连接数据库
db.properties
url=jdbc\:MysqL\://localhost\:3306/csdn?useUnicode\=true&characterEncoding\=UTF-8
user=root
pass=113
driverClassName=com.MysqL.jdbc.Driver
工具包DBConn.java
package util;
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.util.Properties;
public class DBConn {
private static Connection conn;
private DBConn() {
}
public static Connection getConn() {
if (conn == null) {
// 创建集合对象
Properties properties = new Properties();
try {
// 装载
properties.load(DBConn.class.getClassLoader()
.getResourceAsStream("db.properties"));
// 加载驱动程序
Class.forName(properties.getProperty("driverClassName"));
// 获取连接对象
conn = DriverManager.getConnection(
properties.getProperty("url"),properties.getProperty("user"),properties.getProperty("pass"));
conn.setAutoCommit(false);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
return conn;
}
/**
* 单个数据的增加更新删除的事务处理
* @param sql
* @param params
* @param pstmt
*/
public static void update(String sql,Object params[],PreparedStatement pstmt) {
try {
pstmt = getConn().prepareStatement(sql);
for (int i = 0; i < params.length; i++) {
pstmt.setObject(i + 1,params[i]);
}
pstmt.executeUpdate();
conn.commit();
} catch (Exception e) {
try {
conn.rollback();
} catch (sqlException e1) {
e1.printStackTrace();
}
e.printStackTrace();
} finally {
release(null,pstmt);
}
}
public static void release(ResultSet rs,PreparedStatement pstmt) {
if (rs != null) {
try {
rs.close();
} catch (sqlException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if (pstmt != null) {
try {
pstmt.close();
} catch (sqlException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
读取数据库的信息
UserDomian.java
package www.csdn.net.user.domian;
public class UserDomian {
private Integer id;
private String name;
private String pass;
public UserDomian() {
// TODO Auto-generated constructor stub
}
public UserDomian(Integer id,String name,String pass) {
super();
this.id = id;
this.name = name;
this.pass = pass;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getPass() {
return pass;
}
public void setPass(String pass) {
this.pass = pass;
}
@Override
public String toString() {
return "UserDomian [id=" + id + ",name=" + name + ",pass=" + pass + "]";
}
}
实现增删查改功能
UserDo.java
package www.csdn.net.user.dao;
import java.util.List;
import www.csdn.net.user.domian.UserDomian;
public interface UserDo {
void insert(UserDomian entity) throws Exception;
void update(UserDomian entity) throws Exception;
void delete(UserDomian entity) throws Exception;
void deleteById(Integer id) throws Exception;
List<UserDomian> findAll() throws Exception;
UserDomian findById(Integer id) throws Exception;
/**
* 用户登录验证
*/
UserDomian checkLogin(String name,String pass) throws Exception;
/**
* 批量删除操作
*/
void deletes(Integer ids[]) throws Exception;
/**
* 分页处理
*/
List<UserDomian> findNowPageInfo(int nowpage) throws Exception;
/**
* 总页
*/
Integer getCountPage() throws Exception;
/**
* 判断用户信息是否存在
*/
boolean checkName(String name) throws Exception;
}
实现接口的类UserDoImpl.java
package www.csdn.net.user.dao.impl;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
import util.DBConn;
import www.csdn.net.user.dao.UserDo;
import www.csdn.net.user.domian.UserDomian;
public class UserDoImpl implements UserDo {
private Connection conn;
