• 自定义MVC增删改查

    目录

    一、搭建自定义MVC框架环境

    1.将框架导成jar包，然后导入新工程，并且将框架的依赖jar包导入

     2.将分页标签相关文件、以及相关助手类导入，框架的配置文件添加以及web.xml的配置

    二、基础的增删改

     三、通用的增删改

     四、查询删除及重复表单提交问题

    五、新增修改的前端实现

    一、搭建自定义MVC框架环境

    1.将框架导成jar包，然后导入新工程，并且将框架的依赖jar包导入

    如图：导出自己的jar包

     

     

     取个名字

     找到该jar包，放入新建项目的lib下，该包为核心包

    再导入其他依赖包

     

     2.将分页标签相关文件、以及相关助手类导入，框架的配置文件添加以及web.xml的配置

     配置中央控制器的.xml的坏境

    web.xml的源码

    1. <?xml version="1.0" encoding="UTF-8"?>
    2. <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
    3.   <display-name>T280_mvc_crud</display-name>
    4.   <servlet>
    5.   	<servlet-name>mvc</servlet-name>
    6.   	<servlet-class>com.cdl.framework.DispatcherServlet</servlet-class>
    7.  	<init-param>
    8.  		<param-name>configLaction</param-name>
    9.  		<param-value>/wuyanzu</param-value>
    10.  	</init-param>
    11.   </servlet>
    12.   <servlet-mapping>
    13.   	<servlet-name>mvc</servlet-name>
    14.   	<url-pattern>*.action</url-pattern>
    15.   </servlet-mapping>
    16. </web-app>

    将助手类一级tld的配置文件拿过来,如图结构

     注意：目前所有的包的内容均再通用分页的博客中有

    以后的开元框架都从这一步开始

    二、基础的增删改

    建一个com.cdl.entity的包，里面放实体类

    Book

    1. package com.cdl.entity;
    2.  
    3. public class Book {
    4. 	private int bid;
    5. 	private String bname;
    6. 	private float price;
    7.  
    8. 	@Override
    9. 	public String toString() {
    10. 		return "Book [bid=" + bid + ", bname=" + bname + ", price=" + price + "]";
    11. 	}
    12.  
    13. 	public int getBid() {
    14. 		return bid;
    15. 	}
    16.  
    17. 	public void setBid(int bid) {
    18. 		this.bid = bid;
    19. 	}
    20.  
    21. 	public String getBname() {
    22. 		return bname;
    23. 	}
    24.  
    25. 	public void setBname(String bname) {
    26. 		this.bname = bname;
    27. 	}
    28.  
    29. 	public float getPrice() {
    30. 		return price;
    31. 	}
    32.  
    33. 	public void setPrice(float price) {
    34. 		this.price = price;
    35. 	}
    36. 	
    37. 	public Book() {
    38. 		// TODO Auto-generated constructor stub
    39. 	}
    40.  
    41. 	public Book(int bid, String bname, float price) {
    42. 		this.bid = bid;
    43. 		this.bname = bname;
    44. 		this.price = price;
    45. 	}
    46.  
    47. 	
    48. 	
    49. }

