目录结构:
先创建库。
写前端吧。
******************Jsp**********************
login.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title><style type="text/CSS">body { background-image:url('images/yellowbg.png'); background-size: cover; /* 图片平铺拉伸，适应屏幕 */}h1{ /* 标题居中 */ margin:100px auto; text-align: center;}form{ /* 表单居中 */ width:300px; height:220px; margin: 100px auto;}.item{ /* item与itemV的设定纯粹是为了让出入框左对齐，名字右对齐 */ width:80px; display:inline-block; text-align: right;}.itemV{ width:180px; display:inline-block; text-align: right;}#btn{ /* 按钮居中 */ margin-left: 80px;}</style></head><body> <h1>欢迎登录学生管理系统！</h1> <form action="loginServlet" method="post"> <span class="item">用户名:</span> <input type="text" name="username" /></span><br><br> <span class="item">密码:</span> <input type="text" name="passWord" /></span><br><br><br> <div id="btn"> <input type="submit" value="登录" /> <input type="reset" value="重置" /> </div> </form> </body></html>welcome.jsp
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title><style>body { background-image:url('images/greenbg.png'); background-size: cover;}h1{ margin:150px auto; text-align: center;}span{ color:red; font-family:fantasy;}</style></head><body> <h1>登录成功，欢迎<span><%=request.getAttribute("username") %></span>来到学生管理系统！</h1> <center><p>5秒钟后系统会自动跳转到查看全部学生信息页面...</p></center> <%response.setHeader("refresh","5;url=findAllServlet"); %></body></html>error.jsp<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title><style>body { background-image:url('images/yellowbg.png'); background-size: cover;}h1{ margin:150px auto; text-align: center;}span{ color:red; font-family:fantasy;}</style></head><body> <h1>登录失败，<span><%=request.getAttribute("username") %></span>的用户名或者密码错误！</h1> <center><p>5秒钟后系统会自动跳转到登录页面...</p></center> <%response.setHeader("refresh","5;url=login.jsp"); %></body></html>listStudent.jsp<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><%@page import="java.util.List" %><%@page import="com.bean.Student" %><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title><style>body { background-image:url('images/greenbg.png'); background-size: cover; /* 图片平铺拉伸，适应屏幕 */}h1{ margin:50px auto; text-align: center;}table { width:600px; margin:50px auto; border-collapse: collapse; text-align: center;}table,th,td{border:1px solid black;}th{height:50px;}a:link {color:black;} /* 未访问链接*/a:visited {color:black;} a:hover {color:#f00;} /* 鼠标移动到链接上 */a:active {color:#f60;} /* 已点击 */#toAdd{ text-align: center;}</style></head><body> <h1>欢迎来到查看学生页面</h1> <table style="border: 1px"> <tr> <th>ID</th> <th>username</th> <th>password</th> <th>sex</th> <th>address</th> <th colspan="3">操作</th> </tr> <% List<Student> ss = (List<Student>)request.getAttribute("ss"); for(Student s : ss){ %> <tr> <td><%=s.getId() %></td> <td><%=s.getUsername() %></td> <td><%=s.getPassword() %></td> <td><%=s.getSex() %></td> <td><%=s.getAddress() %></td> <td colspan="3"> <a href="update.jsp?id=<%=s.getId()%>&username=<%=s.getUsername()%>&password=<%=s.getPassword()%>&sex=<%=s.getSex()%>&address=<%=s.getAddress()%>">修改</a> <a href="deleteServlet?id=<%=s.getId()%>" onclick="return confirm('确定删除？')">删除</a> </td> </tr> <% } %> </table> <div id="toAdd"><a href="add.jsp">增加学生</a></div> </body></html>add.jsp<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><%@page import="com.bean.Student" %><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title><style type="text/css">body { background-image:url('images/greenbg.png'); background-size: cover;}h1{ margin:50px auto; text-align: center;}form{ width:310px; margin: 100px auto;}.item{ color:red; width:100px; display:inline-block; text-align:right;}.btn{ width:50px;}</style></head><body> <h1>欢迎来到新增学生页面</h1> <form action="addServlet" method="post"> <span class="item">ID：</span> <span><input type="text" name="id" /></span><br> <span class="item">username：</span> <span><input type="text" name="username" /></span><br> <span class="item">password：</span> <span><input type="text" name="password" /></span><br> <span class="item">sex：</span> <span><input type="text" name="sex" /></span><br> <span class="item">address：</span> <span><input