private PreparedStatement pstmt;
private ResultSet rs;
final int PAGESIZE = 10;
@Override
public void insert(UserDomian entity) throws Exception {
String sql = "insert into user (name,pass) values(?,?)";
DBConn.update(sql,new Object[] { entity.getName(),entity.getPass() },pstmt);
}
@Override
public void update(UserDomian entity) throws Exception {
String sql = "update user set name=?,pass=? where id=?";
DBConn.update(sql,entity.getPass(),entity.getId() },pstmt);
}
@Override
public void delete(UserDomian entity) throws Exception {
String sql = "delete from user where id=?";
DBConn.update(sql,new Object[] { entity.getId() },pstmt);
}
@Override
public void deleteById(Integer id) throws Exception {
String sql = "delete from user where id=?";
DBConn.update(sql,new Object[] { id },pstmt);
}
@Override
public List<UserDomian> findAll() throws Exception {
List<UserDomian> entities = new ArrayList<UserDomian>();
String sql = "select id,name,pass from user ";
conn = DBConn.getConn();
pstmt = conn.prepareStatement(sql);
rs = pstmt.executeQuery();
while (rs.next()) {
UserDomian entity = new UserDomian();
entity.setId(rs.getInt("id"));
entity.setName(rs.getString("name"));
entity.setPass(rs.getString("pass"));
entities.add(entity);
}
return entities;
}
@Override
public UserDomian findById(Integer id) throws Exception {
UserDomian entity = null;
String sql = "select id,pass from user where id=?";
conn = DBConn.getConn();
pstmt = conn.prepareStatement(sql);
int index = 1;
pstmt.setInt(index++,id);
rs = pstmt.executeQuery();
if (rs.next()) {
entity = new UserDomian();
entity.setId(rs.getInt("id"));
entity.setName(rs.getString("name"));
entity.setPass(rs.getString("pass"));
}
return entity;
}
@Override
public UserDomian checkLogin(String name,String pass) throws Exception {
UserDomian entity = null;
String sql = "select id,pass from user where name=? and pass=?";
conn = DBConn.getConn();
pstmt = conn.prepareStatement(sql);
int index = 1;
pstmt.setString(index++,name);
pstmt.setString(index++,pass);
rs = pstmt.executeQuery();
if (rs.next()) {
entity = new UserDomian();
entity.setId(rs.getInt("id"));
entity.setName(rs.getString("name"));
entity.setPass(rs.getString("pass"));
}
return entity;
}
@Override
public void deletes(Integer[] ids) throws Exception {
conn = DBConn.getConn();
try {
for (int i = 0; i < ids.length; i++) {
String sql = "delete from user where id=?";
pstmt = conn.prepareStatement(sql);
pstmt.setInt(1,ids[i]);
pstmt.executeUpdate();
// pstmt.addBatch();
}
// pstmt.executeBatch();
conn.commit();
} catch (Exception e) {
conn.rollback();
e.printStackTrace();
}
}
@Override
public List<UserDomian> findNowPageInfo(int nowpage) throws Exception {
List<UserDomian> entities = new ArrayList<UserDomian>();
String sql = "select id,pass from user limit ?,?";
conn = DBConn.getConn();
pstmt = conn.prepareStatement(sql);
int index = 1;
pstmt.setInt(index++,(nowpage - 1) * PAGESIZE);
pstmt.setInt(index++,PAGESIZE);
rs = pstmt.executeQuery();
while (rs.next()) {
UserDomian entity = new UserDomian();
entity.setId(rs.getInt("id"));
entity.setName(rs.getString("name"));
entity.setPass(rs.getString("pass"));
entities.add(entity);
}
return entities;
}
// 总页数
@Override
public Integer getCountPage() throws Exception {
