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2019-11-08 01:04:46

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JDBC连接数据库学习jsp，通过jdbc技术连接数据库进行对数据的查询。准备: MySQL, myeclipse. 1. 首先在myeclipse中新建一个web项目这里写图片描述 2. 在src文件夹中新建一个实现数据库查询的java类 3. 在写查询代码前首先先写一个关于要查讯字段的类用来保存从数据库表中查询到的数据，此处以学生类为例

package cn.edu.bzu.entry;public class Student { PRivate String name; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public String getPhone() { return phone; } public void setPhone(String phone) { this.phone = phone; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } public String getQQ() { return qq; } public void setQq(String qq) { this.qq = qq; } public String getSchool() { return school; } public void setSchool(String school) { this.school = school; } private String sex; private String phone; private String address; private String qq; private String school;}

下面即实现查询数据库中内容的java类：

package cn.edu.bzu;import java.sql.Connection;import java.sql.DriverManager;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.util.ArrayList;import java.util.List;import cn.edu.bzu.entry.Student;public class StudentDao { public List getAllStudent(){ List allStudents = new ArrayList();//保存所有学生 Connection conn = null; PreparedStatement pstmt = null; ResultSet rs = null; try { Class.forName("com.mysql.jdbc.Driver"); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/firstdb", "root", "123456"); pstmt = conn.prepareStatement("select * from stu"); rs = pstmt.executeQuery(); while (rs.next()) { Student s = new Student(); s.setName(rs.getString("name")); s.setAddress(rs.getString("address")); s.setPhone(rs.getString("phone")); s.setSex(rs.getString("sex")); s.setSchool(rs.getString("school")); s.setQq(rs.getString("qq")); allStudents.add(s); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally{ if(rs!=null){ try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } } if(pstmt!=null){ try { pstmt.close(); } catch (SQLException e) { e.printStackTrace(); } } if(conn!=null){ try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } } } return allStudents; }}

到这时，对业务的处理也就完成了，剩下的就是页面的显示了。此处用jsp页面显示。下面即jsp代码：

<%@page import="cn.edu.entry.Student"%><%@page import="cn.edu.bzu.StudentDao"%><%@ page language="java" import="java.util.*" pageEncoding="gbk"%><% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <base href="<%=basePath%>"> <title>My JSP 'index.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keyWords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="This is my page">  </head> <body> <center><h3>学生表</h3><table border="1"><tr><td>姓名</td><td>性别</td><td>电话</td><td>qq号</td><td>学校</td><td>地址</td></tr><%StudentDao sd = new StudentDao();List allStudent = sd.getStudent();for(int i=0;i<allStudent.size();i++){Student s=(Student)allStudent.get(i);%><tr><td><%=s.getName() %></td><td><%=s.getSex() %></td><td><%=s.getPhone() %></td><td><%=s.getQq() %></td><td><%=s.getSchool() %></td><td><%=s.getAddress() %></td></tr><%} %></table></center> </body></html>

总结如上！

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