type="text" name="address" /></span><br> <br><br> <center> <input class="btn" type="submit" value="提交" /> <input class="btn" type="reset" value="重置" /> </center> </form></body></html>update.jsp<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%><%@page import="com.bean.Student" %><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>Insert title here</title><style type="text/css">body { background-image:url('images/greenbg.png'); background-size: cover;}h1{ margin:50px auto; text-align: center;}form{ width:310px; margin: 100px auto;}.item{ color:red; width:100px; display:inline-block; text-align:right;}.btn{ width:50px;}</style></head><body> <% String id = request.getParameter("id"); String username = request.getParameter("username"); String password = request.getParameter("password"); String sex = request.getParameter("sex"); String address = request.getParameter("address"); %> <!-- id是唯一定位元素的标识符，不能修改，但可以显示给人看，此时不要用disabled限制别人访问，因为 它会使id的name连同value都作废，不能提交给servlet；用read-only，它可以提交。 --> <h1>欢迎来到修改学生信息页面</h1> <form action="updateServlet" method="post"> <span class="item">ID：</span> <span><input type="text" name="id" value="<%=id %>" readonly="readonly"/></span><br> <span class="item">username：</span> <span><input type="text" name="username" value="<%=username %>" /></span><br> <span class="item">password：</span> <span><input type="text" name="password" value="<%=password %>" /></span><br> <span class="item">sex：</span> <span><input type="text" name="sex" value="<%=sex %>" /></span><br> <span class="item">address：</span> <span><input type="text" name="address" value="<%=address %>" /></span><br> <br><br> <center> <input class="btn" type="submit" value="提交" /> <input class="btn" type="reset" value="重置" /> </center> </form></body></html>******************web.xml**********************
web.xml
<?xml version="1.0" encoding="UTF-8"?><web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <welcome-file-list> <welcome-file>login.jsp</welcome-file> </welcome-file-list> <servlet> <servlet-name>UpdateServlet</servlet-name> <servlet-class>com.servlet.UpdateServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>UpdateServlet</servlet-name> <url-pattern>/updateServlet</url-pattern> </servlet-mapping> <servlet> <servlet-name>FindAllServlet</servlet-name> <servlet-class>com.servlet.FindAllServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>FindAllServlet</servlet-name> <url-pattern>/findAllServlet</url-pattern> </servlet-mapping> <servlet> <servlet-name>LoginServlet</servlet-name> <servlet-class>com.servlet.LoginServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>LoginServlet</servlet-name> <url-pattern>/loginServlet</url-pattern> </servlet-mapping> <servlet> <servlet-name>ListServlet</servlet-name> <servlet-class>com.servlet.ListServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>ListServlet</servlet-name> <url-pattern>/listServlet</url-pattern> </servlet-mapping> <servlet> <servlet-name>DeleteServlet</servlet-name> <servlet-class>com.servlet.DeleteServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>DeleteServlet</servlet-name> <url-pattern>/deleteServlet</url-pattern> </servlet-mapping> <servlet> <servlet-name>AddServlet</servlet-name> <servlet-class>com.servlet.AddServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>AddServlet</servlet-name> <url-pattern>/addServlet</url-pattern> </servlet-mapping> </web-app>******************Bean类**********************
Student.java
package com.bean;public class Student { PRivate int id; private String username; private String password; private int sex; private String address; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public int getSex() { return sex; } public void setSex(int sex) { this.sex = sex; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; }}******************Servlet类**********************LoginServlet.java
