html调用servlet（JDBC在Servlet中的使用）（1）
1.页面的数据表单
在使用Servlet处理用户请求之前，先准备一个页面，该页面用来提供数据表单。数据表单就是HTML中的<form>...</form>部分，当用户单击Submit按钮提交表单之后，表单中包含的一些变量（或者成为字段）将会被发送到服务器端进行处理。下面编写一个HTML文件，文件代码如下：
add.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>add.html</title> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=GB2312"> <!--<link rel="stylesheet" type="text/css" href="./styles.css">--> </head> <body>
<form action="/jdbc_servlet/servlet/addServlet" method="post">
<label>请输入部门信息：</label><br><br>
<label>部门号：</label><br>
<input type="text" name="id"/><br>
<label>部门名：</label><br>
<input type="text" name="name"/><br>
<label>部门人数：</label><br>
<input type="text" name="num"/><br>
<label>地址：</label><br>
<input type="text" name="address"/><br><br>
<input type="submit" value="提交"/><br>
</form>
</body>
</html>
2.添加数据
Servlet的好处之一就是可以简单地获得表单中的数据。在Servlet中使用JDBC技术实现添加的代码如下：
addServlet.java
package com.cn.add; import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
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 addServlet extends HttpServlet { /**
* Constructor of the object.
*/
public addServlet() {
super();
} /**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
} /**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { response.setContentType("text/html;charset=gb2312");
PrintWriter out = response.getWriter();
this.doPost(request, response);
out.flush();
out.close();
} /**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
System.out.println("到了Servlet！！！");
response.setContentType("text/html;charset=gb2312");
request.setCharacterEncoding("gb2312");
PrintWriter out = response.getWriter();
String id = request.getParameter("id"); //获取部门编号
String name = request.getParameter("name"); //获取部门名称
String address = request.getParameter("address"); //获取部门所在地址
int num = Integer.parseInt(request.getParameter("num")); //获取部门人数
Connection conn = null; //声明一个Connection对象，用来连接数据库
PreparedStatement pstmt = null; //声明PreparedStatement对象，用来向数据库插入数据条数据
try {
//连接到MySQL数据库中的bank数据库模式
Class.forName("com.mysql.jdbc.Driver");
System.out.println("创建驱动成功！");
//连接数据库
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/bank", "root", "1234");
System.out.println("连接数据库成功！");
//插入数据的SQL语句
String sql = "INSERT INTO dept(id,d_name,address,empnumber) VALUES(?,?,?,?)";
pstmt = conn.prepareStatement(sql);
//设置插入数据的顺序
pstmt.setString(1, id);
pstmt.setString(2, name);
pstmt.setString(3, address);
pstmt.setInt(4, num);
int result = pstmt.executeUpdate();
//判断执行结果
if (result == 1) {
out.print("插入数据成功！");
}else {
out.print("插入数据失败！请重新插入！");
}
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
out.flush();
out.close();
} /**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
} }
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">
<servlet>
<description>This is the description of my J2EE component</description>
<display-name>This is the display name of my J2EE component</display-name>
<servlet-name>addServlet</servlet-name>
<servlet-class>com.cn.add.addServlet</servlet-class>
</servlet> <servlet-mapping>
<servlet-name>addServlet</servlet-name>
<url-pattern>/servlet/addServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
文件整体框架如下：
3.查看单条数据
一般一条数据的id是唯一的，查看单条记录的时候，可以根据id来查询。HTML页面的代码如下：
showById.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>showById.html</title> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="this is my page">
<meta http-equiv="content-type" content="text/html; charset=gb2312"> <!--<link rel="stylesheet" type="text/css" href="./styles.css">--> </head> <body>
<form name="f1" id="f1" action="/jdbc_servlet/servlet/SearchEmployee" method="post">
