我要评论分页:limit ?,?
参数1 : startindex 开始索引.
参数2 : pagesize 每页显示的个数
n 表示第几页 给定一个特殊的单词 pagenumber
select * from product;
第一页显示五条数据:
select * from product limit 0 , 5;
第二页显示五条数据
select * from product limit 5 , 5;
第三页显示五条数据
select * from product limit 10 , 5;
第n页显示五条数据
select * from product limit (pagenumber-1)*pagesize , pagesize;
如果只有一个参数 表示 第一页 显示几个数据
select * from product limit 5;
简单分页查询步骤:
1.sql : select from table limit ?,?
2.startintdex : 开始索引 不可以是负数
3.pagesize : 每页显示的个数
4.pagenumber : 用户访问的当前页
5.由页面发起传入 pagenumber 和 pagesize(目前写死) 在service层中进行计算startindex
6.公式 (pagenumber-1)*pagesize
高级分页查询:
将service返回的六个参数,封装成一个pagebean
两个传的
pagenumber,pagesize.
两个查的
totalrecord,data
两个算的
startindex,totalpage
在service编写代码逻辑 --> 将所有的代码逻辑封装到pagebean中
/*
<!--分页 class="disabled" class="active"-->
<div style="width:1100px;margin:0 auto;margin-top:50px;">
<ul class="pagination" style="text-align:center; margin-top:10px;">
<%-- 如果当前页 等于 1 不需要再显示上一页 如果当前不等于1 显示 --%>
<c:if test="${pagebean.pagenumber != 1}">
<li ><a href="${pagecontext.request.contextpath}/productservlet?method=findall&pagenumber=1" aria-label="previous"><span aria-hidden="true">«</span></a></li>
<li ><a href="${pagecontext.request.contextpath}/productservlet?method=findall&pagenumber=${pagebean.pagenumber - 1 }" aria-label="previous"><span aria-hidden="true">上一页</span></a></li>
</c:if>
<%-- 循环显示 所有的页数 --%>
<c:foreach begin="${pagebean.start}" end="${pagebean.end}" var="num" step="1">
<li ${pagebean.pagenumber == num ? " class='active'" : ""} ><a href="${pagecontext.request.contextpath}/productservlet?method=findall&pagenumber=${num}">${num}</a></li>
</c:foreach>
<%-- 如果当前页小于总页数 显示下一页 --%>
<c:if test="${pagebean.pagenumber < pagebean.totalpage}">
<li><a href="${pagecontext.request.contextpath}/productservlet?method=findall&pagenumber=${pagebean.pagenumber + 1 }" aria-label="next"><span aria-hidden="true">下一页</span></a></li>
<li><a href="${pagecontext.request.contextpath}/productservlet?method=findall&pagenumber=${pagebean.totalpage}" aria-label="next"><span aria-hidden="true">»</span></a></li>
</c:if>
</ul>
</div>
<!-- 分页结束======================= -->
以后专门用来处理分页的数据:
泛型的定义:
1:方法级别的定义,修饰和返回值之间<t>
2:类级别泛型定义,类名后<t>
public class pagebean<t> {
/*
一共六个参数:
2个传入:
pagenumber : 表示当前页
pagesize : 表示每页显示个数
2个查询
data : 分页的数据
totalrecord : 总记录数
2个计算
startindex : 开始索引
totalpage : 总页数
private int pagenumber;
private int pagesize;
private int totalrecodr;
private int startindex;
private int totalpage;
private list<t> data;
public int getstartindex() {
startindex = (pagenumber - 1)*pagesize;
}
public int gettotalpage() {
if(totalrecord % pagesize == 0) {
totalpage = totalrecord / pagesize;
}else {
totalpage = totalrecord / pagesize + 1;
}
return totalpage;
}
public int getpagenumber() {
return pagenumber;
}
public void setpagenumber(int pagenumber) {
this.pagenumber = pagenumber;
}
}
开发中真实案例--前五后四动态条 - 扩展 - 前四后五
开发中应用:
//循环的开始
private int start;
//循环结束
private int end;
//计算 开始 和 结束的数据
private void jisuan() {
//总页数有没有可能小于10
//小于 10 不需要前四后五的动态条
if(gettotalpage() < 10) {//必须调用gettotalpage() 因为totalpage需要提前计算
start = 1;
end = totalpage;//最后一页等于最大页数
}else {
//总页数一定大于10 需要前四后五动态条
start = pagenumber - 4;
end = pagenumber + 5;
//如果start < 1 表示 当前1 2 3 4 总共显示10页
if(start < 1) {
start = 1;
end = 10;
}
//如果end > totalpage 需要 计算start值
if(end > totalpage) {
end = totalpage;
start = totalpage - 9;
}
}
}
案例:代码体现
public class productservlet extends httpservlet {
protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {
try {
//获得页面传递的参数 用来执行某段代码
string method = request.getparameter("method");