    在com.cdl.dao中写一个bookdao

    1. package com.cdl.dao;
    2.  
    3. import java.sql.Connection;
    4. import java.sql.ResultSet;
    5. import java.sql.SQLException;
    6. import java.util.ArrayList;
    7. import java.util.List;
    8.  
    9. import com.cdl.entity.Book;
    10. import com.cdl.util.BaseDao;
    11. import com.cdl.util.CallBack;
    12. import com.cdl.util.DBAccess;
    13. import com.cdl.util.PageBean;
    14. import com.cdl.util.StringUtils;
    15. import com.mysql.jdbc.PreparedStatement;
    16.  
    17. public class BookDao extends BaseDao<Book>{
    18. 	
    19. 	//查询
    20. 	public List<Book> list(Book book,PageBean pageBean) throws Exception{
    21. 		String sql  = "select * from t_mvc_book where 1=1 ";
    22. 		String bname = book.getBname();
    23. 		if(StringUtils.isNotBlank(bname)) {
    24. 			sql += " and bname like '%"+bname+"%' ";
    25. 		}
    26. 		int bid = book.getBid();
    27. //		前台jsp传递到后台，只要传了就有值，没传就是默认值，默认值就是0
    28. 		if(bid != 0) {
    29. 			sql += " and bid = "+bid;
    30. 		}
    31. 		return super.executeQuery(sql, pageBean, rs -> {
    32. 			List<Book> list = new ArrayList<Book>();
    33. 			try {
    34. 				while(rs.next()) {
    35. 					list.add(new Book(rs.getInt("bid"), rs.getString("bname"), rs.getFloat("price")));
    36. 				}
    37. 			} catch (SQLException e) {
    38. 				// TODO Auto-generated catch block
    39. 				e.printStackTrace();
    40. 			}
    41. 			return list;
    42. 		});
    43. 	}
    44. 	
    45. //	增
    46. 	public int add(Book book) throws Exception {
    47. 		Connection con = DBAccess.getConnection();
    48. 		String sql = "insert into t_mvc_book values(?,?,?)";
    49. 		java.sql.PreparedStatement pst = con.prepareStatement(sql);
    50. 		pst.setObject(1, book.getBid());
    51. 		pst.setObject(2, book.getBname());
    52. 		pst.setObject(3, book.getPrice());
    53. 		return pst.executeUpdate();
    54. 	}
    55. 	
    56. //	删
    57. 	public int del(Book book) throws Exception {
    58. 		Connection con = DBAccess.getConnection();
    59. 		String sql = "delete from t_mvc_book where bid=?";
    60. 		java.sql.PreparedStatement pst = con.prepareStatement(sql);
    61. 		pst.setObject(1, book.getBid());
    62. 		return pst.executeUpdate();
    63. 	}
    64. 	
    65. //	改
    66. 	public int edit(Book book) throws Exception {
    67. 		Connection con = DBAccess.getConnection();
    68. 		String sql = "update t_mvc_book set bname=?,price=?  where bid=?";
    69. 		java.sql.PreparedStatement pst = con.prepareStatement(sql);
    70. 		pst.setObject(3, book.getBid());
    71. 		pst.setObject(1, book.getBname());
    72. 		pst.setObject(2, book.getPrice());
    73. 		return pst.executeUpdate();
    74. 	}
    75. 	
    76. 	
    77. 	
    78. }

    在当前类，快捷键ctrl+n,输入junit，建立一个测试类

    1. package com.cdl.dao;
    2.  
    3. import static org.junit.Assert.*;
    4.  
    5. import java.util.List;
    6.  
    7. import org.junit.Test;
    8.  
    9. import com.cdl.entity.Book;
    10. import com.cdl.util.PageBean;
    11.  
    12. public class BookDaoTest {
    13. 	
    14. 	private BookDao  bookDao = new BookDao();
    15. 	
    16. 	
    17. 	@Test
    18. 	public void testList() {
    19. 		try {
    20. 			List<Book> list = bookDao.list(new Book(), new PageBean());
    21. 			for (Book book : list) {
    22. 				System.out.println(book);
    23. 			}
    24. 		} catch (Exception e) {
    25. 			// TODO Auto-generated catch block
    26. 			e.printStackTrace();
    27. 		}
    28. 	}
    29.  
    30. 	@Test
    31. 	public void testAdd() {
    32. 		new Book(123,"asdf",4567);
    33. 	}
    34.  
    35. 	@Test
    36. 	public void testDel() {
    37. 		Book book2 = new Book(123,"8989",4567);
    38. 		try {
    39. 			bookDao.del(book2);
    40. 		} catch (Exception e) {
    41. 			// TODO Auto-generated catch block
    42. 			e.printStackTrace();
    43. 		}
    44. 	}
    45.  
    46. 	@Test
    47. 	public void testEdit() {
    48. 		Book book2 = new Book(123,"8989",4567);
    49. 		try {
    50. 			bookDao.edit(book2);
    51. 		} catch (Exception e) {
    52. 			// TODO Auto-generated catch block
    53. 			e.printStackTrace();
    54. 		}
    55. 	}
    56.  
    57. }

