Mybatis 动态组装查询条件，仿SQL模式

目的： 以前比较习惯使用Hibernate，后来觉得mybatis不能按我想要的自动组装为SQL查询条件，所以提供该工具类；

效果图：

 

如图所示，根据条件自动组装查询条件，下面来说一下实现方法：

1. ServiceImpl书写注意项

        Page resultPage = null;
        try {
            PageHelper.startPage(pager.getCurrentPage(), pager.getPageSize());
            // 判断是否有分页
            if (ObjectHelper.isNotEmpty(pager.getDirection())
                    && ObjectHelper.isNotEmpty(pager.getProperties())) {
                specification.addOrderBy(pager.getProperties(),
                        pager.getDirection());
            }
            // 判断是否存在逻辑删除筛选
            String sqlStr = specification.sql();
            if (sqlStr.indexOf("deleted") == -1) {
                specification.eq("deleted", "0");
            }
            resultPage = this.sysLoginMapper.page(specification.sql());
        } catch (Exception e) {
            result = Result.newFailure("数据错误", "在获取分页列表时发生异常。");
            log.error(SimpleLogFormater.formatException(result.getMessage(), e));
            return result;
        }

2. Mapper.java 书写，查询条件非Map对象，直接就是SQL语句了；

    /**
     * 分页查询数据
     * 
     * @return
     */
    Page page(String sqlStr);

3. 关于XML的配置，会拼装SQL语句

 

附：SQL拼装工具类

/** 
 * @Description: (用一句话描述该文件做什么) 
 * @author heliang 
 * @date 2018-7-6 下午6:43:42 
 * @version V2.1 
 */

package com.onem2.base.common;

import com.onem2.base.helper.ObjectHelper;

/**
 * @ClassName: Specification
 * @Description: (这里用一句话描述这个类的作用)
 * @author heliang
 * @date 2018-7-6 下午6:43:42
 * @version V2.1 * Update Logs: * Name: * Date: * Description: 初始化
 */

public class Specification {

    private StringBuilder where = new StringBuilder();
    private String groupBy;
    private String having;
    private String orderBy;

    public StringBuilder getWhere() {
        return where;
    }

    public void setWhere(StringBuilder where) {
        this.where = where;
    }

    public String getGroupBy() {
        return groupBy;
    }

    public void setGroupBy(String groupBy) {
        this.groupBy = groupBy;
    }

    public String getHaving() {
        return having;
    }

    public void setHaving(String having) {
        this.having = having;
    }

    public String getOrderBy() {
        return orderBy;
    }

    public void setOrderBy(String orderBy) {
        this.orderBy = orderBy;
    }

    public Specification addOrderBy(String sort, String order) {
        if (!isEmpty(sort) && !isEmpty(order)) {
            this.orderBy = ObjectHelper.underscoreName(sort) + " " + order;
        }
        return this;
    }

    public Specification orLike(String value, String columns) {
        if (!isEmpty(value)) {
            StringBuffer strBuf = new StringBuffer("");
            for (String column : columns.split(",")) {
                strBuf.append(ObjectHelper.underscoreName(column) + " like '%"
                        + value + "%' or ");
            }
            String orLikeStr = strBuf.substring(0, strBuf.lastIndexOf("or"));
            where.append(" and (" + orLikeStr + ")");
        }
        return this;
    }

    public Specification eq(String column, String value) {
        if (!isEmpty(value)) {
            where.append(" and " + ObjectHelper.underscoreName(column) + " = '"
                    + sqlParam(value) + "'");
        }
        return this;
    }

    public Specification ne(String column, String value) {
        if (!isEmpty(value)) {
            where.append(" and " + ObjectHelper.underscoreName(column)
                    + " != '" + sqlParam(value) + "'");
        }
        return this;
    }