productservice pservice = new productservice();
categoryservice cservice = new categoryservice();
//根据页面功能执行某段特殊的代码
if("findall".equals(method)){
/**
* 1.类型问题 两种解决方式: 1.正则 2.try
* 2.索引不可以是负数
*/
//1.获得
// 获得分页的数据 pagenumber
string pagenumberstr = request.getparameter("pagenumber");
int pagenumber = 1;
try {
//如果是a 强转失败 赋值操作没有成功 pagenumber = 1
pagenumber = integer.valueof(pagenumberstr);
if(pagenumber < 1 ){
pagenumber = 1;
}
} catch (exception e) {
}
int pagesize = 2;
//2.处理
//list<product> plist = pservice.findbypage(pagenumber , pagesize);
pagebean<product> pagebean = pservice.findbypage(pagenumber , pagesize);
//3.响应
//3.1 将数据存到request
request.setattribute("pagebean", pagebean);
//3.2 请求转发给jsp
request.getrequestdispatcher("/admin/product/product_list.jsp").forward(request, response);
return;
}
//添加商品前查询分类的数据
if("addproductui".equals(method)){
//1.获得
//2.处理
//2.1 调用service 查询出所有分类 返回值 list<category>
list<category> clist = cservice.findall();
//3.响应
//3.1 将数据存到request
request.setattribute("clist", clist);
//3.2 请求转发给product_add.jsp
request.getrequestdispatcher("/admin/product/product_add.jsp").forward(request, response);
return;
}
//添加商品数据
if("addproduct".equals(method)){
//1.获得
//1.1 获得map
map<string, string[]> map = request.getparametermap();
//1.2 创建product
product product = new product();
//1.3 封装数据
beanutils.populate(product, map);
//1.4 手动封装数据
product.setpid( uuid.randomuuid().tostring().replace("-", "") );//主键会随机生成
product.setpimage("products/1/c_0001.jpg");
product.setpdate(new date().tolocalestring());
product.setis_hot(0);//0表示非热门
product.setpflag(0);//0表示未下架
//2.处理
//调用service保存
pservice.save(product);
//3.响应
//重定向到查询所有的案例
response.sendredirect(request.getcontextpath() +"/productservlet?method=findall");
return;
}
//根据pid查询出商品的信息
if("findbypid".equals(method)){
//1.获得
//获得pid的编号
string pid = request.getparameter("pid");
//2 处理
//2.1 商品数据
product product = pservice.findbypid(pid);
//2.2 分类的数据
list<category> clist = cservice.findall();
//3 响应
request.setattribute("product", product);
request.setattribute("clist", clist);
request.getrequestdispatcher("/admin/product/product_edit.jsp").forward(request, response);
return;
}
//修改商品数据的代码
if("editproduct".equals(method)){
//1.获得
//1.1 获得map集合
map<string, string[]> map = request.getparametermap();
//1.2 创建product对象
product product = new product();
//1.3 封装
beanutils.populate(product, map);
//2.处理
//2.1 调用service修改
boolean flag = pservice.update(product);
//3.响应
//3.1 重定向到查询所有的案例
if(flag){
//成功
response.sendredirect(request.getcontextpath() + "/productservlet?method=findall");
}
return ;
}
//根据pid删除商品
if("deletebypid".equals(method)){
//1.获得
//获得pid
string pid = request.getparameter("pid");
//2.处理
int count = pservice.deletebypid(pid);
//3.响应
if(count > 0){
response.sendredirect(request.getcontextpath() + "/productservlet?method=findall");
}
return;
}
} catch (exception e) {
e.printstacktrace();
}
}
protected void dopost(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {
// todo auto-generated method stub
doget(request, response);
}
public static void main(string[] args) {
system.out.println(uuid.randomuuid().tostring().replace("-", ""));
}
}
public class productservice {
/*public pagebean<product> findbypage(int pagenumber, int pagesize) throws sqlexception {
//创建一个即将被返回的对象 pagebean<product>
pagebean<product> pagebean = new pagebean<product>();
productdao dao = new productdao();
//将pagenumber 转换成startindex
int startindex = (pagenumber - 1) * pagesize;
//查询当前页的2条数据
list<product> data = dao.findbypage( startindex, pagesize);
//查询总记录数
int totalrecord = dao.findrecord();
//计算总页数
int totalpage = 0;