String sql = "select count(*) as c from user";
conn = DBConn.getConn();
pstmt = conn.prepareStatement(sql);
rs = pstmt.executeQuery();
while (rs.next()) {
int countsize = rs.getInt("c");
return countsize % PAGESIZE == 0 ? countsize / PAGESIZE : countsize
/ PAGESIZE + 1;
}
return null;
}
@Override
public boolean checkName(String name) throws Exception {
boolean flag = false;
String sql = "select id,pass from user where name=?";
conn = DBConn.getConn();
pstmt = conn.prepareStatement(sql);
int index = 1;
pstmt.setString(index++,name);
rs = pstmt.executeQuery();
if (rs.next()) {
flag = true;
}
return flag;
}
}
验证码RandomImage .java
package img;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.Random;
/**
* 验证码
* @author yanmei
*
*/
public class RandomImage {
private final static int W=80;
private final static int H=30;
public static BufferedImage createImage(){
//创建图片
BufferedImage image=new BufferedImage(W,H,BufferedImage.TYPE_INT_RGB);
//得到图形绘制的对象
Graphics g=image.getGraphics();
//设置背景颜色
setBackGroud(g);
//设置边框
setBorder(g);
//绘制内容
drawContent(g);
//绘制干扰线
drawDisturbline(g);
return image;
}
private static void drawDisturbline(Graphics g) {
g.setColor(Color.blue);
Random r=new Random();
for (int i = 0; i < 4; i++) {
int x1 = r.nextInt(W);
int y1 = r.nextInt(H);
int x2 = r.nextInt(W);
int y2 = r.nextInt(H);
g.drawLine(x1,y1,x2,y2);
}
}
private static void drawContent(Graphics g) {
// TODO Auto-generated method stub
//字节资源
String re = "u7684\u4e00\u4e86\u662f\u6211\u4e0d\u5728\u4eba\u4eec\u6709\u6765\u4ed6\u8fd9\u4e0a\u7740\u4e2a\u5730\u5230\u5927\u91cc\u8bf4\u5c31\u53bb\u5b50\u5f97\u4e5f\u548c\u90a3\u8981\u4e0b\u770b\u5929\u65f6\u8fc7\u51fa\u5c0f\u4e48\u8d77\u4f60\u90fd\u628a\u597d\u8fd8\u591a\u6ca1\u4e3a\u53c8\u53ef\u5bb6\u5b66\u53ea\u4ee5\u4e3b\u4f1a\u6837\u5e74\u60f3\u751f\u540c\u8001\u4e2d\u5341\u4ece\u81ea\u9762\u524d\u5934\u9053\u5b83\u540e\u7136\u8d70\u5f88\u50cf\u89c1\u4e24\u7528\u5979\u56fd\u52a8\u8fdb\u6210\u56de\u4ec0\u8fb9\u4f5c\u5bf9\u5f00\u800c\u5df1\u4e9b\u73b0\u5c71\u6c11\u5019\u7ecf\u53d1\u5de5\u5411\u4e8b\u547d\u7ed9\u957f\u6c34\u51e0\u4e49\u4e09\u58f0\u4e8e\u9ad8\u624b\u77e5\u7406\u773c\u5fd7\u70b9\u5fc3\u6218\u4e8c\u95ee\u4f46\u8eab\u65b9\u5b9e\u5403\u505a\u53eb\u5f53\u4f4f\u542c\u9769\u6253\u5462\u771f\u5168\u624d\u56db\u5df2\u6240\u654c\u4e4b\u6700\u5149\u4ea7\u60c5\u8def\u5206\u603b\u6761\u767d\u8bdd\u4e1c\u5e2d\u6b21\u4eb2\u5982\u88ab\u82b1\u53e3\u653e\u513f\u5e38\u6c14\u4e94\u7b2c\u4f7f\u5199\u519b\u5427\u6587\u8fd0\u518d\u679c\u600e\u5b9a\u8bb8\u5feb\u660e\u884c\u56e0\u522b\u98de\u5916\u6811\u7269\u6d3b\u90e8\u95e8\u65e0\u5f80\u8239\u671b\u65b0\u5e26\u961f\u5148\u529b\u5b8c\u5374\u7ad9\u4ee3\u5458\u673a\u66f4\u4e5d\u60a8\u6bcf\u98ce\u7ea7\u8ddf\u7b11\u554a\u5b69\u4e07\u5c11\u76f4\u610f\u591c\u6bd4\u9636\u8fde\u8f66\u91cd\u4fbf\u6597\u9a6c\u54ea\u5316\u592a\u6307\u53d8\u793e\u4f3c\u58eb\u8005\u5e72\u77f3\u6ee1\u65e5\u51b3\u767e\u539f\u62ff\u7fa4\u7a76\u5404\u516d\u672c\u601d\u89e3\u7acb\u6cb3\u6751\u516b\u96be\u65e9\u8bba\u5417\u6839\u5171\u8ba9\u76f8\u7814\u4eca\u5176\u4e66\u5750\u63a5\u5e94\u5173\u4fe1\u89c9\u6b65\u53cd\u5904\u8bb0\u5c06\u5343\u627e\u4e89\u9886\u6216\u5e08\u7ed3\u5757\u8dd1\u8c01\u8349\u8d8a\u5b57\u52a0\u811a\u7d27\u7231\u7b49\u4e60\u9635