<table border="0">
<tr>
<td>请输入部门编号：</td><tr/><tr/>
<td><input type="text" name="id"></td>
</tr>
<tr>
<td colspan="2" align="left"><input type="submit" value="查找"></td>
</tr>
</table>
</form>
</body>
</html>
在该页面中输如id号，点击查找按钮时会进入查询的Servlet，在Servlet中处理根据id查询的操作。根据id查询的Servlet代码如下：
SearchEmployee.java
package com.cn.query; import java.io.IOException;
import java.io.PrintWriter;
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 SearchEmployee extends HttpServlet { /**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
} /**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { response.setContentType("text/html;charset=gb2312");
request.setCharacterEncoding("gb2312");
PrintWriter out = response.getWriter();
String id = request.getParameter("id"); //获取部门编号
Connection conn = null; //声明一个Connection对象，用来连接数据库
PreparedStatement pstmt = null;
ResultSet rs = null;
try {
Class.forName("com.mysql.jdbc.Driver");
System.out.println("创建驱动成功！");
//连接数据库
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/bank", "root", "1234");
System.out.println("连接数据库成功！");
String sql = "SELECT * FROM dept WHERE id = ?";
pstmt = conn.prepareStatement(sql);
pstmt.setString(1, id);
rs = pstmt.executeQuery();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
while(rs.next()){
out.print("部门编号："+rs.getString(1)+"\n");
out.print("部门名称："+rs.getString(2)+"\n");
out.print("部门地址："+rs.getString(3)+"\n");
out.print("部门人数："+rs.getString(4)+"\n");
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
out.flush();
out.close();
} /**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { response.setContentType("text/html;charset=gb2312");
request.setCharacterEncoding("gb2312");
PrintWriter out = response.getWriter();
this.doGet(request, response);
out.flush();
out.close();
} /**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occurs
*/
public void init() throws ServletException {
// Put your code here
} }
目录结构如下：
4.显示一张表中的全部数据
显示表中全部数据信息的Servlet代码如下：
DeptList.java
package com.cn.query; import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse; public class DeptList extends HttpServlet { /**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException { response.setContentType("text/html;charset=gb2312");
request.setCharacterEncoding("gb2312");
PrintWriter out = response.getWriter();
Connection conn = null;
Statement stmt = null;
ResultSet rs = null;
try {
Class.forName("com.mysql.jdbc.Driver");
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/bank", "root", "1234");
stmt = conn.createStatement();
rs = stmt.executeQuery("SELECT * FROM dept");
//在页面中显示表中的所有信息
out.println(
"<html>"+
"<head><title>部门表信息</title></head>"+
"<body>");
out.println("<h1>部门表信息:</h1><br><br>");
//循环遍历输出查询结果
while(rs.next()){
out.print("部门编号：");
out.print(rs.getString(1)+"\t");
out.print("部门名称：");
out.print(rs.getString(2)+"\t");
out.print("部门地址：");
out.print(rs.getString(3)+"\t");
out.print("部门人数：");
out.print(rs.getString(4)+"\t");
out.print("<br>");
}
out.print("</body></html>");
out.close();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} public void init() throws ServletException {
// Put your code here
} }
html调用servlet（JDBC在Servlet中的使用）（1）的更多相关文章
- Java Servlet(三)：Servlet中ServletConfig对象和ServletContext对象
本文将记录ServletConfig/ServletContext中提供了哪些方法,及方法的用法. ServletConfig是一个抽象接口,它是由Servlet容器使用,在一个servlet对象初始 ...
- 登录小项目 js+servlet+jdbc+mvc
项目名称: 沪上阿姨 实现需求: 实现用户登录 实现用户退出 实现用户注册 功能分析: 用户登录: 根据用户名和密码查询用户信息.查询则登录成功,查不到则登录失败. 用户退出: 销毁session 用 ...
- JDBC和servlet设计思路、DAO模式思路、MVC思路粗略总结
#JDBC和Servlet联合起来使用的项目思路: 说明:建库,最好一开始设置utf8字符集 step1: 在数据库中建表 如 create table t_user{ ...... } step ...
