自定义MVC框架（实现增删改查）
目录
一.环境配置
1.1、导入jar包
2.2.将分页标签相关文件、及相关助手类导入
三.通用增删改查
四.后台代码
五.前端代码
这篇 自定义MVC框架（实现增删改查）就介绍到这里了，欢迎大佬来提建议哦！！！！
一.环境配置
1.1、导入jar包
首先将我们前面写的代码打成一个jar包然后导入我们的项目：
其次把它导成jar包：
就是这样一个图形你就成功了
最后把它导入项目中
好啦第一步就成功了。接下来我们就
2.2.将分页标签相关文件、及相关助手类导入
将之前util包导入进来
BaseDao
package com.junlinyi.util;
import java.lang.reflect.Field;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import com.junlinyi.util.DBAccess;
import com.junlinyi.util.PageBean;
import com.junlinyi.util.StringUtils;
/**
* 所有Dao层的父类
* BookDao
* UserDao
* OrderDao
* ...
* @author Administrator
*
* @param
*/
public class BaseDao {
/**
* 通用的增删改方法
* @param sql 增删改sql
* @param t sql中的表对应的实体类
* @param attrs 实体类对应的属性
* @return
* @throws Exception
*/
public int executeUpdate(String sql,T t,String[] attrs) throws Exception {
Connection con = DBAccess.getConnection();
PreparedStatement ps = con.prepareStatement(sql);
for (int i = 0; i < attrs.length; i++) {
Field f = t.getClass().getDeclaredField(attrs[i]);
f.setAccessible(true);
ps.setObject(i+1,f.get(t));
}
return ps.executeUpdate();
}
/**
* 通用分页查询
* @param sql
* @param clz
* @return
* @throws Exception
*/
public List executeQuery(String sql,Class clz,PageBean pageBean) throws Exception{
List list = new ArrayList();
Connection con = DBAccess.getConnection();;
PreparedStatement pst = null;
ResultSet rs = null;
/*
* 是否需要分页？
* 无需分页（项目中的下拉框，查询条件教员下拉框，无须分页）
* 必须分页（项目中列表类需求、订单列表、商品列表、学生列表...）
*/
if(pageBean != null && pageBean.isPagination()) {
// 必须分页（列表需求）
String countSQL = getCountSQL(sql);
pst = con.prepareStatement(countSQL);
rs = pst.executeQuery();
if(rs.next()) {
pageBean.setTotal(String.valueOf(rs.getObject(1)));
}
// 挪动到下面，是因为最后才处理返回的结果集
// -- sql=SELECT * FROM t_mvc_book WHERE bname like '%圣墟%'
// -- pageSql=sql limit (page-1)*rows,rows 对应某一页的数据
// -- countSql=select count(1) from (sql) t 符合条件的总记录数
String pageSQL = getPageSQL(sql,pageBean);//符合条件的某一页数据
pst = con.prepareStatement(pageSQL);
rs = pst.executeQuery();
}else {
// 不分页（select需求）
pst = con.prepareStatement(sql);//符合条件的所有数据
rs = pst.executeQuery();
}
while (rs.next()) {
T t = clz.newInstance();
Field[] fields = clz.getDeclaredFields();
for (Field f : fields) {
f.setAccessible(true);
f.set(t, rs.getObject(f.getName()));
}
list.add(t);
}
return list;
}
/**
* 将原生SQL转换成符合条件的总记录数countSQL
* @param sql
* @return
*/
private String getCountSQL(String sql) {
// -- countSql=select count(1) from (sql) t 符合条件的总记录数
return "select count(1) from ("+sql+") t";
}
/**
* 将原生SQL转换成pageSQL
* @param sql
* @param pageBean
* @return
*/
private String getPageSQL(String sql,PageBean pageBean) {
// (this.page - 1) * this.rows
// pageSql=sql limit (page-1)*rows,rows
return sql + " limit "+ pageBean.getStartIndex() +","+pageBean.getRows();
}
}
DBAccess
package com.junlinyi.util;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
/**
* 提供了一组获得或关闭数据库对象的方法
*
*/
public class DBAccess {
private static String driver;
private static String url;
private static String user;
private static String password;
static {// 静态块执行一次，加载 驱动一次
try {
InputStream is = DBAccess.class
.getResourceAsStream("config.properties");
Properties properties = new Properties();
properties.load(is);
driver = properties.getProperty("driver");
url = properties.getProperty("url");
user = properties.getProperty("user");
password = properties.getProperty("pwd");
Class.forName(driver);
} catch (Exception e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
/**
* 获得数据连接对象
*
* @return
*/
public static Connection getConnection() {
try {
Connection conn = DriverManager.getConnection(url, user, password);
return conn;
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
public static void close(ResultSet rs) {
if (null != rs) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
}
public static void close(Statement stmt) {
if (null != stmt) {
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
}
public static void close(Connection conn) {
if (null != conn) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
throw new RuntimeException(e);
}
}
}
public static void close(Connection conn, Statement stmt, ResultSet rs) {
close(rs);
close(stmt);
close(conn);
}
public static boolean isOracle() {
return "oracle.jdbc.driver.OracleDriver".equals(driver);
