JavaWeb學習筆記--day14--註冊案例

day13複習

功能分析

頁面及功能概述
JSP：
login.jsp 登錄頁面
regist.jsp 註冊頁面，服務器表單驗證，註冊成功添加跳轉到登錄的超鏈接，驗證碼
Servlet
RegistServlet
VerifyCodeServlet
Service
UserException 用戶異常
UserService 與用戶相關的業務類
VerifyCode 驗證碼類，個人編寫的，也可以使用itcast包中的驗證碼類
Dao：
JdbcUtils 數據庫連接工具類，單例模式
UserDao 與用戶相關的數據類
Domain：
User（對應數據庫，還要對應表單）
所導jar包

項目目錄結構

數據庫設計
略，選用SQLServer，UserDemo數據庫中Users(username,password)表

註冊流程圖

Domain層實現

user類

/*
 * dao-與用戶相關的實體類
 * 對應數據庫，還對應相應表單
 */
public class User {
	private String username;
	private String password;
	private String verifyCode;
	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 String getVerifyCode() {
		return verifyCode;
	}
	public void setVerifyCode(String verifyCode) {
		this.verifyCode = verifyCode;
	}
	public User() {
		super();
	}
	public User(String username, String password, String verifyCode) {
		super();
		this.username = username;
		this.password = password;
		this.verifyCode = verifyCode;
	}
	@Override
	public String toString() {
		return "User [username=" + username + ", password=" + password + ", verifyCode=" + verifyCode + "]";
	}
	
}

Dao層實現

JdbcUtils類

/*
 * 連接SQLServer數據庫的工具類
 * 單例模式
 */
public final class JdbcUtils {
	private String url = "jdbc:sqlserver://127.0.0.1:1433;DatabaseName=UserDemo";
	private String user = "sa";
	private String password = "123456";
	private JdbcUtils() {
		super();
	}
	private static JdbcUtils instance = null;
	//獲取實例
	public static JdbcUtils getInstance() {
		if(instance==null) {
			synchronized (JdbcUtils.class) {//併發知識 加鎖
				if(instance==null) {//雙重檢查 
					instance=new JdbcUtils();//延遲加載			
				}
			}
		}	
		return instance;
	}
	//靜態代碼段，實現註冊驅動
	static {
		try {
			Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
		} catch (Exception e) {
			// TODO: handle exception
			throw new ExceptionInInitializerError(e);
		}
	}
	//獲得連接
	public Connection getConnection() throws SQLException {
		return DriverManager.getConnection(url, user, password);
	}
	//釋放資源
	public void free(ResultSet rs, PreparedStatement psmt, Connection con) {
		try {
			if(rs!=null)
			rs.close();
		} catch (SQLException e) {
			e.printStackTrace();
		} finally {
			try {
				psmt.close();
			} catch (SQLException e) {
				e.printStackTrace();
			} finally {
				try {
					con.close();
				} catch (SQLException e) {
					e.printStackTrace();
				}
			}
		}
	}
}

UserDao類

/*
 * 與用戶相關的數據類
 */
public class UserDao {
	/*
	 * 根據用戶名查詢
	 * 1.調用JdbcUtils獲得連接
	 * 2.得到prepareStatement
	 * 3.對佔位符進行設值
	 * 4.得到結果並處理
	 * 5.釋放資源
	 */
	public User searchUser(String username) {
		Connection con = null;
		PreparedStatement psmt = null;
		ResultSet rs = null;
		String sql = "select * from users where username like ?";
		JdbcUtils ju = JdbcUtils.getInstance();
		try {
			con = ju.getConnection();
			psmt=con.prepareStatement(sql);
			psmt.setString(1, username);
			rs = psmt.executeQuery();
			User u = new User();
			while(rs.next()) {
				u.setUsername(rs.getString(1));
				u.setPassword(rs.getString(2));
			}
			return u;
		} catch (SQLException e) {
			// TODO Auto-generated catch block
			throw new RuntimeException(e);
		} finally {
			ju.free(rs, psmt, con);
		}
	}
	/*
	 * 插入用戶
	 */
	public void addUser(User user) {
		Connection con = null;
		PreparedStatement psmt = null;
		ResultSet rs = null;
		JdbcUtils ju = JdbcUtils.getInstance();
		String addSql = "insert into users values(?,?)";
		try {
			con = ju.getConnection();
			psmt= con.prepareStatement(addSql);
			psmt.setString(1, user.getUsername());
			psmt.setString(2, user.getPassword());
			psmt.execute();
			System.out.println("插入成功");
		} catch (Exception e) {
			// TODO: handle exception
			throw new RuntimeException(e);
		} finally {
			ju.free(rs, psmt, con);
		}
	}
}

Service層實現

UserException類

/*
 * 用戶異常類
 */
public class UserException extends Exception {

	public UserException() {
		// TODO Auto-generated constructor stub
	}

	public UserException(String arg0) {
		super(arg0);
		// TODO Auto-generated constructor stub
	}

	public UserException(Throwable arg0) {
		super(arg0);
		// TODO Auto-generated constructor stub
	}

	public UserException(String arg0, Throwable arg1) {
		super(arg0, arg1);
		// TODO Auto-generated constructor stub
	}
}

UserService

public class UserService {
	UserDao ud =new UserDao();
	/*
	 * 註冊功能
	 * 使用用戶名去查詢，如果返回null，完成添加
	 * 如果返回不是空 拋出異常
	 */
	public void regist(User user) throws UserException {
		User _user = ud.searchUser(user.getUsername());
		if(_user.getUsername()!=null) throw new UserException("用戶名"+user.getUsername()+"已被註冊");
		ud.addUser(user);
	}
}