\u6015\u6708\u9752\u534a\u706b\u6cd5\u9898\u5efa\u8d76\u4f4d\u5531\u6d77\u4e03\u5973\u4efb\u4ef6\u611f\u51c6\u5f20\u56e2\u5c4b\u79bb\u8272\u8138\u7247\u79d1\u5012\u775b\u5229\u4e16\u521a\u4e14\u7531\u9001\u5207\u661f\u5bfc\u665a\u8868\u591f\u6574\u8ba4\u54cd\u96ea\u6d41\u672a\u573a\u8be5\u5e76\u5e95\u6df1\u523b\u5e73\u4f1f\u5fd9\u63d0\u786e\u8fd1\u4eae\u8f7b\u8bb2\u519c\u53e4\u9ed1\u544a\u754c\u62c9\u540d\u5440\u571f\u6e05\u9633\u7167\u529e\u53f2\u6539\u5386\u8f6c\u753b\u9020\u5634\u6b64\u6cbb\u5317\u5fc5\u670d\u96e8\u7a7f\u5185\u8bc6\u9a8c\u4f20\u4e1a\u83dc\u722c\u7761\u5174\u5f62\u91cf\u54b1\u89c2\u82e6\u4f53\u4f17\u901a\u51b2\u5408\u7834\u53cb\u5ea6\u672f\u996d\u516c\u65c1\u623f\u6781\u5357\u67aa\u8bfb\u6c99\u5c81\u7ebf\u91ce\u575a\u7a7a\u6536\u7b97\u81f3\u653f\u57ce\u52b3\u843d\u94b1\u7279\u56f4\u5f1f\u80dc\u6559\u70ed\u5c55\u5305\u6b4c\u7c7b\u6e10\u5f3a\u6570\u4e61\u547c\u6027\u97f3\u7b54\u54e5\u9645\u65e7\u795e\u5ea7\u7ae0\u5e2e\u5566\u53d7\u7cfb\u4ee4\u8df3\u975e\u4f55\u725b\u53d6\u5165\u5cb8\u6562\u6389\u5ffd\u79cd\u88c5\u9876\u6025\u6797\u505c\u606f\u53e5\u533a\u8863\u822c\u62a5\u53f6\u538b\u6162\u53d4\u80cc\u7ec6";
//获取字符的长度
int length=re.length();
//随机操作对象
Random r=new Random();
//存储字符的对象
StringBuffer sb=new StringBuffer();
for (int i = 0; i < 4; i++) {
//随机产生数字
int index=r.nextInt(length);
//获取字符
char c=re.charAt(index);
sb.append(c);
}
g.setColor(Color.black);
g.drawString(sb.toString(),20,20);
}
private static void setBorder(Graphics g) {
g.setColor(Color.black);
g.drawRect(0,W-2,H-2);
}
private static void setBackGroud(Graphics g) {
// 绘制矩形
g.setColor(Color.yellow);
g.fillRect(0,W,H);
}
}
package www.csdn.net.ajax.servlet;
import java.awt.Color;
import java.awt.Graphics;
import java.io.IOException;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import img.RandomImage;
public class ImageServlet extends HttpServlet {
public void doGet(HttpServletRequest request,HttpServletResponse response)
throws ServletException,IOException {
//禁止浏览器缓存数据
response.setHeader("expires","0");
response.setHeader("Cache-Control","no-cache");
response.setHeader("Pragma","no-cache");
//1.通知浏览器以图片的方式打开数据
response.setContentType("image/jpeg");
//把图片显示给浏览器
ImageIO.write(RandomImage.createImage(),"jpeg",response.getOutputStream());
}
public void doPost(HttpServletRequest request,IOException {
this.doGet(request,response);
}
}
login.jsp
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
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 'login.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">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
<!-- 引入js文件 -->
<script type="text/javascript" >
//当窗体加载完毕后触发该函数
window.onload = function(){
//获取name输入框的Dom对象
var inputName = document.getElementById("uname");
//注册事件
inputName.onblur= checkName;
};
function checkName(){
var name = this.value;
//1.第一步获取XMLHttpRequest对象
var xmlHttp = getXMLHttp();
//2. 第二步：打开请求
xmlHttp.open("GET","./checkName.do?name="+name+"&oper=checkName");
//3.第三步：发送请求
xmlHttp.send(null);//checkName.do
//4.第四步：函数处理
xmlHttp.onreadystatechange= processProgram;
}
function processProgram(){
//判断是否处理完成，响应的是否正常
//alert("11111111111111111111");
if(this.readyState==4&&this.status==200){
//服务器端响应过来的文本
var content = this.responseText;