if(totalrecord % pagesize == 0 ){
totalpage = totalrecord / pagesize;
}else{
totalpage = totalrecord / pagesize + 1;
}
//赋值
pagebean.setdata(data);
pagebean.setpagenumber(pagenumber);
pagebean.setpagesize(pagesize);
pagebean.setstartindex(startindex);
pagebean.settotalpage(totalpage);
pagebean.settotalrecord(totalrecord);
return pagebean;
}*/
public pagebean<product> findbypage(int pagenumber, int pagesize) throws sqlexception {
//创建一个即将被返回的对象 pagebean<product>
pagebean<product> pagebean = new pagebean<product>( pagenumber , pagesize);
productdao dao = new productdao();
//查询当前页的2条数据
list<product> data = dao.findbypage( pagebean.getstartindex() , pagesize);
//查询总记录数
int totalrecord = dao.findrecord();
//赋值
pagebean.setdata(data);
pagebean.settotalrecord(totalrecord);
return pagebean;
}
public list<product> findall() throws sqlexception {
productdao dao = new productdao();
return dao.findall();
}
public void save(product product) throws sqlexception {
productdao dao = new productdao();
dao.save(product);
}
public product findbypid(string pid) throws sqlexception {
productdao dao = new productdao();
return dao.findbypid(pid);
}
public boolean update(product product) throws sqlexception {
productdao dao = new productdao();
return dao.update(product);
}
public int deletebypid(string pid) throws sqlexception {
productdao dao = new productdao();
return dao.deletebypid(pid);
}
}
package com.baidu.domain;
public class product {
/*
`pid` varchar(32) not null,
`pname` varchar(50) default null, #商品名称
`market_price` double default null, #商场价
`shop_price` double default null, #商城价
`pimage` varchar(200) default null, #商品图片路径
`pdate` date default null, #上架时间
`is_hot` int(11) default null, #是否热门：0=不热门,1=热门
`pdesc` varchar(255) default null, #商品描述
`pflag` int(11) default 0, #商品标记：0=未下架(默认值),1=已经下架
`cid` varchar(32) default null, #分类id*/
private string pid;
private string pname;
private double market_price;
private double shop_price;
private string pimage;
private string pdate;
private int is_hot;
private string pdesc;
private int pflag;
private string cid;
public string getpid() {
return pid;
}
public void setpid(string pid) {
this.pid = pid;
}
public string getpname() {
return pname;
}
public void setpname(string pname) {
this.pname = pname;
}
public double getmarket_price() {
return market_price;
}
public void setmarket_price(double market_price) {
this.market_price = market_price;
}
public double getshop_price() {
return shop_price;
}
public void setshop_price(double shop_price) {
this.shop_price = shop_price;
}
public string getpimage() {
return pimage;
}
public void setpimage(string pimage) {
this.pimage = pimage;
}
public string getpdate() {
return pdate;
}
public void setpdate(string pdate) {
this.pdate = pdate;
}
public int getis_hot() {
return is_hot;
}
public void setis_hot(int is_hot) {
this.is_hot = is_hot;
}
public string getpdesc() {
return pdesc;
}
public void setpdesc(string pdesc) {
this.pdesc = pdesc;
}
public int getpflag() {
return pflag;
}
public void setpflag(int pflag) {
this.pflag = pflag;
}
public string getcid() {
return cid;
}
public void setcid(string cid) {
this.cid = cid;
}
}
public class productdao {
/**
* 分页的dao
* @param startindex
* @param pagesize
* @return
* @throws sqlexception
*/
public list<product> findbypage(int startindex, int pagesize) throws sqlexception {
queryrunner queryrunner = new queryrunner(c3p0utils.getdatasource());
string sql =" select * from product limit ?,? ";
object [] params = {
startindex , pagesize
};
return queryrunner.query(sql, new beanlisthandler<product>(product.class), params);
