搬砖笔记(二)

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:

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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:

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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:

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<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:

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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:
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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:
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#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:
在这里插入图片描述
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:

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#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:
在这里插入图片描述
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:

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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:
在这里插入图片描述
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:
在这里插入图片描述
需要在浏览器的header中对中文重新进行编码:

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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:

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<!-- 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:

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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;
}
}
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