All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.dromara.hutool.db.sql.ConditionBuilder Maven / Gradle / Ivy

Go to download

Hutool是一个优雅而小巧的Java工具类库

There is a newer version: 6.0.0.M3
Show newest version
/*
 * Copyright (c) 2013-2024 Hutool Team and hutool.cn
 *
 * 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 org.dromara.hutool.db.sql;

import org.dromara.hutool.core.lang.builder.Builder;
import org.dromara.hutool.core.collection.ListUtil;
import org.dromara.hutool.core.array.ArrayUtil;
import org.dromara.hutool.core.text.CharUtil;
import org.dromara.hutool.core.text.StrUtil;

import java.util.ArrayList;
import java.util.List;

/**
 * 多条件构建封装

 * 可以将多个条件构建为SQL语句的一部分，并将参数值转换为占位符，并提取对应位置的参数值。

 * 例如：name = ? AND type IN (?, ?) AND other LIKE ?
 *
 * @author looly
 * @since 5.4.3
 */
public class ConditionBuilder implements Builder {
	private static final long serialVersionUID = 1L;

	/**
	 * 创建构建器
	 *
	 * @param conditions 条件列表
	 * @return ConditionBuilder
	 */
	public static ConditionBuilder of(final Condition... conditions) {
		return new ConditionBuilder(conditions);
	}

	/**
	 * 条件数组
	 */
	private final Condition[] conditions;
	/**
	 * 占位符对应的值列表
	 */
	private List paramValues;

	/**
	 * 构造
	 *
	 * @param conditions 条件列表
	 */
	public ConditionBuilder(final Condition... conditions) {
		this.conditions = conditions;
	}

	/**
	 * 返回构建后的参数列表

	 * 此方法调用前必须调用{@link #build()}
	 *
	 * @return 参数列表
	 */
	public List getParamValues() {
		return ListUtil.view(this.paramValues);
	}

	/**
	 * 构建组合条件

	 * 例如：name = ? AND type IN (?, ?) AND other LIKE ?
	 *
	 * @return 构建后的SQL语句条件部分
	 */
	@Override
	public String build() {
		if(null == this.paramValues){
			this.paramValues = new ArrayList<>();
		} else {
			this.paramValues.clear();
		}
		return build(this.paramValues);
	}

	/**
	 * 构建组合条件

	 * 例如：name = ? AND type IN (?, ?) AND other LIKE ?
	 *
	 * @param paramValues 用于写出参数的List,构建时会将参数写入此List
	 * @return 构建后的SQL语句条件部分
	 */
	public String build(final List paramValues) {
		if (ArrayUtil.isEmpty(conditions)) {
			return StrUtil.EMPTY;
		}

		final StringBuilder conditionStrBuilder = new StringBuilder();
		boolean isFirst = true;
		for (final Condition condition : conditions) {
			// 添加逻辑运算符
			if (isFirst) {
				isFirst = false;
			} else {
				// " AND " 或者 " OR "
				conditionStrBuilder.append(CharUtil.SPACE).append(condition.getLinkOperator()).append(CharUtil.SPACE);
			}

			// 构建条件部分："name = ?"、"name IN (?,?,?)"、"name BETWEEN ？AND ？"、"name LIKE ?"
			conditionStrBuilder.append(condition.toString(paramValues));
		}
		return conditionStrBuilder.toString();
	}

	/**
	 * 构建组合条件

	 * 例如：name = ? AND type IN (?, ?) AND other LIKE ?
	 *
	 * @return 构建后的SQL语句条件部分
	 */
	@Override
	public String toString() {
		return build();
	}
}
 















© 2015 - 2024 Weber Informatics LLC | Privacy Policy