package com.servlet;import java.io.IOException;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class LoginServlet extends HttpServlet { protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //第一步，先把字符集设定成utf-8，否则万一浏览器送来的是中文就会出现乱码 request.setCharacterEncoding("utf-8"); //先把浏览器输入的用户名、密码拿出来。 String un = request.getParameter("username"); String pw = request.getParameter("password"); //把用户名设置到request的属性里，这样得会儿跳转到欢迎或者错误页面时好知道叫什么 request.setAttribute("username", un); //此时开始在数据库中搜寻有没有同时满足用户名、密码的行，有就对，没有就错： //先加载lib目录下的java-connect-MySQL.jar驱动包 try { Class.forName("com.mysql.jdbc.Driver"); //选择驱动类，连接地址、账号密码，连接MySQL String driverClass="com.mysql.jdbc.Driver"; String url="jdbc:mysql://localhost:3306/school?useUnicode=true&characterEncoding=utf-8"; String sqlusername="root"; String sqlpassword="root"; Connection conn = DriverManager.getConnection(url, sqlusername, sqlpassword); //编写SQL语句，这里不要用statement了，换用preparedstatement，因为 //preparedstatement可以设置？为形参，然后set各个形参的实际值，statement没有此 //功能。最后执行更新语句。 //此外，？不要加单双引号，否则报错java.sql.SQLException: Parameter index out of range (0 < 1 ). String sql = "select * from student where username = ? and password = ?"; PreparedStatement ps = conn.prepareStatement(sql); ps.setString(1, un); ps.setString(2, pw); ResultSet rs=ps.executeQuery(); if(rs.next()){ request.getRequestDispatcher("welcome.jsp").forward(request, response); }else{ request.getRequestDispatcher("error.jsp").forward(request, response); } } catch (ClassNotFoundException | SQLException e) { e.printStackTrace(); } } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }FindAllServlet.java
package com.servlet;import java.io.IOException;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.ArrayList;import java.util.List;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.bean.Student;public class FindAllServlet extends HttpServlet{ //重写doGet方法 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { try { //先加载lib目录下的java-connect-mysql.jar驱动包 Class.forName("com.mysql.jdbc.Driver"); //选择驱动类，连接地址、账号密码，连接MySQL String driverClass="com.mysql.jdbc.Driver"; String url="jdbc:mysql://localhost:3306/school?useUnicode=true&characterEncoding=utf-8"; String sqlusername="root"; String sqlpassword="root"; Connection conn = DriverManager.getConnection(url, sqlusername, sqlpassword); //编写SQL语句，执行，拿到结果集 String sql = "select * from student"; Statement statement = conn.createStatement(); ResultSet resultSet = statement.executeQuery(sql); //把结果集的东西倒进ArrayList List<Student> ss = new ArrayList<Student>(); while(resultSet.next()){ Student s = new Student(); s.setId(resultSet.getInt("id")); s.setUsername(resultSet.getString("username")); s.setPassword(resultSet.getString("password")); s.setSex(resultSet.getInt("sex")); s.setAddress(resultSet.getString("address")); //后台打印，试看有没有拿到 /*String ms = resultSet.getInt("id")+resultSet.getString("username"); System.out.println(ms);*/ ss.add(s); } //ArrayList放进request的属性里，这样jsp页面就能request.getAttribute("ss") //拿出ArrayList了。 request.setAttribute("ss", ss); resultSet.close(); statement.close(); } catch (SQLException | ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } //跳转到显示页面 request.getRequestDispatcher("listStudent.jsp") .forward(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }AddServlet.java
package com.servlet;import java.io.IOException;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.ArrayList;import java.util.List;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.bean.Student;public class AddServlet extends HttpServlet{ //重写doGet方法 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); //从jsp页面获取要添加的新对象的各项值 int id = Integer.valueOf(request.getParameter("id")); String username = request.getParameter("username"); String password = request.getParameter("password"); int sex = Integer.valueOf(request.getParameter("sex")); String address = request.getParameter("address"); try { //先加载lib目录下的java-connect-mysql.jar驱动包 Class.forName("com.mysql.jdbc.Driver"); //选择驱动类，连接地址、账号密码，连接MySQL String driverClass="com.mysql.jdbc.Driver"; String url="jdbc:mysql://localhost:3306/school?useUnicode=true&characterEncoding=utf-8"; String sqlusername="root"; String sqlpassword="root"; Connection conn = DriverManager.getConnection(url, sqlusername, sqlpassword); //编写SQL语句，这里不要用statement了，换用preparedstatement，因为 //preparedstatement可以设置？为形参，然后set各个形参的实际值，statement没有此 //功能。最后执行更新语句。 //此外，？不要加单双引号，否则报错java.sql.SQLException: Parameter index out of range (0 < 1 ). String sql = "insert into student values("+id+",'"+username+"','"+password+"',"+sex+",'"+address+"')"; PreparedStatement ps = conn.prepareStatement(sql); ps.executeUpdate(); //关闭连接 ps.close(); conn.close(); } catch (SQLException | ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } //跳转到显示页面 response.sendRedirect("findAllServlet"); /*request.getRequestDispatcher("listStudent.jsp") .forward(request, response); */ } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }DeleteServlet.java
