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【JSP基础】JSP实现登录注册界面

2015-07-29 11:36 861 查看
初学者,很多迷惑,把自己写的东西记录下来,希望帮到各位以外,也希望自己有迷惑的时候再回来看一看,解除迷惑。

首先是JAVAbeen:



public class User {

protected int username;
protected String password;
protected String code;
public int getUsername() {
return username;
}
public void setUsername(int username) {
this.username = username;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getCode() {
return code;
}
public void setCode(String tell) {
this.code = code;
}

之后,我们需要建立一个与之对应的数据库表,这里用的是mysql数据库,


所以我们要在WEB-INT/lib路径下导入与数据库连接的jre包,这里用的是:

做好准备工作之后,就开始我们的工程了。

写一个与数据库连接的class。
public class DBOperator {

protected final static  String driver = "com.mysql.jdbc.Driver";
protected final static  String url = "jdbc:mysql://localhost:3306/当前所要使用的数据库名";

static {
try {

Class.forName(driver);

} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}

public static Connection getconnection( ){
Connection conn = null;
try {

conn= (Connection) DriverManager.getConnection(url,"root","root");//只是mysql进入的用户名和密码。

} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}

return conn;

}

public static void close (Statement st, ResultSet rs, Connection conn ){

try {

if(st!=null){
st.close();
}

if (rs!=null){
rs.close();
}
if(conn!=null){
conn.close();
}
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}

}

public static void close(PreparedStatement pst, Connection conn){

try {

if(pst!=null){
pst.close();
}
if(conn!=null){
conn.close();
}

} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}

}
}


接着,需要建立我们完成登录所用的两个方法,首先写一个接口,这样会让代码更规范,执行效率更高。

public interface UserManager {

public boolean add( User u);
public boolean addm( int username ,String password);

}


然后就是实现这个接口的类:(登录和注册需要的两个方法)

public class UserManagerImpl  implements UserManager{

@Override
public boolean add(User u) {
// TODO Auto-generated method stub
boolean flag = false;
Connection conn = null;
PreparedStatement pst = null;

try {

conn = DBOperator.getconnection();
String sql = "insert into t_users (username,password,code) value(?,?,?)";
pst = (PreparedStatement) conn.prepareStatement(sql);
pst.setInt(1, u.getUsername());
pst.setString(2, u.getPassword());
pst.setString(3, u.getCode());

int rows = pst.executeUpdate();
if(rows>0){
flag= true;
}

} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}finally{
DBOperator.close(pst, conn);
}

return flag;
}

@Override
public boolean addm(int username, String password) {
// TODO Auto-generated method stub
boolean flag = false;
Connection conn = null;
Statement st = null;
ResultSet rs = null;

try {

conn = DBOperator.getconnection();
String sql = "select * from t_users where username="+username;
st = (Statement) conn.createStatement();
rs = (ResultSet) st.executeQuery(sql);

while(rs.next()){
if (rs.getString("password").equals(password)){
flag = true;
}
}

} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}finally{
DBOperator.close(st, rs, conn);
}

return flag;
}

}


完成之后开始写登录的jsp网页:登录这里用到了关于验证码的东西,验证码先不解释,最后解释。

<%@ 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 '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">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->

<script type="text/javascript">
function reLoadCode(){
var t = new Date().getTime();
document.getElementById("imagecode").src ="ImageServlet?t="+t;
}
</script>
</head>

<body>
<form action="addm" method="post" align="center">
<cneter><h1>登录</h1></cneter>
<b>用户名:</b><input type="text" name="Username" style="width: 193px; "><br>
<p></p>
<b>密    码:</b><input type="password" name="Password" style="width: 193px; "><br>
<p></p>
验证码:<input name="Checkcode" type="text"  style="width: 193px; ">
<img alt="验证码" src="ImageServlet" id="imagecode">
<a href="javaScript:reLoadCode()">看不清</a>
<br>
<font  size="+1"  >
<p>      
<input name="submit"  type="submit" class="button"  style="width:200px; height:35px " value="登录" />
</p>
<p>                               
                   
          <font  size="-1"  color="#000099"><a href="zhuce.jsp">注册</a> </font> </p>
</font>

</form>
</body>
</html>

建立jsp后,需要建立一个servlet去接收form表单传来的数据。

public class addm extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}

/**
* 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 {

request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");

int un = Integer.parseInt(request.getParameter("Username"));
String pswd = request.getParameter("Password");
String checkcode = request.getParameter("Checkcode");

String pickcode = (String) request.getSession().getAttribute("piccode");

UserManager um = new UserManagerImpl();
User u = new User();
boolean flag= false;
try {
flag = um.addm(un, pswd);

} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
if(flag&&checkcode.equals(pickcode)){
response.sendRedirect("logchegngong.jsp");
}

}

}


通过post方法接收来自网页的消息。这里post方法与get方法是有区别的,get方法常用语小于2k内容的信息传递。

然后建立注册的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 'zhuce.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">
-->

</head>

<body>
<h1 align="center">注册新用户</h1>
<hr/>
<form action="add" method="post" align="center" >
用户名:<input name="Username" type="text"/><br/>
<p></p>
密 码:<input name="Password" type="password"/><br/>
<p></p>
验证码:<input name="Code" type="text"><br/>
<p></p>
<input type="submit" style="width:80px; height:35px "value="注册" />
</form>
<a href="index.jsp">返回 </a>
</body>
</html>


与登陆一致,需要建立相应的servlet去接收消息,:

public class add extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

doPost(request, response);
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

request.setCharacterEncoding("utf-8");
response.setCharacterEncoding("utf-8");

int username = Integer.parseInt(request.getParameter("Username"));
String pswd = request.getParameter("Password");
String code = request.getParameter("Code");

UserManager um =new  UserManagerImpl();
User u = new  User();

u.setUsername(username);
u.setPassword(pswd);
u.setCode(code);

boolean flag= false;

try {
flag = um.add(u);
if(flag==true){
response.sendRedirect("index.jsp");
}

} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}

}


这样登录和注册页面就可以完成了。这里再说一下关于验证码的问题。

验证码用于恶意登录。

刚刚在登录页面我们已经写了它的界面,这里需要建立一个相应的servlet他就可以正常运行了。

public class ImagerServelt extends HttpServlet {

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

//1、BufferedImage图像数据缓冲区
BufferedImage bi = new BufferedImage(70, 40, BufferedImage.TYPE_INT_RGB);

//2、Graphics绘制图片

Graphics g = bi.getGraphics();
//3、Color获取颜色

Color c =  new  Color(80,10,50);
g.setColor(c);
g.fillRect(0, 0, 70, 40);

char ch[] = "ABCDEFGHIJK123456789".toCharArray();
StringBuffer sb = new StringBuffer();

//4、Random生成随机数
Random r = new Random();

for (int i = 0; i < 4; i++) {

int index = r.nextInt(ch.length);
g.setColor(new Color(r.nextInt(255),r.nextInt(255),r.nextInt(255)));

g.drawString(ch[index]+"", i*15+3, 20);
sb.append(ch[index]);
}

request.getSession().setAttribute("piccode", sb.toString());
ImageIO.write(bi, "JGP", response.getOutputStream());

}

}

最后把工程截图发上来。


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