}
/**
* 计算总记录数
* @return
* @throws sqlexception
*/
public int findrecord() throws sqlexception {
queryrunner queryrunner = new queryrunner(c3p0utils.getdatasource());
string sql =" select count(*) from product ";
object [] params = {
};
object object = queryrunner.query(sql, new scalarhandler(), params);
return integer.valueof(object.tostring());
}
public list<product> findall() throws sqlexception {
queryrunner queryrunner = new queryrunner(c3p0utils.getdatasource());
string sql =" select * from product order by pdate desc ";
object [] params = {};
return queryrunner.query(sql, new beanlisthandler<product>(product.class), params);
}
public void save(product product) throws sqlexception {
queryrunner queryrunner = new queryrunner(c3p0utils.getdatasource());
string sql =" insert into product values(?,?,?,?,?,?,?,?,?,?) ";
object [] params = {
product.getpid() , product.getpname() , product.getmarket_price() ,
product.getshop_price() , product.getpimage() , product.getpdate() ,
product.getis_hot() , product.getpdesc() , product.getpflag() ,
product.getcid()
};
queryrunner.update(sql, params);
}
public product findbypid(string pid) throws sqlexception {
queryrunner queryrunner = new queryrunner(c3p0utils.getdatasource());
string sql =" select * from product where pid = ? ";
object [] params = {pid};
return queryrunner.query(sql, new beanhandler<product>(product.class), params);
}
public boolean update(product product) throws sqlexception {
queryrunner queryrunner = new queryrunner(c3p0utils.getdatasource());
string sql = " update product set pname = ? , shop_price = ? , pdesc = ? , cid = ? where pid = ? ";
object [] params = {
product.getpname() , product.getshop_price() , product.getpdesc() ,
product.getcid() , product.getpid()
};
return queryrunner.update(sql, params) > 0 ;
}
public int deletebypid(string pid) throws sqlexception {
queryrunner queryrunner = new queryrunner(c3p0utils.getdatasource());
string sql = " delete from product where pid = ? ";
object [] params = {
pid
};
return queryrunner.update(sql, params) ;
}
/**
* 处理乱码的工具类
*
*/
public class encodingfilter implements filter {
public void destroy() {
// todo auto-generated method stub
}
public void dofilter(servletrequest req, servletresponse resp, filterchain chain) throws ioexception, servletexception {
final httpservletrequest request = (httpservletrequest)req;
httpservletresponse response = (httpservletresponse)resp;
try {
//处理post乱码
request.setcharacterencoding("utf-8");
//处理响应
response.setheader("content-type", "text/html;charset=utf-8");
//处理get乱码
httpservletrequest myrequest = (httpservletrequest)proxy.newproxyinstance(
encodingfilter.class.getclassloader(),
request.getclass().getinterfaces(),
new invocationhandler() {
@override
public object invoke(object proxy, method method, object[] args) throws throwable {
//可以对getparameter进行增强 get提交方式
//1.判断是get请求方式
string requestmethod= request.getmethod();
if("get".equalsignorecase(requestmethod)){
//get提交 只对getparameter方法进行拦截
string methodname = method.getname();
if("getparameter".equals(methodname)){
//get方式 并且 调用的getparameter方法
//获得以前乱码 return 不乱码
string tempvalue = request.getparameter(args[0].tostring());
//如果没有获得数据 防止空指针
if(tempvalue == null){
return null;
}
return new string(tempvalue.getbytes("iso-8859-1"),"utf-8");
}
}
//不需要增强
return method.invoke(request, args);
}
});
//放行
chain.dofilter(myrequest, response);
} catch (exception e) {
// todo auto-generated catch block
e.printstacktrace();
}
}
public void init(filterconfig fconfig) throws servletexception {
// todo auto-generated method stub
}