package com.servlet;import java.io.IOException;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.ArrayList;import java.util.List;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.bean.Student;/** * 写DeleteServlet时遇到极大的困难，代码都对，前台jsp里<a href="deleteServlet?id=<%=s.getId()%>">删除</a> * 对，后台接收id的值，然后删除也对，但是就是进不来servlet，前台提示找不到404。后来关了服务器、清理、重启、前台改了若干数据、删除，问题好了。 * 可能是服务器没有重启的原因，也有可能是前台的缓存造成的找不到，仅仅刷新是不够的，缓存没有变，必须跳转页面，才有新缓存。 * @author Administrator * */public class DeleteServlet extends HttpServlet{ //重写doGet方法 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //从jsp页面获取要修改的元素的id和各项修改后的值 int id = Integer.valueOf(request.getParameter("id")); try { //先加载lib目录下的java-connect-mysql.jar驱动包 Class.forName("com.mysql.jdbc.Driver"); //选择驱动类，连接地址、账号密码，连接MySQL String driverClass="com.mysql.jdbc.Driver"; String url="jdbc:mysql://localhost:3306/school?useUnicode=true&characterEncoding=utf-8"; String sqlusername="root"; String sqlpassword="root"; Connection conn = DriverManager.getConnection(url, sqlusername, sqlpassword); //编写SQL语句，这里不要用statement了，换用preparedstatement，因为 //preparedstatement可以设置？为形参，然后set各个形参的实际值，statement没有此 //功能。最后执行更新语句。 //此外，？不要加单双引号，否则报错java.sql.SQLException: Parameter index out of range (0 < 1 ). String sql = "delete from student where id = ?"; PreparedStatement ps = conn.prepareStatement(sql); ps.setInt(1, id); ps.executeUpdate(); //关闭连接 ps.close(); conn.close(); } catch (SQLException | ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } //跳转到显示页面 response.sendRedirect("findAllServlet"); /*request.getRequestDispatcher("listStudent.jsp") .forward(request, response); */ } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }UpdateServlet.java
package com.servlet;import java.io.IOException;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.ArrayList;import java.util.List;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.bean.Student;public class UpdateServlet extends HttpServlet{ //重写doGet方法 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("utf-8"); //从jsp页面获取要修改的元素的id和各项修改后的值 int id = Integer.valueOf(request.getParameter("id")); String username = request.getParameter("username"); String password = request.getParameter("password"); int sex = Integer.valueOf(request.getParameter("sex")); String address = request.getParameter("address"); try { //先加载lib目录下的java-connect-mysql.jar驱动包 Class.forName("com.mysql.jdbc.Driver"); //选择驱动类，连接地址、账号密码，连接MySQL String driverClass="com.mysql.jdbc.Driver"; String url="jdbc:mysql://localhost:3306/school?useUnicode=true&characterEncoding=utf-8"; String sqlusername="root"; String sqlpassword="root"; Connection conn = DriverManager.getConnection(url, sqlusername, sqlpassword); //编写SQL语句，这里不要用statement了，换用preparedstatement，因为 //preparedstatement可以设置？为形参，然后set各个形参的实际值，statement没有此 //功能。最后执行更新语句。 //此外，？不要加单双引号，否则报错java.sql.SQLException: Parameter index out of range (0 < 1 ). String sql = "update student set username = ?, password = ?, sex = ?, address = ? where id = ?"; PreparedStatement ps = conn.prepareStatement(sql); ps.setString(1, username); ps.setString(2, password); ps.setInt(3, sex); ps.setString(4, address); ps.setInt(5, id); ps.executeUpdate(); //关闭连接 ps.close(); conn.close(); } catch (SQLException | ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } //跳转到显示页面 response.sendRedirect("findAllServlet"); /*request.getRequestDispatcher("listStudent.jsp") .forward(request, response); */ } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } }
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