARCH_NUM_PATT = Pattern.compile("(?<=\\?)\\d+");

    /**
     * 匹配冒号表达式
     */
    public static final Pattern COLON_REG_PATT = Pattern.compile(":+[A-Za-z0-9]+");

    /**
     * 匹配EL表达式,可能包含有_ . ( ) 如: 在模板中调用 ${_method.getString()}
     */
    public static final Pattern EL_REG_PATT = Pattern.compile("\\$\\{?[A-Za-z0-9_.()]+}?");

    /**
     * 匹配EL表达式或匹配冒号表达式
     */
    public static final Pattern EL_OR_COLON_PATT = Pattern.compile("\\$\\{?[A-Za-z0-9_.()]+}?|:+[A-Za-z0-9]+");

    private static final Map patterns = new HashMap<>();

    private static synchronized Pattern put(String regex)
    {
        Pattern pattern = Pattern.compile(regex);
        // 调用 Map.put 返回是当前 put 之前，根据 key 获取的 val
        // 那么，一个 key 第一次 put 后，必然返回 null
        patterns.put(regex, pattern);
        return pattern;
    }

    public static Pattern getPattern(String regex)
    {
        Pattern pattern = patterns.get(regex);
        if (pattern != null)
        {
            return pattern;
        }
        else
        {
            return put(regex);
        }
    }
}