    运行结果：

     三、通用的增删改

    BaseDao

    1. package com.cdl.util;
    2.  
    3. import java.lang.reflect.Field;
    4. import java.sql.Connection;
    5. import java.sql.ResultSet;
    6. import java.util.ArrayList;
    7. import java.util.List;
    8.  
    9. import com.cdl.entity.Book;
    10.  
    11. /**
    12.  * T代表是实体类，可以是book user goods...
    13.  * 
    14.  * @author 陈冬丽
    15.  *
    16.  * @param <T>
    17.  */
    18. public class BaseDao<T> {
    19. 	/*public List<T> executeQuery(String sql,PageBean pageBean,CallBack<T> callBack) throws Exception{
    20. 		//**
    21. 		 * 1.拿到数据库连接
    22. 		 * 2.拿到域定义对象（preparestatement）
    23. 		 * 3.执行SQL语句
    24. 		 *//*
    25. 		Connection con = DBAccess.getConnection();//连接对象 //重复代码1
    26. 		java.sql.PreparedStatement pst = con.prepareStatement(sql );//执行对象 //重复代码2
    27. 		ResultSet rs = pst.executeQuery();//重复代码3
    28. 		while(rs.next()){
    29. 			//实例化并且赋值加入集合中去
    30. 			list.add(new Book(rs.getInt("bid"), rs.getString("bname"), rs.getFloat("price")));
    31. 		}
    32. 		return list;
    33. 		//查询不同的表，必然要处理不同的结果集
    34. //		接口是调用放来实现
    35. 		return callBack.foreach(rs);
    36. 	}*/
    37. 	
    38. 	
    39. 	public List<T> executeQuery(String sql,PageBean pageBean,CallBack<T> callBack) throws Exception{
    40. //		select * from t_mvc_book where bname like '%圣墟%';
    41. //		从上面得到  select count(1) as n from (select * from t_mvc_book where bname like '%圣墟%') t;
    42. //		目的是为了得到总记录数->得到总页数
    43. //		select * from t_mvc_book where bname like '%圣墟%' limit 10,10;
    44. 		/*
    45. 		  1.拿到数据库连接
    46. 		  2.拿到域定义对象（preparestatement）
    47. 		  3.执行SQL语句*/
    48. 			 
    49. 		Connection con = null;//连接对象 //重复代码1
    50. 		java.sql.PreparedStatement pst = null;//执行对象 //重复代码2
    51. 		ResultSet rs = null;//重复代码3
    52. 		
    53. 		if(pageBean !=null && pageBean.isPagination()) {//分页
    54. 			String countSQL = getCountSQL(sql);
    55. 			con = DBAccess.getConnection();//连接对象 //重复代码1
    56. 			 pst = con.prepareStatement(countSQL);//执行对象 //重复代码2
    57. 			 rs = pst.executeQuery();//重复代码3
    58. 			 if(rs.next()) {
    59. //				 pageBean包含了当前实体类的总记录数
    60. 				 pageBean.setTotal(rs.getString("n"));
    61. 			 }
    62. 			 String pageSQL = getPageSQL(sql,pageBean);
    63. 			 con = DBAccess.getConnection();//连接对象 //重复代码1
    64. 			 pst = con.prepareStatement(pageSQL);//执行对象 //重复代码2
    65. 			 rs = pst.executeQuery();//重复代码3
    66. 		}
    67. 		else {//不分页
    68. 			con = DBAccess.getConnection();//连接对象 //重复代码1
    69. 			pst = con.prepareStatement(sql);//执行对象 //重复代码2
    70. 			rs = pst.executeQuery();//重复代码3
    71. 		}
    72. 		
    73. 		return callBack.foreach(rs);
    74. 		}
    75.  
    76. 	/**
    77. 	 * 拼装第n页的数据
    78. 	 * 
    79. 	 * @param sql
    80. 	 * @param pageBean
    81. 	 * @return
    82. 	 */
    83. 	private String getPageSQL(String sql, PageBean pageBean) {
    84. 		return sql+" limit "+pageBean.getStartIndex()+","+pageBean.getRows();
    85. 	}
    86. 	
    87. 	/**
    88. 	 * 拼装符合条件总记录数的SQL
    89. 	 * @param sql
    90. 	 * @return
    91. 	 */
    92. 	private String getCountSQL(String sql) {
    93. //		select * from t_mvc_book where bname like '%圣墟%';
    94. //		从上面得到  select count(1) as n from (select * from t_mvc_book where bname like '%圣墟%') t;
    95. 		return "select count(1) as n from ("+sql+") t";
    96. 	}
    97. 	
    98. 	public int executeUpdate(String sql,T t,String[] attrs) throws Exception {
    99. 		Connection con = DBAccess.getConnection();
    100. 		java.sql.PreparedStatement pst = con.prepareStatement(sql);
    101. //		将t 的某一个属性对应的值加到pst 对象中
    102. 		for (int i = 0; i < attrs.length; i++) {
    103. 			Field f = t.getClass().getDeclaredField(attrs[i]);
    104. 			f.setAccessible(true);
    105. 			pst.setObject(i + 1,f.get(t));
    106. 		}
    107. 		return pst.executeUpdate();
    108. 	}
    109. 	
    110. }