}
jsp代码:
<%-- 获得数据 并遍历 --%>
<c:foreach items="${pagebean.data}" var="product">
<tr onmouseover="this.style.backgroundcolor = '#f5fafe'"
onmouseout="this.style.backgroundcolor = '#fff';">
<td style="cursor: hand; height: 22px" align="center">
<input type="checkbox" name="" value="" />
</td>
<td style="cursor: hand; height: 22px" align="center">
<img src="${pagecontext.request.contextpath}/${product.pimage}" style="height: 200px;width:150px" />
</td>
<td style="cursor: hand; height: 22px" align="center">
${product.cid}
</td>
<td style="cursor: hand; height: 22px" align="center">
${product.pname}
</td>
<td style="cursor: hand; height: 22px" align="center">
${product.shop_price}
</td>
<td style="cursor: hand; height: 22px" align="center">
${product.pdesc}
</td>
<td align="center" style="height: 22px">
<%--编辑 --%>
<a href="${pagecontext.request.contextpath}/productservlet?pid=${product.pid}&method=findbypid">
<img src="${pagecontext.request.contextpath}/images/i_edit.gif" border="0" style="cursor: hand">
</a>
</td>
<td align="center" style="height: 22px">
<%--查询 --%>
<a href="../user/view.html?userid=15">
<img src="${pagecontext.request.contextpath}/images/button_view.gif" border="0" style="cursor: hand">
</a>
</td>
<td align="center" style="height: 22px">
<%--删除 ctrl + q --%>
<a href="${pagecontext.request.contextpath}/productservlet?method=deletebypid&pid=${product.pid}">
<img src="${pagecontext.request.contextpath}/images/i_del.gif" width="16" height="16" border="0" style="cursor: hand">
</a>
<%--提示删除 --%>
<a href="javascript:void(0)" onclick="deletebypid('${product.pid}')">
<img src="${pagecontext.request.contextpath}/images/i_del.gif" width="16" height="16" border="0" style="cursor: hand">
</a>
</td>
</tr>
</c:foreach>
<%-- 获得数据 并遍历 --%>
<script>
//javascript 需要在写在 header标签中
function deletebypid(pid){
//alert(pid);
//提示用户
var flag = confirm("您确定要删除信息吗?");
if(flag){
//确定删除
//访问服务器删除的servlet
//修改地址栏 跳转路径 等效我们自己点击超链接
location.href="${pagecontext.request.contextpath}/productservlet?method=deletebypid&pid="+pid;
}
}
</script>
</table>
</td>
</tr>
</tbody>
</table>
<!--分页 class="disabled" class="active"-->
<div style="width:1100px;margin:0 auto;margin-top:50px;">
<ul class="pagination" style="text-align:center; margin-top:10px;">
<%-- 如果当前页 等于 1 不需要再显示上一页 如果当前不等于1 显示 --%>
<c:if test="${pagebean.pagenumber != 1}">
<li ><a href="${pagecontext.request.contextpath}/productservlet?method=findall&pagenumber=1" aria-label="previous"><span aria-hidden="true">«</span></a></li>
<li ><a href="${pagecontext.request.contextpath}/productservlet?method=findall&pagenumber=${pagebean.pagenumber - 1 }" aria-label="previous"><span aria-hidden="true">上一页</span></a></li>
</c:if>
<%-- 循环显示 所有的页数 --%>
<c:foreach begin="${pagebean.start}" end="${pagebean.end}" var="num" step="1">
<li ${pagebean.pagenumber == num ? " class='active'" : ""} ><a href="${pagecontext.request.contextpath}/productservlet?method=findall&pagenumber=${num}">${num}</a></li>
</c:foreach>
<%-- 如果当前页小于总页数 显示下一页 --%>
<c:if test="${pagebean.pagenumber < pagebean.totalpage}">
<li><a href="${pagecontext.request.contextpath}/productservlet?method=findall&pagenumber=${pagebean.pagenumber + 1 }" aria-label="next"><span aria-hidden="true">下一页</span></a></li>
<li><a href="${pagecontext.request.contextpath}/productservlet?method=findall&pagenumber=${pagebean.totalpage}" aria-label="next"><span aria-hidden="true">»</span></a></li>
</c:if>
</ul>
</div>
<!-- 分页结束======================= -->
条件查询：
1: 先在首页上查询分类数据,并且遍历显示
分析:
select * from product where cid = ? and pname = ?;
含有的可能性:
1.两者都有.
2.两者都没有.
