搬砖笔记(二)

---

title: 搬砖笔记(二)
date: 2019-11-03 14:13:05
updated: 2019-11-03 14:13:05
categories:

• 搬砖笔记
• java

tags:

• java
• jquery
• mybatis
• POI
• spring

---

搬砖笔记(二)

作为码农平时搜集一些小知识点个人认为是个不错的习惯，书上说

好记性不如烂笔头

我想即使是以前忽略或者新get的很简单的东西，自己动手记下来不管如何印象也会更深刻。

这篇笔记截至时间2019年11月3日。

1、jQuery常用的选择器整理
$(":first");//匹配第一个元素
$(":last");//匹配最后一个元素
$(":eq(index)");//在匹配的集合中选择索引值为index的元素
$(":gt(index)");//在匹配的集合中选择索引值大于index的元素
$(":even");//选择索引值为偶数的元素，从0开始计数
$(":odd");//选择索引值为奇数的元素，从0开始计数
$(“parent>child”);//子选择器：选择所有指定"parent"元素中指定的"child"的直接子元素
$(“ancestor decendant”);//后代选择器：选择给定的祖先元素的所有后代元素,一个元素的后代可能是该元素的一个孩子，孙子，曾孙等
$(“prev +next”);//相邻兄弟选择器：选择所有紧接在"prev"元素后的"next"元素
$(“prev ~sibings”);//一般兄弟选择器：匹配"prev"元素之后的所有兄弟元素

2、mybatis批量更新
sql列子：

UPDATE course
    SET name = CASE id 
        WHEN 1 THEN 'name1'
        WHEN 2 THEN 'name2'
        WHEN 3 THEN 'name3'
    END, 
    title = CASE id 
        WHEN 1 THEN 'New Title 1'
        WHEN 2 THEN 'New Title 2'
        WHEN 3 THEN 'New Title 3'
    END
WHERE id IN (1,2,3)

在做编辑订单功能(现在想想都是一场噩梦)时，折腾了这个操作，java代码如下：

int updateBatch(@Param("detailList")List<ThOrderDetail> detailList);

注：myBatis默认会把所有集合封装为"list"，如果要自定义参数名需要用@Param注解

mybatis代码如下：

<update id="updateBatch" parameterType="java.util.List">
    update th_order_detail
    <trim prefix="set" suffixOverrides=",">
      <trim prefix="unit_price =case" suffix="end,">
        <foreach collection="detailList" item="item" index="index">
          <if test="item.unitPrice !=null">
            when ord_detail_id=#{item.ordDetailId} then #{item.unitPrice}
          </if>
          <if test="item.unitPrice == null">
            when ord_detail_id=#{item.ordDetailId} then th_order_detail.unit_price
          </if>
        </foreach>
      </trim>
      <trim prefix="negative_interval_percentage =case" suffix="end,">
        <foreach collection="detailList" item="item" index="index">
          <if test="item.negativeIntervalPercentage !=null">
            when ord_detail_id=#{item.ordDetailId} then #{item.negativeIntervalPercentage}
          </if>
          <if test="item.negativeIntervalPercentage == null">
            when ord_detail_id=#{item.ordDetailId} then th_order_detail.negative_interval_percentage
          </if>
        </foreach>
      </trim>
      <trim prefix="positive_interval_percentage =case" suffix="end,">
        <foreach collection="detailList" item="item" index="index">
          <if test="item.positiveIntervalPercentage !=null">
            when ord_detail_id=#{item.ordDetailId} then #{item.positiveIntervalPercentage}
          </if>
          <if test="item.positiveIntervalPercentage == null">
            when ord_detail_id=#{item.ordDetailId} then th_order_detail.positive_interval_percentage
          </if>
        </foreach>
      </trim>
      <trim prefix="negative_interval_quantity =case" suffix="end,">
        <foreach collection="detailList" item="item" index="index">
          <if test="item.negativeIntervalQuantity !=null">
            when ord_detail_id=#{item.ordDetailId} then #{item.negativeIntervalQuantity}
          </if>
          <if test="item.negativeIntervalQuantity == null">
            when ord_detail_id=#{item.ordDetailId} then th_order_detail.negative_interval_quantity
          </if>
        </foreach>
      </trim>
      <trim prefix="positive_interval_quantity =case" suffix="end,">
        <foreach collection="detailList" item="item" index="index">
          <if test="item.positiveIntervalQuantity !=null">
            when ord_detail_id=#{item.ordDetailId} then #{item.positiveIntervalQuantity}
          </if>
          <if test="item.positiveIntervalQuantity == null">
            when ord_detail_id=#{item.ordDetailId} then th_order_detail.positive_interval_quantity
          </if>
        </foreach>
      </trim>
    </trim>
    where ord_detail_id in
    <foreach collection="detailList" index="index" item="item" separator="," open="(" close=")">
      #{item.ordDetailId}
    </foreach>
  </update>

