Archetype Created Web ApplicationcontextConfigLocationclasspath:spring-context.xmlorg.springframework.web.context.ContextLoaderListenerencodingFilterorg.springframework.web.filter.CharacterEncodingFiltertrueencodingUTF-8encodingFilter/*SpringMVCorg.springframework.web.servlet.DispatcherServletcontextConfigLocationclasspath:spring-mvc.xml1trueSpringMVC/
二、逆向生成增删改查
2.1.导入相关util类
①StringUtils.java
package com.csdn.xw.util;
public class StringUtils {
// 私有的构造方法，保护此类不能在外部实例化
private StringUtils() {
}
/**
* 如果字符串等于null或去空格后等于""，则返回true，否则返回false
*
* @param s
* @return
*/
public static boolean isBlank(String s) {
boolean b = false;
if (null == s || s.trim().equals("")) {
b = true;
}
return b;
}
/**
* 如果字符串不等于null或去空格后不等于""，则返回true，否则返回false
*
* @param s
* @return
*/
public static boolean isNotBlank(String s) {
return !isBlank(s);
}
}
②PageBean.java
package com.csdn.xw.util;
import javax.servlet.http.HttpServletRequest;
import java.util.HashMap;
import java.util.Map;
/**
* @author Java方文山
* @compay csdn_Java方文山
* @create 2023-09-07-16:28
*/
public class PageBean {
private int page = 1;// 页码
private int rows = 10;// 页大小
private int total = 0;// 总记录数
private boolean pagination = true;// 是否分页
private String url; //保存上一次请求的URL
private Map paramMap = new HashMap<>();// 保存上一次请求的参数
/**
* 初始化pagebean的，保存上一次请求的重要参数
* @param req
*/
public void setRequest(HttpServletRequest req) {
// 1.1 需要保存上一次请求的URL
this.setUrl(req.getRequestURL().toString());
// 1.2 需要保存上一次请求的参数 bname、price
this.setParamMap(req.getParameterMap());
// 1.3 需要保存上一次请求的分页设置 pagination
this.setPagination(req.getParameter("pagination"));
// 1.4 需要保存上一次请求的展示条目数
this.setRows(req.getParameter("rows"));
// 1.5 初始化请求的页码 page
this.setPage(req.getParameter("page"));
}
public void setPage(String page) {
if(StringUtils.isNotBlank(page))
this.setPage(Integer.valueOf(page));
}
public void setRows(String rows) {
if(StringUtils.isNotBlank(rows))
this.setRows(Integer.valueOf(rows));
}
public void setPagination(String pagination) {
// 只有在前台jsp填写了pagination=false，才代表不分页
if(StringUtils.isNotBlank(pagination))
this.setPagination(!"false".equals(pagination));
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public Map getParamMap() {
return paramMap;
}
public void setParamMap(Map paramMap) {
this.paramMap = paramMap;
}
public PageBean() {
super();
}
public int getPage() {
return page;
}
public void setPage(int page) {
this.page = page;
}
public int getRows() {
return rows;
}
public void setRows(int rows) {
this.rows = rows;
}
public int getTotal() {
return total;
}
public void setTotal(int total) {
this.total = total;
}
public void setTotal(String total) {
this.total = Integer.parseInt(total);
}
public boolean isPagination() {
return pagination;
}
public void setPagination(boolean pagination) {
this.pagination = pagination;
}
/**
* 获得起始记录的下标
*
* @return
*/
public int getStartIndex() {
return (this.page - 1) * this.rows;
}
/**
* 最大页
* @return
*/
public int maxPage() {
// total % rows == 0 ? total / rows : total / rows +1
return this.total % this.rows == 0 ? this.total / this.rows : this.total / this.rows + 1;
}
/**
* 下一页
* @return
*/
public int nextPage() {
// 如果当前页小于最大页，那就下一页为当前页+1；如果不小于，说明当前页就是最大页，那就无需+1
return this.page < this.maxPage() ? this.page + 1 : this.page;
}
/**
* 上一页
* @return
*/
public int previousPage() {
return this.page > 1 ? this.page - 1 : this.page;
}
@Override
public String toString() {
return "PageBean [page=" + page + ", rows=" + rows + ", total=" + total + ", pagination=" + pagination + "]";