    BookDao

    1. package com.cdl.dao;
    2.  
    3. import java.sql.Connection;
    4. import java.sql.ResultSet;
    5. import java.sql.SQLException;
    6. import java.util.ArrayList;
    7. import java.util.List;
    8.  
    9. import com.cdl.entity.Book;
    10. import com.cdl.util.BaseDao;
    11. import com.cdl.util.CallBack;
    12. import com.cdl.util.DBAccess;
    13. import com.cdl.util.PageBean;
    14. import com.cdl.util.StringUtils;
    15. import com.mysql.jdbc.PreparedStatement;
    16.  
    17. public class BookDao extends BaseDao<Book>{
    18. 	
    19. 	//查询
    20. 	public List<Book> list(Book book,PageBean pageBean) throws Exception{
    21. 		String sql  = "select * from t_mvc_book where 1=1 ";
    22. 		String bname = book.getBname();
    23. 		if(StringUtils.isNotBlank(bname)) {
    24. 			sql += " and bname like '%"+bname+"%' ";
    25. 		}
    26. 		int bid = book.getBid();
    27. //		前台jsp传递到后台，只要传了就有值，没传就是默认值，默认值就是0
    28. 		if(bid != 0) {
    29. 			sql += " and bid = "+bid;
    30. 		}
    31. 		return super.executeQuery(sql, pageBean, rs -> {
    32. 			List<Book> list = new ArrayList<Book>();
    33. 			try {
    34. 				while(rs.next()) {
    35. 					list.add(new Book(rs.getInt("bid"), rs.getString("bname"), rs.getFloat("price")));
    36. 				}
    37. 			} catch (SQLException e) {
    38. 				// TODO Auto-generated catch block
    39. 				e.printStackTrace();
    40. 			}
    41. 			return list;
    42. 		});
    43. 	}
    44. 	
    45. //	增
    46. //	public int add(Book book) throws Exception {
    47. //		Connection con = DBAccess.getConnection();
    48. //		String sql = "insert into t_mvc_book values(?,?,?)";
    49. //		java.sql.PreparedStatement pst = con.prepareStatement(sql);
    50. //		pst.setObject(1, book.getBid());
    51. //		pst.setObject(2, book.getBname());
    52. //		pst.setObject(3, book.getPrice());
    53. //		return pst.executeUpdate();
    54. //	}
    55. 	public int add(Book book) throws Exception {
    56. 		String sql = "insert into t_mvc_book values(?,?,?)";
    57. 		return super.executeUpdate(sql, book, new String[] {"bid","bname","price"});
    58. 	}
    59. 	
    60. 	
    61. //	删
    62. //	public int del(Book book) throws Exception {
    63. //		Connection con = DBAccess.getConnection();
    64. //		String sql = "delete from t_mvc_book where bid=?";
    65. //		java.sql.PreparedStatement pst = con.prepareStatement(sql);
    66. //		pst.setObject(1, book.getBid());
    67. //		return pst.executeUpdate();
    68. //	}
    69. 	public int del(Book book) throws Exception {
    70. 		String sql = "delete from t_mvc_book where bid=?";
    71. 		return super.executeUpdate(sql, book, new String[] {"bid"});
    72. 	}
    73. 	
    74. 	
    75. //	改
    76. //	public int edit(Book book) throws Exception {
    77. //		Connection con = DBAccess.getConnection();
    78. //		String sql = "update t_mvc_book set bname=?,price=?  where bid=?";
    79. //		java.sql.PreparedStatement pst = con.prepareStatement(sql);
    80. //		pst.setObject(3, book.getBid());
    81. //		pst.setObject(1, book.getBname());
    82. //		pst.setObject(2, book.getPrice());
    83. //		return pst.executeUpdate();
    84. //	}
    85. 	public int edit(Book book) throws Exception {
    86. 		String sql = "update t_mvc_book set bname=?,price=?  where bid=?";
    87. 		return super.executeUpdate(sql, book, new String[] {"bname","price","bid"});
    88. 	}
    89. 	
    90. 	
    91. 	
    92. }

