1.开始页面（查询数据）
1 <%@page import="com.zdsofe.work.Student"%> 2 <%@page import="java.util.List"%> 3 <%@page import="com.zdsofe.work.ReadData"%> 4 <%@ page language="java" contentType="text/html; charset=UTF-8" 5 pageEncoding="UTF-8"%> 6 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 7 <html> 8 <head> 9 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 10 <title>Insert title here</title> 11 </head> 12 <body> 13 <% ReadData rd=new ReadData(); 14 List<Student> list= rd.findInfo(); 15 %> 16 17 <table border="1"> 18 <tr> 19 <th>序号</th> 20 <th>名字</th> 21 <th>密码</th> 22 <th>操作</th> 23 </tr> 24 25 26 <% 27 for(int i=0;i<list.size();i++) 28 { 29 %> 30 <tr> 31 <td><%=list.get(i).getId()%></td> 32 <td><%=list.get(i).getUserName()%></td> 33 <td><%=list.get(i).getMima()%></td> 34 <td><a href="../servlet?userN=<%=list.get(i).getUserName()%>">修改</a> 35 <a href="../DeleteServlet?userI=<%=list.get(i).getId()%>">删除</a> 36 </td> 37 </tr> 38 <% 39 } 40 %> 41 42 </table> 43 </body> 44 </html>
2.获取数据的servlet
1 package com.zdsofe.work; 2 3 import java.io.IOException; 4 import java.sql.ResultSet; 5 import java.sql.SQLException; 6 import java.sql.Statement; 7 8 import javax.servlet.ServletException; 9 import javax.servlet.annotation.WebServlet; 10 import javax.servlet.http.HttpServlet; 11 import javax.servlet.http.HttpServletRequest; 12 import javax.servlet.http.HttpServletResponse; 13 import javax.servlet.http.HttpSession; 14 15 import com.zdsofe.util.DBUtil; 16 17 /** 18 * Servlet implementation class servlet 19 */ 20 @WebServlet("/servlet") 21 public class servlet extends HttpServlet { 22 private static final long serialVersionUID = 1L; 23 24 /** 25 * @see HttpServlet#HttpServlet() 26 */ 27 public servlet() { 28 super(); 29 // TODO Auto-generated constructor stub 30 } 31 32 /** 33 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) 34 */ 35 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 36 //解决乱码问题 37 request.setCharacterEncoding("utf-8"); 38 response.setCharacterEncoding("utf-8"); 39 response.setContentType("text/html charset=utf-8"); 40 41 //获取用户名： 42 String userName = request.getParameter("userN"); 43 44 //根据用户名查询某一条用户信息 45 Student stu=ReadData.findUserByName(userName); 46 HttpSession session = request.getSession(); 47 session.setAttribute("user", stu); 48 session.setAttribute("title", "修改用户"); 49 response.sendRedirect("/webProject2/pages/edit.jsp"); 50 } 51 52 /** 53 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) 54 */ 55 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 56 57 58 } 59 60 }
3.修改页面
1 <%@page import="com.zdsofe.work.Student"%> 2 <%@ page language="java" contentType="text/html; charset=UTF-8" 3 pageEncoding="UTF-8"%> 4 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 5 <html> 6 <head> 7 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 8 <title>Insert title here</title> 9 </head> 10 11 <% 12 //获取用户信息 13 Student stu=(Student)session.getAttribute("user"); 14 %> 15 <body> 16 17 <form action="../EditServlet" method="get"> 18 19 用户名：<input type="text" name="userName" value="<%=stu.getUserName()%>"><br/> 20 密码：<input type="password" name="mima" value="<%=stu.getMima()%>"><br/> 21 <button type="submit">提交</button> 22 23 </form> 24 25 </body> 26 </html>
4.修改数据的servlet
