com.baomidou.mybatisplus.extension.kotlin.AbstractKtWrapper.kt Maven / Gradle / Ivy

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/*
 * Copyright (c) 2011-2022, baomidou ([email protected]).
 *
 * 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.baomidou.mybatisplus.extension.kotlin

import com.baomidou.mybatisplus.core.conditions.AbstractWrapper
import com.baomidou.mybatisplus.core.toolkit.LambdaUtils
import com.baomidou.mybatisplus.core.toolkit.StringPool
import com.baomidou.mybatisplus.core.toolkit.support.ColumnCache
import kotlin.reflect.KProperty

/**
 * Lambda 语法使用 Wrapper
 *
 * 统一处理解析 lambda 获取 column
 *
 * @author yangyuhan,MieMie,HanChunLin
 * @since 2018-11-07
 */
abstract class AbstractKtWrapper> : AbstractWrapper, Children>() {

    /**
     * 列 Map
     */
    protected lateinit var columnMap: Map

    /**
     * 重载方法，默认 onlyColumn = true
     */
    override fun columnToString(kProperty: KProperty<*>): String? = columnToString(kProperty, true)

    /**
     * 核心实现方法，供重载使用
     */
    private fun columnToString(kProperty: KProperty<*>, onlyColumn: Boolean): String? {
        return columnMap[LambdaUtils.formatKey(kProperty.name)]?.let { if (onlyColumn) it.column else it.columnSelect }
    }

    /**
     * 批量处理传入的属性，正常情况下的输出就像：
     *
     * "user_id" AS "userId" , "user_name" AS "userName"
     */
    fun columnsToString(onlyColumn: Boolean, vararg columns: KProperty<*>): String =
        columns.mapNotNull { columnToString(it, onlyColumn) }.joinToString(separator = StringPool.COMMA)

    override fun initNeed() {
        super.initNeed()
        if (!::columnMap.isInitialized) {
            columnMap = LambdaUtils.getColumnMap(this.entityClass)
        }
    }
}