    BookDaoTest

    1. package com.cdl.dao;
    2.  
    3. import static org.junit.Assert.*;
    4.  
    5. import java.util.List;
    6.  
    7. import org.junit.Test;
    8.  
    9. import com.cdl.entity.Book;
    10. import com.cdl.util.PageBean;
    11.  
    12. public class BookDaoTest {
    13. 	
    14. 	private BookDao  bookDao = new BookDao();
    15. 	
    16. 	
    17. 	@Test
    18. 	public void testList() {
    19. 		try {
    20. 			List<Book> list = bookDao.list(new Book(), new PageBean());
    21. 			for (Book book : list) {
    22. 				System.out.println(book);
    23. 			}
    24. 		} catch (Exception e) {
    25. 			// TODO Auto-generated catch block
    26. 			e.printStackTrace();
    27. 		}
    28. 	}
    29.  
    30. 	@Test
    31. 	public void testAdd() {
    32. 		Book book = new Book(123,"asdf",4567);
    33. 		try {
    34. 			bookDao.add(book);
    35. 		} catch (Exception e) {
    36. 			// TODO Auto-generated catch block
    37. 			e.printStackTrace();
    38. 		}
    39. 	}
    40.  
    41. 	@Test
    42. 	public void testDel() {
    43. 		Book book2 = new Book(123,"8989",4567);
    44. 		try {
    45. 			bookDao.del(book2);
    46. 		} catch (Exception e) {
    47. 			// TODO Auto-generated catch block
    48. 			e.printStackTrace();
    49. 		}
    50. 	}
    51.  
    52. 	@Test
    53. 	public void testEdit() {
    54. 		Book book2 = new Book(123,"8989",4567);
    55. 		try {
    56. 			bookDao.edit(book2);
    57. 		} catch (Exception e) {
    58. 			// TODO Auto-generated catch block
    59. 			e.printStackTrace();
    60. 		}
    61. 	}
    62.  
    63. }

    运行增加

     四、查询删除及重复表单提交问题

    建一个com.cdl.web

    BookAction

    1. package com.cdl.web;
    2.  
    3. import java.util.List;
    4.  
    5. import javax.servlet.http.HttpServletRequest;
    6. import javax.servlet.http.HttpServletResponse;
    7.  
    8. import com.cdl.dao.BookDao;
    9. import com.cdl.entity.Book;
    10. import com.cdl.framework.ActionSupport;
    11. import com.cdl.framework.ModelDriven;
    12. import com.cdl.util.PageBean;
    13.  
    14. public class BookAction extends ActionSupport implements ModelDriven<Book>{
    15.  
    16. 	private Book book = new Book();
    17. 	private BookDao bookDao = new BookDao();
    18. 	
    19. 	
    20. 	@Override
    21. 	public Book getModel() {
    22. 		// TODO Auto-generated method stub
    23. 		return book;
    24. 	}
    25. 	
    26. //	增
    27. 	public String add(HttpServletRequest req,HttpServletResponse resp) {
    28. 		try {
    29. 			bookDao.add(book);
    30. 		} catch (Exception e) {
    31. 			// TODO: handle exception
    32. 			e.printStackTrace();
    33. 		}
    34. //		代表跳到查询界面
    35. 		return "toList";
    36. 	}
    37. 	
    38. //	删
    39. 	public String del(HttpServletRequest req,HttpServletResponse resp) {
    40. 		try {
    41. 			bookDao.del(book);
    42. 		} catch (Exception e) {
    43. 			// TODO: handle exception
    44. 			e.printStackTrace();
    45. 		}
    46. //		代表跳到查询界面
    47. 		return "toList";
    48. 	}
    49. 	
    50. //	改
    51. 	public String edit(HttpServletRequest req,HttpServletResponse resp) {
    52. 		try {
    53. 			bookDao.edit(book);
    54. 		} catch (Exception e) {
    55. 			// TODO: handle exception
    56. 			e.printStackTrace();
    57. 		}
    58. //		代表跳到查询界面
    59. 		return "toList";
    60. 	}
    61. 	
    62. //	查
    63. 	public String list(HttpServletRequest req,HttpServletResponse resp) {
    64. 		try {
    65. 			PageBean pageBean = new PageBean();
    66. 			pageBean.setRequest(req);
    67. 			List<Book> list = bookDao.list(book, pageBean);
    68. 			req.setAttribute("list", list);
    69. 			req.setAttribute("pageBean", pageBean);
    70. 		} catch (Exception e) {
    71. 			// TODO: handle exception
    72. 			e.printStackTrace();
    73. 		}
    74. //		执行查询
    75. 		return "list";
    76. 	}
    77. 	
    78. //	跳转到新增/修改界面
    79. 	public String preEdit(HttpServletRequest req,HttpServletResponse resp) {
    80. 		try {
    81. 			int bid = book.getBid();
    82. 			if(bid != 0) {
    83. //				传递bid到后台，有且只能查出一条数据，意味着list集合中也只有一条
    84. 				List<Book> list = bookDao.list(book, null);
    85. 				req.setAttribute("b", list.get(0));
    86. 			}
    87. 		} catch (Exception e) {
    88. 			// TODO: handle exception
    89. 			e.printStackTrace();
    90. 		}
    91. //		代表跳到编辑界面
    92. 		return "toEdit";
    93. 	}
    94. 	
    95. }