}
public static boolean isSQLServer() {
return "com.microsoft.sqlserver.jdbc.SQLServerDriver".equals(driver);
}
public static boolean isMysql() {
return "com.mysql.cj.jdbc.Driver".equals(driver);
}
public static void main(String[] args) {
Connection conn = DBAccess.getConnection();
System.out.println(conn);
DBAccess.close(conn);
System.out.println("isOracle：" + isOracle());
System.out.println("isSQLServer：" + isSQLServer());
System.out.println("isMysql：" + isMysql());
System.out.println("数据库连接(关闭)成功");
}
}
EncodingFiter
package com.junlinyi.util;
import java.io.IOException;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* 中文乱码处理
*
*/
@WebFilter("*.action")
public class EncodingFiter implements Filter {
private String encoding = "UTF-8";// 默认字符集
public EncodingFiter() {
super();
}
public void destroy() {
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) request;
HttpServletResponse res = (HttpServletResponse) response;
// 中文处理必须放到 chain.doFilter(request, response)方法前面
res.setContentType("text/html;charset=" + this.encoding);
if (req.getMethod().equalsIgnoreCase("post")) {
req.setCharacterEncoding(this.encoding);
} else {
Map map = req.getParameterMap();// 保存所有参数名=参数值(数组)的Map集合
Set set = map.keySet();// 取出所有参数名
Iterator it = set.iterator();
while (it.hasNext()) {
String name = (String) it.next();
String[] values = (String[]) map.get(name);// 取出参数值[注：参数值为一个数组]
for (int i = 0; i < values.length; i++) {
values[i] = new String(values[i].getBytes("ISO-8859-1"),
this.encoding);
}
}
}
chain.doFilter(request, response);
}
public void init(FilterConfig filterConfig) throws ServletException {
String s = filterConfig.getInitParameter("encoding");// 读取web.xml文件中配置的字符集
if (null != s && !s.trim().equals("")) {
this.encoding = s.trim();
}
}
}
PageBean :分页工具类
package com.junlinyi.util;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
/**
* 分页工具类
*
*/
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 + "]";
}
}
StringUtils
package com.junlinyi.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);
}
}
数据库连接
#oracle9i
#driver=oracle.jdbc.driver.OracleDriver
#url=jdbc:oracle:thin:@localhost:1521:ora9
#user=test
#pwd=test
#sql2005
#driver=com.microsoft.sqlserver.jdbc.SQLServerDriver
#url=jdbc:sqlserver://localhost:1423;DatabaseName=test
#user=sa
#pwd=sa
#sql2000
#driver=com.microsoft.jdbc.sqlserver.SQLServerDriver
#url=jdbc:microsoft:sqlserver://localhost:1433;databaseName=unit6DB
#user=sa
#pwd=888888
#mysql5
#driver=com.mysql.jdbc.Driver
#url=jdbc:mysql://127.0.0.1:3306/mybatis_ssm?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT
#user=mybatis_ssm
#pwd=xiaoli
#mysql8
driver=com.mysql.cj.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/mybatis_ssm?useUnicode=true&characterEncoding=utf8&serverTimezone=GMT&useSSL=true
user=root
pwd=123456
PageTag
package com.junlinyi.tag;
import java.io.IOException;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.BodyTagSupport;
import com.junlinyi.util.PageBean;
public class PageTag extends BodyTagSupport{
private PageBean pageBean;// 包含了所有分页相关的元素
public PageBean getPageBean() {
return pageBean;
}
public void setPageBean(PageBean pageBean) {
this.pageBean = pageBean;
}
@Override
public int doStartTag() throws JspException {
// 没有标签体，要输出内容
JspWriter out = pageContext.getOut();
try {
out.print(toHTML());
} catch (IOException e) {
e.printStackTrace();
}
return super.doStartTag();
}
private String toHTML() {
StringBuffer sb = new StringBuffer();
// 隐藏的form表单---这个就是上一次请求下次重新发的奥义所在
// 上一次请求的URL
sb.append("");
// 分页条
sb.append("");
// 分页执行的JS代码
sb.append("");
return sb.toString();
}
}
最后配置框架配置
JunLunYi_MVC_crud
index.html
index.htm
index.jsp
default.html
default.htm
default.jsp
mvc
com.zking.framework.DispatchServlet
configurationLocation
/mvc.xml
mvc
*.action
三.通用增删改查
发现前面写增删改查的代码很繁琐而且有待改进。可以利用自定义MVC框架来做到简化冗余代码的同时实现与之相同的功能。这是用MVC框架来实现的代码(以书籍管理系统为例)，如下：
一样的建一个书籍类：
package com.junlinyi.entity;
/**
*实体类
* @author： 君临沂
*
*/
public class Book {
private int bid;
private String bname;
private float price;
public int getBid() {
return bid;
}
public void setBid(int bid) {
this.bid = bid;
}
public String getBname() {
return bname;
}
public void setBname(String bname) {
this.bname = bname;