1 package com.zdsofe.work; 2 3 import java.io.IOException; 4 import java.lang.reflect.InvocationTargetException; 5 import java.util.Enumeration; 6 import java.util.HashMap; 7 import java.util.Map; 8 9 import javax.servlet.ServletException; 10 import javax.servlet.annotation.WebServlet; 11 import javax.servlet.http.HttpServlet; 12 import javax.servlet.http.HttpServletRequest; 13 import javax.servlet.http.HttpServletResponse; 14 15 import org.apache.commons.beanutils.BeanUtils; 16 17 /** 18 * Servlet implementation class EditServlet 19 */ 20 @WebServlet("/EditServlet") 21 public class EditServlet extends HttpServlet { 22 private static final long serialVersionUID = 1L; 23 24 /** 25 * @see HttpServlet#HttpServlet() 26 */ 27 public EditServlet() { 28 super(); 29 // TODO Auto-generated constructor stub 30 } 31 32 /** 33 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) 34 */ 35 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 36 //请求和响应页面的编码格式修改 37 38 request.setCharacterEncoding("UTF-8"); 39 response.setCharacterEncoding("utf-8"); 40 response.setContentType("text/html charset=utf-8"); 41 /*//获取表单中的所用控件name属性 42 Enumeration<String> en = request.getParameterNames(); 43 Map<String, Object> mapObj = new HashMap<>(); 44 //实例化一个Student对象 45 Student stu=new Student(); 46 while(en.hasMoreElements()) 47 { 48 String rs = en.nextElement(); 49 mapObj.put(rs, request.getParameter("rs")); 50 } 51 try { 52 BeanUtils.populate(stu, mapObj); 53 54 55 } catch (IllegalAccessException | InvocationTargetException e) { 56 e.printStackTrace(); 57 }*/ 58 String name=request.getParameter("userName"); 59 String mima=request.getParameter("mima"); 60 Student stu=new Student(name,mima); 61 //根据条件修改用户信息，调用执行sql方法 62 63 int upResult = ReadData.update(stu); 64 65 if(upResult==1) 66 { 67 response.sendRedirect(request.getContextPath()+"/pages/student.jsp"); 68 } 69 70 } 71 72 /** 73 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) 74 */ 75 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 76 // TODO Auto-generated method stub 77 } 78 79 }
5.删除数据的servlet
1 package com.zdsofe.work; 2 3 import java.io.IOException; 4 import java.sql.SQLException; 5 import java.sql.Statement; 6 7 import javax.servlet.ServletException; 8 import javax.servlet.annotation.WebServlet; 9 import javax.servlet.http.HttpServlet; 10 import javax.servlet.http.HttpServletRequest; 11 import javax.servlet.http.HttpServletResponse; 12 13 import com.zdsofe.util.DBUtil; 14 15 /** 16 * Servlet implementation class DeleteServlet 17 */ 18 @WebServlet("/DeleteServlet") 19 public class DeleteServlet extends HttpServlet { 20 private static final long serialVersionUID = 1L; 21 22 /** 23 * @see HttpServlet#HttpServlet() 24 */ 25 public DeleteServlet() { 26 super(); 27 // TODO Auto-generated constructor stub 28 } 29 30 /** 31 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) 32 */ 33 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 34 35 //获取要删除的用户ID 36 String userId = request.getParameter("userI"); 37 //删除的sql语句 38 String sql = "delete from denglu where id = "+userId+""; 39 40 try { 41 Statement stam= DBUtil.getConnection().createStatement(); 42 stam.executeUpdate(sql); 43 } catch (SQLException e) { 44 // TODO Auto-generated catch block 45 e.printStackTrace(); 46 } 47 response.sendRedirect(request.getContextPath()+"/pages/student.jsp"); 48 } 49 50 /** 51 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) 52 */ 53 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 54 // TODO Auto-generated method stub 55 } 56 57 }
6.javaBean(实体类)