    wuyanzu.xml

    1. <?xml version="1.0" encoding="UTF-8"?>
    2. <config>
    3. 	<action path="/book" type="com.cdl.web.BookAction">
    4. 		<forward name="list" path="/bookList.jsp" redirect="false" />
    5. 		<forward name="toEdit" path="/bookEdit.jsp" redirect="false" />
    6. 		<forward name="toList" path="/book.action?methodName=list" redirect="false" />
    7. 	</action>
    8. 	
    9. </config>

    bookList.jsp

    1. <%@ page language="java" contentType="text/html; charset=UTF-8"
    2.     pageEncoding="UTF-8"%>
    3. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    4. <html>
    5. <head>
    6. <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    7. <link
    8. 	href="css/bootstrap.css"
    9. 	rel="stylesheet"> 
    10. <script  src="js/bootstrap.js"></script>
    11. <title>书籍列表</title>
    12. <style type="text/css">
    13. .page-item input {
    14. 	padding: 0;
    15. 	width: 40px;
    16. 	height: 100%;
    17. 	text-align: center;
    18. 	margin: 0 6px;
    19. }
    20.  
    21. .page-item input, .page-item b {
    22. 	line-height: 38px;
    23. 	float: left;
    24. 	font-weight: 400;
    25. }
    26.  
    27. .page-item.go-input {
    28. 	margin: 0 10px;
    29. }
    30. </style>
    31. </head>
    32. <body>
    33. 	 <form class="form-inline"
    34. 		action="${pageContext.request.contextPath }/book.action?methodName=list" method="post">
    35. 		<div class="form-group mb-2">
    36. 			<input type="text" class="form-control-plaintext" name="bname"
    37. 				placeholder="请输入书籍名称">
    38. 		</div>
    39. 		<button type="submit" class="btn btn-primary mb-2">查询</button>
    40. 	</form>
    41.  
    42. 	<table class="table table-striped">
    43. 		<thead>
    44. 			<tr>
    45. 				<th scope="col">书籍ID</th>
    46. 				<th scope="col">书籍名</th>
    47. 				<th scope="col">价格</th>
    48. 			</tr>
    49. 		</thead>
    50. 		<tbody>
    51. 		<c:forEach items="${list}" var="book">
    52. 			<tr>
    53. 				<td>${book.bid}</td>
    54. 				<td>${book.bname}</td>
    55. 				<td>${book.price}</td>
    56. 			</tr>
    57. 		</c:forEach>
    58.  
    59. 		</tbody>
    60. 	</table>
    61. 	
    62. 	<z:page pageBean="${pageBen}"></z:page> 
    63.  
    64. </body>
    65. </html>