3.有cid但没有pname
4.没有cid但有pname
select count(*) from product where 1=1;
伪代码:
sql = " select * from product where 1=1 ";
if(cid != null) {
sql += " and cid = ? "
}
if(pname != null) {
sql += " and pname like ? "
}
1: 修改表单 action属性,method属性,name属性,自定义的method判断逻辑.
2: 调用servlet
a : 获得 cid和pname
b : 处理 调用service 调用dao(重要)
c : 响应 - 将数据存到request里,请求转发给product_list.jsp
3.对jsp页面进行改造
条件查询注意事项:
1 . dao的sql部分,拼接的问题,使用 where 1=1 解决了脏读、不可重复读、
2 . dao的参数拼接部分,使用list接收数据,最后将list转换成数组,解决.
3 . 查询完以后将数据返回给页面,但还需要加上,用户传入后台的cid和pname;
切记:条件查询 不可以 和 分页 同一个项目 但以后 条件查询需要和分页结合
4 . 如果条件查询和分页需要做到同一个项目,需要处理参数问题.
5 . pagebean 查询总记录数 --> 如果加入条件查询,查询总记录数时需要加上条件.
案例:代码体现
public class productservlet extends httpservlet {
protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {
try {
//获得页面传递的参数 用来执行某段代码
string method = request.getparameter("method");
productservice pservice = new productservice();
categoryservice cservice = new categoryservice();
//根据页面功能执行某段特殊的代码
if("findall".equals(method)){
//执行查询所有的代码
//1.获得
//1.31 获得cid
string cid = request.getparameter("cid");
//1.2 获得pname
string pname = request.getparameter("pname");
//2.处理
list<product> plist = pservice.findall( cid , pname );
list<category> clist = cservice.findall();
//3.响应
//3.1 将数据存到request
request.setattribute("plist", plist);
request.setattribute("clist", clist);
request.setattribute("cid", cid);
request.setattribute("pname", pname);
//3.2 请求转发给jsp
request.getrequestdispatcher("/admin/product/product_list.jsp").forward(request, response);
return;
}
public class productdao {
/**
* 条件查询
* @param cid
* @param pname
* @return
* @throws sqlexception
*/
public list<product> findall(string cid, string pname) throws sqlexception {
queryrunner queryrunner = new queryrunner(c3p0utils.getdatasource());
string sql = " select * from product where 1=1 ";
//定义一个list 作用 用来保存参数
list<object> paramlist = new arraylist<object>();
//cid判断
if(cid != null && !"".equals(cid)){
sql += " and cid = ? ";
paramlist.add(cid);
}
//pname判断
if(pname != null && !"".equals(pname)){
sql += " and pname like ? ";
paramlist.add("%"+pname+"%");
}
//数组的缺陷 长度固定 集合的长度不固定 集合最后转换成数组
object [] params = paramlist.toarray();
return queryrunner.query(sql,new beanlisthandler<product>(product.class), params);
}
<form action="${pagecontext.request.contextpath}/productservlet" method="post">
<%--隐藏域 --%>
<input type="hidden" name="method" value="findall"/>
<table cellpadding="0" cellspacing="0" border="0" width="100%">
<tr>
<td height="22" align="center" bgcolor="#f5fafe" class="ta_01" style="width: 15%">
分类
</td>
<td class="ta_01" bgcolor="#ffffff" style="width: 30%">
<select name="cid" class="form-control">
<option value="">请选择</option>
<c:foreach items="${clist}" var="category">
<option ${category.cid==cid ? "selected" : ""} value="${category.cid}">${category.cname}</option>
</c:foreach>
</select>
</td>
<td height="22" align="center" bgcolor="#f5fafe" class="ta_01" style="width: 15%">
商品名称：
</td>
<td class="ta_01" bgcolor="#ffffff">
<input type="text" name="pname" size="15" value="${pname}" class="form-control"/>
</td>
批量删除:
思想:
前台两套方法:
1 . 表单提交:将所有被选中的数据,的pid传入后台,后台执行批量删除.
2 . 修改sql 修改成 sql=" delete from product where pid in (?) " 数据循环拼接 1,2,4
3 . 开发中会使用jdbc jdbc当中有批处理,也可以处理批量任务.