1 package com.zdsofe.work; 2 3 public class Student { 4 public String id; 5 public String userName; 6 public String mima; 7 8 public Student(String id, String userName, String mima) { 9 super(); 10 this.id = id; 11 this.userName = userName; 12 this.mima = mima; 13 } 14 15 public Student(String userName, String mima) { 16 17 this.userName = userName; 18 this.mima = mima; 19 } 20 21 public Student() { 22 super(); 23 } 24 25 public String getId() { 26 return id; 27 } 28 public void setId(String id) { 29 this.id = id; 30 } 31 public String getUserName() { 32 return userName; 33 } 34 public void setUserName(String userName) { 35 this.userName = userName; 36 } 37 public String getMima() { 38 return mima; 39 } 40 public void setMima(String mima) { 41 this.mima = mima; 42 } 43 44 45 46 47 }
7.方法
1 package com.zdsofe.work; 2 3 import java.sql.ResultSet; 4 import java.sql.SQLException; 5 import java.sql.Statement; 6 import java.util.ArrayList; 7 import java.util.List; 8 9 import com.zdsofe.util.DBUtil; 10 11 12 13 public class ReadData { 14 15 //查询信息 16 public static List<Student> findInfo() { 17 18 19 List <Student>list=new ArrayList<>(); 20 //调用连接并创建SQL语句 21 try { 22 Statement stam= DBUtil.getConnection().createStatement(); 23 String sql="SELECT id,userName,mima FROM denglu;"; 24 ResultSet rs=stam.executeQuery(sql); 25 while(rs.next()) 26 { 27 String id=rs.getString("id"); 28 String userName=rs.getString("userName"); 29 String mima=rs.getString("mima"); 30 Student stu=new Student(id,userName,mima); 31 list.add(stu); 32 } 33 34 } catch (SQLException e) { 35 e.printStackTrace(); 36 37 } 38 return list; 39 } 40 41 /* 根据用户名查询用户信息 42 * @param userName 43 * @return 44 */ 45 public static Student findUserByName(String userName) 46 { 47 Student stu=null; 48 //输出查询sql 49 String sql = "select * from denglu t where t.userName=‘"+userName+"‘"; 50 try { 51 //调用连接并创建SQL语句 52 Statement stam= DBUtil.getConnection().createStatement(); 53 54 ResultSet rs=stam.executeQuery(sql); 55 if(rs.next()) 56 { 57 String id=rs.getString("id"); 58 String name=rs.getString("userName"); 59 String mima=rs.getString("mima"); 60 stu=new Student(id,name,mima); 61 } 62 63 } catch (SQLException e) { 64 e.printStackTrace(); 65 66 } 67 return stu; 68 } 69 70 /** 71 * 根据编码修改用户信息 72 * @param user 73 * @return 74 */ 75 public static int update(Student stu) 76 { 77 //执行sql的结果 78 int result = 0; 79 //更新sql 80 81 String sql = "update denglu t set t.mima = ‘"+stu.getMima()+"‘ where t.userName =‘"+stu.getUserName()+"‘"; 82 try { 83 Statement stam= DBUtil.getConnection().createStatement(); 84 result=stam.executeUpdate(sql); 85 86 } catch (SQLException e) { 87 e.printStackTrace(); 88 } 89 90 91 return result; 92 } 93 }
8.连接数据库的包装类
1 package com.zdsofe.util; 2 3 import java.sql.Connection; 4 import java.sql.DriverManager; 5 import java.sql.SQLException; 6 7 public class DBUtil { 8 private static String DRIVER="com.mysql.jdbc.Driver"; 9 private static String URL="jdbc:mysql://localhost:3306/mysql"; 10 private static String user="root"; 11 private static String key="775297"; 12 public static Connection conn; 13 14 //加载驱动 15 static{ 16 try { 17 Class.forName(DRIVER); 18 } catch (ClassNotFoundException e) { 19 e.printStackTrace(); 20 } 21 } 22 //连接数据库 23 public static Connection getConnection(){ 24 try { 25 conn = DriverManager.getConnection(URL, user, key); 26 } catch (SQLException e) { 27 e.printStackTrace(); 28 } 29 return conn; 30 } 31 }
JavaBean+servlet+jsp——>对数据进行增删改查
原文：http://www.cnblogs.com/zclqian/p/7248350.html