     bookList.jsp

    1. <%@ page language="java" contentType="text/html; charset=UTF-8"
    2.     pageEncoding="UTF-8"%>
    3. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    4. <html>
    5. <head>
    6. <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    7. <link
    8. 	href="css/bootstrap.css"
    9. 	rel="stylesheet"> 
    10. <script  src="js/bootstrap.js"></script>
    11. <title>书籍列表</title>
    12. <style type="text/css">
    13. .page-item input {
    14. 	padding: 0;
    15. 	width: 40px;
    16. 	height: 100%;
    17. 	text-align: center;
    18. 	margin: 0 6px;
    19. }
    20.  
    21. .page-item input, .page-item b {
    22. 	line-height: 38px;
    23. 	float: left;
    24. 	font-weight: 400;
    25. }
    26.  
    27. .page-item.go-input {
    28. 	margin: 0 10px;
    29. }
    30. </style>
    31. </head>
    32. <body>
    33. 	 <form class="form-inline"
    34. 		action="${pageContext.request.contextPath }/book.action?methodName=list" method="post">
    35. 		<div class="form-group mb-2">
    36. 			<input type="text" class="form-control-plaintext" name="bname"
    37. 				placeholder="请输入书籍名称">
    38. 		</div>
    39. 		<button type="submit" class="btn btn-primary mb-2">查询</button>
    40. 	</form>
    41.  
    42. 	<table class="table table-striped">
    43. 		<thead>
    44. 			<tr>
    45. 				<th scope="col">书籍ID</th>
    46. 				<th scope="col">书籍名</th>
    47. 				<th scope="col">价格</th>
    48. 				<th scope="col">操作</th>
    49. 			</tr>
    50. 		</thead>
    51. 		<tbody>
    52. 		<c:forEach items="${list}" var="book">
    53. 			<tr>
    54. 				<td>${book.bid}</td>
    55. 				<td>${book.bname}</td>
    56. 				<td>${book.price}</td>
    57. 				<td>
    58. 					<a href="${pageContext.request.contextPath}/book.action?methodName=preEdit?bid=${book.bid}">编辑</a>
    59. 					<a href="${pageContext.request.contextPath}/book.action?methodName=del?bid=${book.bid}">删除</a>
    60. 				</td>
    61. 			</tr>
    62. 		</c:forEach>
    63.  
    64. 		</tbody>
    65. 	</table>
    66. 	
    67. 	<z:page pageBean="${pageBean}"></z:page> 
    68.  
    69. </body>
    70. </html>

    效果图：

     当点击删除后

     因为地址栏将参数又带回去了

    将wuyanzu.xml的配置的提交方式改变

    1. <?xml version="1.0" encoding="UTF-8"?>
    2. <config>
    3. 	<action path="/book" type="com.cdl.web.BookAction">
    4. 		<forward name="list" path="/bookList.jsp" redirect="false" />
    5. 		<forward name="toEdit" path="/bookEdit.jsp" redirect="false" />
    6. 		<forward name="toList" path="/book.action?methodName=list" redirect="true" />
    7. 	</action>
    8. 	
    9. </config>

    五、新增修改的前端实现

    新增界面

    1. <%@ page language="java" contentType="text/html; charset=UTF-8"
    2.     pageEncoding="UTF-8"%>
    3. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    4. <html>
    5. <head>
    6. <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    7. <title>Insert title here</title>
    8. </head>
    9. <body>
    10. 	<form action="${pageContext.request.contextPath }/book.action?methodName=${empty b ? 'add' : 'edit'}" method="post">
    11. 		bid:<input type="text" name="bid" value="${b.bid}">
    12. 		bname:<input type="text" name="bname" value="${b.bname}">
    13. 		price:<input type="text" name="price" value="${b.price}">
    14. 		<input type="submit" vaule="提交">
    15. 	</form>
    16. </body>
    17. </html>

    效果：

     