事务特性:
a : 原子性;
c : 一致性;
i : 隔离性 : isolation 隔离会产生隔离问题
d : 持久性.
protected void doget(httpservletrequest request, httpservletresponse response) throws servletexception, ioexception {
try {
//获得页面传递的参数 用来执行某段代码
string method = request.getparameter("method");
productservice pservice = new productservice();
categoryservice cservice = new categoryservice();
//根据pid删除商品
if("deletebypid".equals(method)){
//1.获得
//获得数组集合
string[] pids = request.getparametervalues("pid");
//2.处理
int count = pservice.deletebypid(pids);
//3.响应
if(count > 0){
response.sendredirect(request.getcontextpath() + "/productservlet?method=findall");
}
return;
}
<td align="center" width="6%">
<input type="button" value="删除选中" onclick="deleteall()">
<script>
function deleteall(){
//1.提示
var flag = confirm("您确定要删除信息吗?");
if(!flag){
return ;
}
//2.获得所有选中的pid 获得所有的数组 最后的格式 pid=1&pid=2&pid3..
var pids = $("input[name='pid']:checked").serialize() ;
//3.发送
location.href="${pagecontext.request.contextpath}/productservlet?method=deletebypid&"+pids;
}
</script>
</td>
<td align="center" width="15%">
预览图
</td>
<td align="center" width="12%">
商品分类
</td>
<td align="center" width="25%">
商品名称
</td>
<td align="center" width="8%">
商品价格
</td>
<td width="11%" align="center">
描述
</td>
<td width="7%" align="center">
编辑
</td>
<td width="7%" align="center">
查看
</td>
<td width="7%" align="center">
删除
</td>
</tr>
<%-- 获得数据 并遍历 --%>
<c:foreach items="${plist}" var="product">
<tr onmouseover="this.style.backgroundcolor = '#f5fafe'"
onmouseout="this.style.backgroundcolor = '#fff';">
<td style="cursor: hand; height: 22px" align="center">
<input type="checkbox" name="pid" value="${product.pid}" />
</td>
<td style="cursor: hand; height: 22px" align="center">
<img src="${pagecontext.request.contextpath}/${product.pimage}" style="height: 200px;width:150px" />
</td>
<td style="cursor: hand; height: 22px" align="center">
${product.cid}
</td>
<td style="cursor: hand; height: 22px" align="center">
${product.pname}
</td>
<td style="cursor: hand; height: 22px" align="center">
${product.shop_price}
</td>
<td style="cursor: hand; height: 22px" align="center">
${product.pdesc}
</td>
<td align="center" style="height: 22px">
<%--编辑 --%>
<a href="${pagecontext.request.contextpath}/productservlet?pid=${product.pid}&method=findbypid">
<img src="${pagecontext.request.contextpath}/images/i_edit.gif" border="0" style="cursor: hand">
</a>
</td>
<td align="center" style="height: 22px">
<%--查询 --%>
<a href="../user/view.html?userid=15">
<img src="${pagecontext.request.contextpath}/images/button_view.gif" border="0" style="cursor: hand">
</a>
</td>
<td align="center" style="height: 22px">
<%--删除 ctrl + q --%>
<a href="${pagecontext.request.contextpath}/productservlet?method=deletebypid&pid=${product.pid}">
<img src="${pagecontext.request.contextpath}/images/i_del.gif" width="16" height="16" border="0" style="cursor: hand">
</a>
<%--提示删除 --%>
<a href="javascript:void(0)" onclick="deletebypid('${product.pid}')">
<img src="${pagecontext.request.contextpath}/images/i_del.gif" width="16" height="16" border="0" style="cursor: hand">
</a>
</td>
</tr>
</c:foreach>
<%-- 获得数据 并遍历 --%>
<script>
//javascript 需要在写在 header标签中
function deletebypid(pid){
//alert(pid);
//提示用户
var flag = confirm("您确定要删除信息吗?");
if(flag){
//确定删除
//访问服务器删除的servlet
//修改地址栏 跳转路径 等效我们自己点击超链接
location.href="${pagecontext.request.contextpath}/productservlet?method=deletebypid&pid="+pid;
}
}
</script>
</table>
</td>
</tr>
</tbodjy>
</table>
数据库开启手动提交以后,只要commit以后,会改成自动提交.查一下是否改成了自动提交
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