}
public float getPrice() {
return price;
}
public void setPrice(float price) {
this.price = price;
}
public Book() {
// TODO Auto-generated constructor stub
}
public Book(int bid, String bname, float price) {
super();
this.bid = bid;
this.bname = bname;
this.price = price;
}
@Override
public String toString() {
return "Book [bid=" + bid + ", bname=" + bname + ", price=" + price + "]";
}
}
再建dao类 ：写增删改查方法
package com.junlinyi.dao;
import java.util.List;
import com.junlinyi.entity.Book;
import com.junlinyi.util.BaseDao;
import com.junlinyi.util.PageBean;
import com.junlinyi.util.StringUtils;
/**
*
* @author： 君临沂
*
*/
public class BookDao extends BaseDao {
// 查询
public List list(Book book, PageBean pageBean) throws Exception {
String sql="select * from t_mvc_book where 1=1";
String bname = book.getBname();
int bid = book.getBid();
if(StringUtils.isNotBlank(bname)) {
sql +=" and bname like '%"+bname+"%'";
}
// bod==0 意味着前台没有传递bid值
if(bid !=0) {
sql +="and bid ="+ bid;
}
return super.executeQuery(sql, Book.class, pageBean);
}
// 增加
public int add(Book book) throws Exception {
String sql="insert into t_mvc_book values(?,?,?)";
return super.executeUpdate(sql,book,new String[] {"bid","bname","price"});
}
// 删除
public int del(Book book) throws Exception {
String sql="delete from t_mvc_book where bid=?";
return super.executeUpdate(sql,book,new String[] {"bid"});
}
// 修改
public int upd(Book book) throws Exception {
String sql="update t_mvc_book set bname=?,price=? where bid=?";
return super.executeUpdate(sql,book,new String[] {"bname","price","bid"});
}
}
测试：
package com.junlinyi.dao;
import static org.junit.Assert.*;
import java.util.List;
import org.junit.Test;
import com.junlinyi.entity.Book;
import com.junlinyi.util.PageBean;
public class BookDaoTest {
private BookDao bookDao=new BookDao();
@Test
public void testList() throws Exception {
Book book=new Book();
book.setBname("圣墟");
PageBean pageBean=new PageBean();
pageBean.setPage(3);
List list = bookDao.list(book,pageBean);
for (Book b : list) {
System.out.println(b);
}
}
@Test
public void testAdd() throws Exception {
Book book=new Book(52,"圣墟",99);
bookDao.add(book);
}
@Test
public void testDel() throws Exception {
Book book=new Book();
book.setBid(52);
bookDao.del(book);
}
@Test
public void testUpd() throws Exception {
Book book=new Book(52,"圣墟第52章",90);
bookDao.upd(book);
}
}
方法代码写完我们来测试一下增删改查
通过测试增删改方法没有问题，接下来我们下一步操作。
四.后台代码
接下来我们用我们简单的布局在浏览器中实现增删改查
BookAction
package com.junlinyi.web;
import java.util.List;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.junlinyi.dao.BookDao;
import com.junlinyi.entity.Book;
import com.junlinyi.util.PageBean;
import com.zking.framework.ActionSupport;
import com.zking.framework.ModelDriver;
public class BookAction extends ActionSupport implements ModelDriver {
private Book book = new Book();
private BookDao bookDao = new BookDao();
// 查询 booklist.jsp
public String list(HttpServletRequest req, HttpServletResponse resp) throws Exception {
PageBean pageBean = new PageBean();
// 初始化
pageBean.setRequest(req);
List list = bookDao.list(book, pageBean);
req.setAttribute("list", list);
req.setAttribute("PageBean", pageBean);
return "list";
}
// 编辑页面跳转 bookUpd.jsp
public String toUpd(HttpServletRequest req, HttpServletResponse resp) throws Exception {
if (book.getBid() != 0) {
List list = bookDao.list(book, null);
req.setAttribute("b", list.get(0));
}
return "toUpd";
}
// 增加
public String add(HttpServletRequest req, HttpServletResponse resp) throws Exception {
bookDao.add(book);
return "addList";
}
// 删除
public String del(HttpServletRequest req, HttpServletResponse resp) throws Exception {
bookDao.del(book);
return "delList";
}
// 修改
public String upd(HttpServletRequest req, HttpServletResponse resp) throws Exception {
bookDao.upd(book);
return "updList";
}
@Override
public Book getModel() {
return book;
}
}
将BookAction配置到mvc.xmml中
五.前端代码
cv我们之前写的BookList.Jsp:
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://www/JunLinYi/com" prefix="z"%>
书籍列表
${pageBean }
书籍ID
书籍名
价格
操作
${b.bid }
${b.bname }
${b.price }
修改
删除
bookUpd.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
书籍编辑页面（修改/增加共用）
名称：
价格：
实现图：
这篇 自定义MVC框架（实现增删改查）就介绍到这里了，欢迎大佬来提建议哦！！！！