执行代码后，打印出的sql如下：

update 
  th_order_detail 
set
  unit_price = 
  case
    when ord_detail_id = 252 
    then 25.55 
    when ord_detail_id = 253 
    then 35.55 
  end,
  order_price = 
  case
    when ord_detail_id = 252 
    then 383.25 
    when ord_detail_id = 253 
    then 639.9 
  end,
  negative_interval_percentage = 
  case
    when ord_detail_id = 252 
    then 11.11 
    when ord_detail_id = 253 
    then 13.33 
  end,
  positive_interval_percentage = 
  case
    when ord_detail_id = 252 
    then 12.2 
    when ord_detail_id = 253 
    then 14.44 
  end,
  negative_interval_quantity = 
  case
    when ord_detail_id = 252 
    then 13.3335 
    when ord_detail_id = 253 
    then 15.6006 
  end,
  positive_interval_quantity = 
  case
    when ord_detail_id = 252 
    then 16.83 
    when ord_detail_id = 253 
    then 20.5992 
  end 
where ord_detail_id in (252, 253) ; 

参考链接

3、POI导出Excel

• 测试方法：

public static void main(String[] args) throws IOException {
		HSSFWorkbook workbook = new HSSFWorkbook();

		HSSFCellStyle style = workbook.createCellStyle();
		style.setAlignment(HSSFCellStyle.ALIGN_CENTER);
		style.setVerticalAlignment(HSSFCellStyle.VERTICAL_CENTER);

		HSSFSheet sheet = workbook.createSheet("sheet");

		HSSFRow row0 = sheet.createRow(0);
		HSSFCell cell_00 = row0.createCell(0);
		cell_00.setCellStyle(style);
		cell_00.setCellValue("日期");
		HSSFCell cell_01 = row0.createCell(1);
		cell_01.setCellStyle(style);
		cell_01.setCellValue("午别");

		HSSFRow row1 = sheet.createRow(1);
		HSSFCell cell_10 = row1.createCell(0);
		cell_10.setCellStyle(style);
		cell_10.setCellValue("20191103");
		HSSFCell cell_11 = row1.createCell(1);
		cell_11.setCellStyle(style);
		cell_11.setCellValue("上午");

		HSSFRow row2 = sheet.createRow(2);
		HSSFCell cell_21 = row2.createCell(1);
		cell_21.setCellStyle(style);
		cell_21.setCellValue("下午");

		// 合并日期占两行(4个参数，分别为起始行，结束行，起始列，结束列)
		// 行和列都是从0开始计数，且起始结束都会合并
		// 这里是合并excel中日期的两行为一行
		CellRangeAddress region = new CellRangeAddress(1, 2, 0, 0);
		sheet.addMergedRegion(region);

		File file = new File("E:\\demo.xls");
		FileOutputStream fout = new FileOutputStream(file);
		workbook.write(fout);
		fout.close();
	}

实现效果如下：

日期	午别
20191103	上午
	下午

参考链接

• 项目中导出xcel例子：
  客户给出的表格需要统计对上游付款总金额和对下游付款总金额(大于的为占用金额),然后根据这个占用金额去计算利息
  有两个要求：1、第一行需要显示用款和付款 2、后面如果日期相同也要显示到同一行
  这个用sql查询出来后还需要java代码处理，总之这是今年做的最坑的需求之一(搞死开发者却不一定实用)。
  后台打印出的sql如下：