- Jsp+Servlet+JDBC的使用复习
最近对JDBC进行了复习,对事物的理解,连接池的使用等部分都有一个复习,所以使用Servlet+JDBC完成了一个小Demo,在这里对这种底层的操作进行总结.框架的使用的确方便了我们的开发,但是底层的 ...
- java web开发基础实例（javabean+jsp+servlet+jdbc）
JavaBean:用于传递数据,拥有与数据相关的逻辑处理 JSP:从Model接收数据并生成HTML Servlet:接收HTTP请求并控制Model和View jdbc:用于配置环境 一.[建立数据 ...
- 使用JSP+Servlet+Jdbc+Echatrs实现对豆瓣电影Top250的展示
使用JSP+Servlet+Jdbc+Echatrs实现对豆瓣电影Top250的展示 写在前面: 有的小伙伴,会吐槽啦,你这个标题有点长的啊.哈哈 ,好像是的!不过,这个也是本次案例中使用到的关键技术 ...
- 使用servlet+jdbc+MD5实现用户加密登录
/** * 分析流程: * 1.前端页面提交登录请求 * 2.被web.xml拦截,进入到LoginServlet(有两种方式:方式一,在web.xml文件中配置servlet拦截器;方式二,不用在w ...
- Servlet从本地文件中读取图片，并显示在页面中
import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpSer ...
- MVC-1(javabean+jsp+servlet+jdbc)
这是一篇最初版本的mvc设计模式的demo.路要一步一步走,弄明白这其中的逻辑,对后面掌握ssh,ssm等框架大有裨益. 计算机系的同学们也要为毕设做准备了,希望可以帮你们迈出自己做毕设的第一步(微笑 ...
随机推荐
- shell心得
向loader.ctl中插入文本
- Session机制二（简易购物车案例）
一:案例一(简易购物车) 1.目录结构 2.step1.jsp <%@ page language="java" contentType="text/html; c ...
- ionic路由(页面切换)
ui-router 的工作原理非常类似于 Angular 的路由控制器,但它只关注状态. • 在应用程序的整个用户界面和导航中,一个状态对应于一个页面位置 • 通过定义controller.templ ...
- IAR搭建unity框架
1. 新建工程 2. 增加组 unit,并加入相应源码 3. 增加需要测试的API源文件 4. 编写相应的测试用例 编译,download and debug view->TerminalIO ...
- POJ - 1329 Circle Through Three Points 求圆
Circle Through Three Points Time Limit: 1000MS Memory Limit: 10000K Total Submissions: 4112 Acce ...
- gpfs中遇到的错误
主要导致这个问题是之前GPFS格式化的磁盘会留下gpfs的一些信息 mmcrnsd: Disk name nsd01 is already registered for use by GPFS.mmc ...
- android OOM 内存溢出
韩梦飞沙 韩亚飞 313134555@qq.com yue31313 han_meng_fei_sha 一个应用的可用内存是有限的,如果超过了可用的内存,就会内存溢出. 1,避免 已经不用的对 ...
- 汇编代码中db，dw，dd的区别
db定义字节类型变量,一个字节数据占1个字节单元,读完一个,偏移量加1 dw定义字类型变量,一个字数据占2个字节单元,读完一个,偏移量加2 dd定义双字类型变量,一个双字数据占4个字节单元,读完一个, ...
- [UVa10296]Jogging Trails
题目大意: 中国邮递员问题. 给你一个无向带权连通图,求经过所有边并返回起点的最短路径. 思路: Edmonds-Johnson算法. 显然,当原图为欧拉图时,答案即为其欧拉回路的长度. 考虑原图不存 ...
- Codeforces Round #257 (Div. 2) C. Jzzhu and Chocolate
C. Jzzhu and Chocolate time limit per test 1 second memory limit per test 256 megabytes input standa ...