    public Specification like(String column, String value) {
        if (!isEmpty(value)) {
            where.append(" and " + ObjectHelper.underscoreName(column)
                    + " like '%" + sqlParam(value) + "%'");
        }
        return this;
    }

    public Specification notLike(String column, String value) {
        if (!isEmpty(value)) {
            where.append(" and " + ObjectHelper.underscoreName(column)
                    + " not like '%" + sqlParam(value) + "%'");
        }
        return this;
    }

    public Specification in(String column, String... values) {
        if (!isEmpty(values)) {
            where.append(" and " + ObjectHelper.underscoreName(column)
                    + " in (" + inValuesString(values) + ")");
        }
        return this;
    }

    public Specification notIn(String column, String... values) {
        if (!isEmpty(values)) {
            where.append(" and " + ObjectHelper.underscoreName(column)
                    + " not in (" + inValuesString(values) + ")");
        }
        return this;
    }

    public Specification gt(String column, String value) {
        if (!isEmpty(value)) {
            where.append(" and " + ObjectHelper.underscoreName(column) + " > '"
                    + sqlParam(value) + "'");
        }
        return this;
    }

    public Specification gte(String column, String value) {
        if (!isEmpty(value)) {
            where.append(" and " + ObjectHelper.underscoreName(column)
                    + " >= '" + sqlParam(value) + "'");
        }
        return this;
    }

    public Specification lt(String column, String value) {
        if (!isEmpty(value)) {
            where.append(" and " + ObjectHelper.underscoreName(column) + " < '"
                    + sqlParam(value) + "'");
        }
        return this;
    }

    public Specification lte(String column, String value) {
        if (!isEmpty(value)) {
            where.append(" and " + ObjectHelper.underscoreName(column)
                    + " <= '" + sqlParam(value) + "'");
        }
        return this;
    }

    public Specification between(String column, String from, String to) {
        if (isEmpty(from) && isEmpty(to)) {
            return this;
        }
        if (isEmpty(to)) {
            where.append(" and " + ObjectHelper.underscoreName(column)
                    + " >= '" + sqlParam(from) + "'");
        } else if (isEmpty(from)) {
            where.append(" and " + ObjectHelper.underscoreName(column)
                    + " <= '" + sqlParam(to) + "'");
        } else {
            where.append(" and " + ObjectHelper.underscoreName(column)
                    + " between '" + sqlParam(from) + "' and '" + sqlParam(to)
                    + "'");
        }
        return this;
    }

    public String sql() {
        StringBuilder sql = new StringBuilder("");
        final int a = 4;
        final int b = 5;
        if (where.length() > a) {
            sql.append(" " + where.substring(b));
        }
        if (!isEmpty(groupBy)) {
            sql.append(" group by " + groupBy);
        }
        if (!isEmpty(having)) {
            sql.append(" having " + having);
        }
        if (!isEmpty(orderBy)) {
            sql.append(" order by " + orderBy);
        }
        return sql.toString();
    }

    public String toString() {
        return sql();
    }

    private static boolean isEmpty(String value) {
        return value == null || "".equals(value) || value.trim().length() == 0;
    }

    private static boolean isEmpty(String[] values) {
        if (values == null || values.length == 0) {
            return true;
        }
        for (String value : values) {
            if (!isEmpty(value)) {
                return false;
            }
        }
        return true;
    }

    private static String inValuesString(String[] values) {
        StringBuilder string = new StringBuilder();
        for (String value : values) {
            if (isEmpty(value)) {
                continue;
            }
            string.append('\'');
            string.append(value);
            string.append('\'');
            string.append(',');
        }
        if (string.length() > 0) {
            string.deleteCharAt(string.length() - 1);
        }
        return string.toString();
    }

    private static String sqlParam(String sqlParam) {
        return sqlParam.replaceAll("([';]+|(--)+)", "");
    }
}

附：ObjectHelper 工具源码:

package com.onem2.base.helper;

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

/**
 * Object帮助类 功能：此类提供处理