}
}
public interface StudentBiz {
int deleteByPrimaryKey(String sid);
int insert(Student record);
int insertSelective(Student record);
Student selectByPrimaryKey(String sid);
int updateByPrimaryKeySelective(Student record);
int updateByPrimaryKey(Student record);
List selectBySnamePager(Student student,PageBean PageBean);
}
StudentBizImpl
package com.csdn.xw.Biz.Impl;
import com.csdn.xw.Biz.StudentBiz;
import com.csdn.xw.mapper.StudentMapper;
import com.csdn.xw.model.Student;
import com.csdn.xw.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
/**
* @author Java方文山
* @compay csdn_Java方文山
* @create 2023-09-07-16:22
*/
@Service
public class StudentBizImpl implements StudentBiz {
@Autowired
private StudentMapper studentMapper;
@Override
public int deleteByPrimaryKey(String sid) {
return studentMapper.deleteByPrimaryKey(sid);
}
@Override
public int insert(Student record) {
return studentMapper.insert(record);
}
@Override
public int insertSelective(Student record) {
return studentMapper.insertSelective(record);
}
@Override
public Student selectByPrimaryKey(String sid) {
return studentMapper.selectByPrimaryKey(sid);
}
@Override
public int updateByPrimaryKeySelective(Student record) {
return studentMapper.updateByPrimaryKeySelective(record);
}
@Override
public int updateByPrimaryKey(Student record) {
return studentMapper.updateByPrimaryKey(record);
}
@Override
public List selectBySnamePager(Student student, PageBean PageBean) {
return studentMapper.selectBySnamePager(student);
}
}
至此，我们的增删改查加模糊查询的分页所有方法就写完了。
三、controller层代码编写
首先建一个名为web的包，随后建立一个StudentController。
StudentController
@Controller
@RequestMapping("/student")
public class StudentController {
@Autowired
private StudentBiz stubiz;
// 增
@RequestMapping("/add")
public String add(Student student){
stubiz.insertSelective(student);
return "redirect:list";
}
// 删
@RequestMapping("/del")
public String del(Student student){
stubiz.deleteByPrimaryKey(student.getSid());
return "redirect:list";
}
// 查
@RequestMapping("/list")
public String list(Student student, HttpServletRequest request){
PageBean pageBean=new PageBean();
pageBean.setRequest(request);
List students = stubiz.selectBySnamePager(student, pageBean);
request.setAttribute("slist",students);
request.setAttribute("pageBean",pageBean);
return "student/list";
}
// 改
@RequestMapping("/edit")
public String edit(Student student){
stubiz.updateByPrimaryKeySelective(student);
return "redirect:list";
}
// 模糊分页查询
@RequestMapping("/PreSave")
public String PreSave(Student student, HttpServletRequest request){
if(student!=null && student.getSid()!=null){
Student s = stubiz.selectByPrimaryKey(student.getSid());
request.setAttribute("s",s);
}
return "student/edit";
}
}
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml&q
// for循环的进化
// 菜鸟
for (var i = 0; i < Things.length ; i++) {
// Things[i]
}
// 老鸟
for (var i = 0, len = Things.length; i < len; i++) {
// Things[i]
}
// 大师
for (var i = Things.le
the idea is from:
http://blog.csdn.net/zhanxinhang/article/details/6731134
public class MaxSubMatrix {
/**see http://blog.csdn.net/zhanxinhang/article/details/6731134
* Q35
求一个矩阵中最大的二维
使用cordova可以很方便的在手机sdcard中读写文件。
首先需要安装cordova插件：file
命令为：
cordova plugin add org.apache.cordova.file
然后就可以读写文件了，这里我先是写入一个文件，具体的JS代码为：
var datas=null;//datas need write
var directory=&
SELECT cust_id,
SUM(price) as total
FROM orders
WHERE status = 'A'
GROUP BY cust_id
HAVING total > 250
db.orders.aggregate( [
{ $match: { status: 'A' } },
{
$group: {