//alert("---"+content);
//获取显示文本的span,Dom节点对象
var msgDom = document.getElementById("msg");
//清除操作
var childNodes = msgDom.childNodes;
for(var i=0;i<childNodes.length;i++){
//删除所有的孩子节点
msgDom.removeChild(childNodes[i]);
}
//创建一个文本节点对象
var textDom =document.createTextNode(content);
//在显示文本的span，Dom节点中添加textDom的孩子节点
msgDom.appendChild(textDom);
}
}
function getXMLHttp() {
// 第一步：声明返回值
var xmlHttp;
// 第二步：实例化xmlHttp对象
try {
// firefox Opera等
xmlHttp = new XMLHttpRequest();
} catch (e) {
try {
// IE浏览器
xmlHttp = new ActiveXObject("MSXML2.XMLHTTP5.0");
} catch (ex) {
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
}
return xmlHttp;
}
</script>
</head>
<body>
<div align="center">
<form action="./login.action" method="post">
<table border="1px" cellpadding="0" cellspacing="0">
<tr>
<td>用户名:</td>
<td><input type="text" name="name" id="uname"/></td>
<td><span id="msg"></span></td>
</tr>
<tr>
<td>密码:</td>
<td colspan="2"><input type="password" name="pass" /></td>
</tr>
<tr>
<td>验证码:</td>
<td><input type="text" name="code" /></td>
<td><img alt="验证码" src="./servlet/ImageServlet"></td>
</tr>
<tr>
<td colspan="3" align="center"><input type="reset" value="重置" />
<input type="submit" value="登录" /></td>
</tr>
</table>
</form>
</div>
</body>
</html>
web.xml<?xml version="1.0" encoding="UTF-8"?>
<web-app version="3.0"
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_3_0.xsd">
<display-name></display-name>
<servlet>
<servlet-name>AjaxServlet</servlet-name>
<servlet-class>www.csdn.net.ajax.servlet.AjaxServlet</servlet-class>
</servlet>
<servlet>
<servlet-name>ImageServlet</servlet-name>
<servlet-class>www.csdn.net.ajax.servlet.ImageServlet</servlet-class>
</servlet>
<servlet>
<servlet-name>AdminServlet</servlet-name>
<servlet-class>www.csdn.net.ajax.servlet.AdminServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>AjaxServlet</servlet-name>
<url-pattern>/ajaxServlet.do</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>AdminServlet</servlet-name>
<url-pattern>/checkName.do</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>ImageServlet</servlet-name>
<url-pattern>/servlet/ImageServlet</url-pattern>
</servlet-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
</web-app>
package www.csdn.net.ajax.servlet;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import www.csdn.net.user.dao.UserDo;
import www.csdn.net.user.dao.impl.UserDoImpl;
public class AdminServlet extends HttpServlet {
private UserDo userDo=new UserDoImpl();
public void doGet(HttpServletRequest request,IOException {
String oper = request.getParameter("oper");
if ("checkName".equals(oper))
// 验证用户操作
checkName(request,response);
// System.out.println(oper);
}
public void checkName(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException {
String name = request.getParameter("name");
boolean flag=false;
try {
flag=userDo.checkName(name);
} catch (Exception e) {
e.printStackTrace();
}
//设置响应
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
PrintWriter out=response.getWriter();
if (flag) {
out.write("用户名被占用");
}else{
out.write("用户名可用");
}
//System.out.println("----------------------");
out.flush();
out.close();
}
public void doPost(HttpServletRequest request,IOException {
this.doGet(request,response);
}
}