#分组前sql
select 
    * 
  from
    (
      (select 
        p.amount as amount,
        ifnull(p.payment_date, p.add_time) as payment_date,
        p.contract_id as contract_id,
        c.type as type 
      from
        payment_bond p 
        inner join contract c 
          on p.contract_id = c.contract_id 
          and p.state != 2 
          and c.type in (1, 2) 
          and p.entrust_id = 116) 
      union
      all 
      (select 
        s.amount as amount,
        ifnull(s.payment_date, s.add_time) as payment_date,
        s.contract_id as contract_id,
        c.type as type 
      from
        settlement_apply s 
        inner join contract c 
          on s.contract_id = c.contract_id 
          and s.status in (0, 1, 3) 
          and c.type in (1, 2) 
          and s.entrust_id = 116)
    ) b 
  order by b.payment_date asc

分组前数据库返回结果:

类型为1是采购合同，也就是对上游付款的信息，类型为2的是销售合同，也就是对下游收款的数据。可以看出同一类型同一天的数据还没有合并起来。所以还需要对这个查询结果再分组求和，sql如下：

#分组后sql
select 
  sum(amount) as amount,
  payment_date,
  type 
from
  (上面的sql) bb 
  group by bb.payment_date,bb.type ;

分组后数据库返回结果:

费了九牛二虎之力然而仅仅是开始，在java代码中还需要实现[1、第一行需要显示用款和付款 2、后面如果日期相同也要显示到同一行]这两个要求。大致思路是先定义一些全局的变量来记录上一条数据和第一条数据，找到第一条后再去看后面是不是有时间相同的，controller的核心代码如下：

if(!ObjectUtils.isNullObj(paymentBondViewVos)){
	//百分比
	NumberFormat numFormat = java.text.NumberFormat.getPercentInstance();
	numFormat.setMaximumIntegerDigits(3);
	numFormat.setMaximumFractionDigits(2);
	double payAmount = 0d;//支出金额
	double receiptAmout = 0d;//收入金额
	int type=0;//上一次合同类型(是否第一次)
	boolean alreadySet=false;//已找到第一条
	int lastType=0;//上一次合同类型(循环后)
	Date lastDate=null;//上一次日期
	double lastAmout=0.0;//上一次金额
	int size = paymentBondViewVos.size();
	for(int i = 0; i < size; i++){
		PaymentBondViewVo paymentBondViewVo = paymentBondViewVos.get(i);
		int typeTmp = paymentBondViewVo.getType();//当前合同类型
		if(i==0){
			type = typeTmp;
			row = sheet.createRow(4);
			if(typeTmp==1){
				row.createCell(0).setCellValue(sdf.format(paymentBondViewVo.getPaymentDate()));
				row.createCell(1).setCellValue(paymentBondViewVo.getAmount());
				payAmount = DoubleUtil.preciseAdd(payAmount, paymentBondViewVo.getAmount(), 2);
			}
			if(typeTmp==2){
				row.createCell(2).setCellValue(sdf.format(paymentBondViewVo.getPaymentDate()));
				row.createCell(3).setCellValue(paymentBondViewVo.getAmount());
				receiptAmout = DoubleUtil.preciseAdd(receiptAmout, paymentBondViewVo.getAmount(), 2);
			}
		}else{
			   Date paymentDate = paymentBondViewVo.getPaymentDate();
			   //占用天数
			   int daysOfUse = 0;
				if(type!=typeTmp&&alreadySet==false){//第一条数据展示
					alreadySet=true;
					row = sheet.getRow(4);
					if(typeTmp==2){//采购商后付款
						daysOfUse = daysBetween(lastDate,paymentDate);
					}
				}else if(ObjectUtils.equals(sdf.format(lastDate),sdf.format(paymentDate))){//时间相同的合并到一列
					int lastRowNum = sheet.getLastRowNum();
					row = sheet.getRow(lastRowNum);
					//获取excel上一行的时间并计算占用天数
					daysOfUse = calculateDaysOfUse(sheet,lastRowNum-1,sdf,paymentDate);
				}else{//正常处理
					int lastRowNum = sheet.getLastRowNum();
					row = sheet.createRow(lastRowNum+1);
					//获取excel上一行的时间并计算占用天数
					daysOfUse = calculateDaysOfUse(sheet,lastRowNum,sdf,paymentDate);
				}
				if(typeTmp==1){
					row.createCell(0).setCellValue(sdf.format(paymentDate));
					row.createCell(1).setCellValue(paymentBondViewVo.getAmount());
					payAmount = DoubleUtil.preciseAdd(payAmount, paymentBondViewVo.getAmount(), 2);
				}
				if(typeTmp==2){
					row.createCell(2).setCellValue(sdf.format(paymentDate));
					row.createCell(3).setCellValue(paymentBondViewVo.getAmount());
					receiptAmout = DoubleUtil.preciseAdd(receiptAmout, paymentBondViewVo.getAmount(), 2);
				}
				//支出金额大于收入金额
				if(Double.compare(payAmount, receiptAmout)==1){
					double advancePayment = DoubleUtil.preciseSub(payAmount,receiptAmout, 2);
					//利息=占用金额*占用天数*年化/应付利息天数
					double tmp = DoubleUtil.preciseMul(DoubleUtil.preciseMul(advancePayment,Constant.ANNUALIZED),Double.valueOf(daysOfUse));
					double interestAmount = DoubleUtil.preciseDev(tmp,Double.valueOf(Constant.INTERESTDAYS));