    此时的bookList.jsp

    1. <%@ page language="java" contentType="text/html; charset=UTF-8"
    2.     pageEncoding="UTF-8"%>
    3. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
    4. <html>
    5. <head>
    6. <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    7. <link
    8. 	href="css/bootstrap.css"
    9. 	rel="stylesheet"> 
    10. <script  src="js/bootstrap.js"></script>
    11. <title>书籍列表</title>
    12. <style type="text/css">
    13. .page-item input {
    14. 	padding: 0;
    15. 	width: 40px;
    16. 	height: 100%;
    17. 	text-align: center;
    18. 	margin: 0 6px;
    19. }
    20.  
    21. .page-item input, .page-item b {
    22. 	line-height: 38px;
    23. 	float: left;
    24. 	font-weight: 400;
    25. }
    26.  
    27. .page-item.go-input {
    28. 	margin: 0 10px;
    29. }
    30. </style>
    31. </head>
    32. <body>
    33. 	 <form class="form-inline"
    34. 		action="${pageContext.request.contextPath }/book.action?methodName=list" method="post">
    35. 		<div class="form-group mb-2">
    36. 			<input type="text" class="form-control-plaintext" name="bname"
    37. 				placeholder="请输入书籍名称">
    38. 		</div>
    39. 		<button type="submit" class="btn btn-primary mb-2">查询</button>
    40. 		<a class="btn btn-primary mb-2"  href="${pageContext.request.contextPath}/book.action?methodName=preEdit">新增</a>
    41. 	</form>
    42.  
    43. 	<table class="table table-striped">
    44. 		<thead>
    45. 			<tr>
    46. 				<th scope="col">书籍ID</th>
    47. 				<th scope="col">书籍名</th>
    48. 				<th scope="col">价格</th>
    49. 				<th scope="col">操作</th>
    50. 			</tr>
    51. 		</thead>
    52. 		<tbody>
    53. 		<c:forEach items="${list}" var="book">
    54. 			<tr>
    55. 				<td>${book.bid}</td>
    56. 				<td>${book.bname}</td>
    57. 				<td>${book.price}</td>
    58. 				<td>
    59. 					<a href="${pageContext.request.contextPath}/book.action?methodName=preEdit?bid=${book.bid}">编辑</a>
    60. 					<a href="${pageContext.request.contextPath}/book.action?methodName=del?bid=${book.bid}">删除</a>
    61. 				</td>
    62. 			</tr>
    63. 		</c:forEach>
    64.  
    65. 		</tbody>
    66. 	</table>
    67. 	
    68. 	<z:page pageBean="${pageBean}"></z:page> 
    69.  
    70. </body>
    71. </html>

     注意：过滤器

    1. package com.cdl.util;
    2.  
    3. import java.io.IOException;
    4. import java.util.Iterator;
    5. import java.util.Map;
    6. import java.util.Set;
    7.  
    8. import javax.servlet.Filter;
    9. import javax.servlet.FilterChain;
    10. import javax.servlet.FilterConfig;
    11. import javax.servlet.ServletException;
    12. import javax.servlet.ServletRequest;
    13. import javax.servlet.ServletResponse;
    14. import javax.servlet.annotation.WebFilter;
    15. import javax.servlet.http.HttpServletRequest;
    16. import javax.servlet.http.HttpServletResponse;
    17.  
    18. /**
    19.  * 中文乱码处理
    20.  * 
    21.  */
    22. @WebFilter("*.action")
    23. public class EncodingFiter implements Filter {
    24.  
    25. 	private String encoding = "UTF-8";// 默认字符集
    26.  
    27. 	public EncodingFiter() {
    28. 		super();
    29. 	}
    30.  
    31. 	public void destroy() {
    32. 	}
    33.  
    34. 	public void doFilter(ServletRequest request, ServletResponse response,
    35. 			FilterChain chain) throws IOException, ServletException {
    36. 		HttpServletRequest req = (HttpServletRequest) request;
    37. 		HttpServletResponse res = (HttpServletResponse) response;
    38.  
    39. 		// 中文处理必须放到 chain.doFilter(request, response)方法前面
    40. 		res.setContentType("text/html;charset=" + this.encoding);
    41. 		if (req.getMethod().equalsIgnoreCase("post")) {
    42. 			req.setCharacterEncoding(this.encoding);
    43. 		} else {
    44. 			Map map = req.getParameterMap();// 保存所有参数名=参数值(数组)的Map集合
    45. 			Set set = map.keySet();// 取出所有参数名
    46. 			Iterator it = set.iterator();
    47. 			while (it.hasNext()) {
    48. 				String name = (String) it.next();
    49. 				String[] values = (String[]) map.get(name);// 取出参数值[注：参数值为一个数组]
    50. 				for (int i = 0; i < values.length; i++) {
    51. 					values[i] = new String(values[i].getBytes("ISO-8859-1"),
    52. 							this.encoding);
    53. 				}
    54. 			}
    55. 		}
    56.  
    57. 		chain.doFilter(request, response);
    58. 	}
    59.  
    60. 	public void init(FilterConfig filterConfig) throws ServletException {
    61. 		String s = filterConfig.getInitParameter("encoding");// 读取web.xml文件中配置的字符集
    62. 		if (null != s && !s.trim().equals("")) {
    63. 			this.encoding = s.trim();
    64. 		}
    65. 	}
    66.  
    67. }

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  • 原文地址：https://blog.csdn.net/weixin_62735525/article/details/125513439