					row.createCell(4).setCellValue(advancePayment);
					row.createCell(5).setCellValue(daysOfUse);
					row.createCell(7).setCellValue(interestAmount);
				}
		}
		row.createCell(6).setCellValue(numFormat.format(Constant.ANNUALIZED));//年化
		lastType=paymentBondViewVo.getType();//上一次合同类型(循环后)
		lastDate=paymentBondViewVo.getPaymentDate();//上一次日期
		lastAmout=paymentBondViewVo.getAmount();//上一次金额
	}
}

只贴出了封装数据代码 (省略查询委托 合同 设置表头 合并单元格以及循环设置单元格样式等代码)。这样以后就导出需要的表格了，效果图如下：

然而作死把浏览器设置为英文后出现文件名乱码了，如下所示：

需要在浏览器的header中对中文重新进行编码：

String codedFileName = java.net.URLEncoder.encode(fileName, "UTF-8");

这样一来,总算搞定了。。。
4、登录时返回之前的链接
在spring中做如下配置：

<!-- 记录登录返回路径 -->
<mvc:interceptor>
    <mvc:mapping path="/mcmall/**"/>
    <mvc:mapping path="/foodmall/**"/>
    <bean class="com.itonghui.filter.RecordLoginInterceptor"/>
</mvc:interceptor>

java代码如下：

public class RecordLoginInterceptor extends HandlerInterceptorAdapter {
	private static final Logger LOGGER = LoggerFactory.getLogger(RecordLoginInterceptor.class);

	/**
	 * 如果返回true 执行下一个拦截器,直到所有的拦截器都执行完毕 再执行被拦截的Controller 然后进入拦截器链
	 */
	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler){
		SysUser user = (SysUser) SecurityUtils.getSubject().getPrincipal();
        String url = "";
        if ((request.getMethod().equalsIgnoreCase(WebContentGenerator.METHOD_POST) || ServerInfo.isAjaxs(request))) {
          return true;
        }else{
            url = request.getRequestURI();
           String queryString =request.getQueryString();
           if(StringUtils.isNotBlank(queryString)){
               url =url+"?"+queryString;
           }
        }
        if(!ObjectUtils.isNullObj(user)){//已登录
            return true;
        }
        HttpSession session = request.getSession();
        session.setAttribute(Constant.HISTORY_URL,url);
        return true;
	}
}