VerifyCode類

public class VerifyCode {
	private int w = 70;
	private int h = 35;
	private Random r = new Random();
	private String[] fontNames = {"宋體","華文楷體","微軟雅黑","楷體_GB2312"};
	//可選字符,無1liI;
	private String codes = "23456789abcdefghjkmnopqrstuvwxyzABCDEFGHJKLMNOPQRSTUVWXYZ";
	//背景色
	private Color bgColor = new Color(255,255,255);
	//驗證碼上的文本
	private String text;
	
	//隨機獲得顏色
	private Color randomColor() {
		int R = r.nextInt(150);
		int G = r.nextInt(150);
		int B = r.nextInt(150);
		return new Color(R,G,B);
	}
	//獲得隨機字體
	private Font randomFont() {
		int index = r.nextInt(fontNames.length);//隨機得到字體數組中的一個
		String fontName = fontNames[index];
		int style = r.nextInt(4);//生成隨機樣式：0(無樣式),1(粗體),2(斜體),3(粗體加斜體)
		int size = r.nextInt(5)+24;//生成隨機字號,24~28
		return new Font(fontName, style, size);
	}
	
	//畫干擾線
	private void drawLine (BufferedImage image) {
		int num = 3;//一共畫三條
		Graphics2D g2 = (Graphics2D) image.getGraphics();
		for (int i = 0; i < num; i++) {//生成兩個點的座標
			int x1 = r.nextInt(w);
			int y1 = r.nextInt(h);
			int x2 = r.nextInt(w);
			int y2 = r.nextInt(h);
			g2.setStroke(new BasicStroke(1.5F));
			g2.setColor(Color.BLUE);//藍色干擾線
			g2.drawLine(x1, y1, x2, y2);//畫線
		}
	}
	
	//隨機生成一個字符
	private char randomChar() {
		int index = r.nextInt(codes.length());
		return codes.charAt(index);//獲取字符串的第index個字符
	}
	
	private BufferedImage createImg() {
		BufferedImage image = new BufferedImage(w,h,BufferedImage.TYPE_INT_RGB);
		Graphics2D g2 = (Graphics2D) image.getGraphics();
		g2.setColor(this.bgColor);
		g2.fillRect(0, 0, w, h);
		return image;
	}
	
	//調用這個方法得到驗證碼
	public BufferedImage getImg() {
		BufferedImage image = createImg();//創建圖片緩衝區
		Graphics2D g2 = (Graphics2D) image.getGraphics();//得到繪製環境
		StringBuilder sb = new StringBuilder();//用來裝載生成的驗證碼文本
		//向圖片中畫4個字符
		for (int i = 0; i < 4; i++) {
			String s =randomChar() + "";//隨機生成一個字母
			sb.append(s);//把字母添加到sb中
			float x = i*1.0F *w/4;//設置當前字符的x軸座標
			g2.setFont(randomFont());//設置隨機字體
			g2.setColor(randomColor());//設置隨機顏色
			g2.drawString(s, x, h-5);//畫圖
		}
		this.text = sb.toString();//把生成的字符串賦給this.text
		drawLine(image);//添加干擾線
		return image;
	}
	
	//返回驗證碼圖片上的文本
	public String getText() {
		return text;
	}
	
	//保存圖片到指定的輸出流
	public static void output(BufferedImage image, OutputStream out) throws IOException {
		ImageIO.write(image,"JPEG",out);
	}
}

Servlet層實現

VerifyCode類

@WebServlet("/VerifyCodeServlet")
public class VerifyCodeServlet extends HttpServlet {
	@Override
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		//生成圖片
		//保存圖片上的文本到Session域中
		//把圖片響應給客戶端
		VerifyCode vc = new VerifyCode();
		BufferedImage bi = vc.getImg();
		VerifyCode.output(bi, response.getOutputStream());
		request.getSession().setAttribute("session_code", vc.getText());
	}
}

RegistServlet類

@WebServlet("/RegistServlet")
public class RegistServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//處理編碼
		request.setCharacterEncoding("utf-8");
		response.setContentType("text/html;charset=utf-8");
			
		//依賴UserService
		UserService us =new UserService();
		
		/*
		 * 封裝表單數據到User對象中
		 * 
		 */
		User form = CommonUtils.toBean(request.getParameterMap(), User.class);
		
		/*
		 * 服務器端表單驗證
		 * 1.創建一個Map，用來裝載所有表單錯誤信息
		 * 2.在校驗過程中，如果失敗，向map添加錯誤信息，其中key爲表單字段名
		 * 3.校驗之後查看map長度是否大於0，如果大於零證明有錯誤信息，保存map到request中，
		 * 4.保存form到request中，轉發到regist.jsp中
		 * 5.如果map爲空，向下執行
		 */
		Map<String,String> errors = new HashMap<String,String>();
		//用戶名格式校驗
		String username = form.getUsername();//獲取表單中的username
		if(username == null||username.trim().isEmpty()) {
			errors.put("username", "用戶名不能爲空！");
		}else if(username.length() < 3||username.length() > 15) {
			errors.put("username", "用戶名長度必須在3~15之間！");
		}
		//密碼格式校驗
		String password = form.getPassword();//獲取表單中的password
		if(password == null||password.trim().isEmpty()) {
			errors.put("password", "密碼不能爲空！");
		}else if(password.length() < 3||password.length() > 15) {
			errors.put("password", "密碼長度必須在3~15之間！");
		}
		
		//對驗證碼進行校驗
		String sessionCode = (String)request.getSession().getAttribute("session_code");
		String verifyCode = form.getVerifyCode();//獲取表單中的VerifyCode
		if(verifyCode == null||verifyCode.trim().isEmpty()) {
			errors.put("verifyCode", "驗證碼不能爲空！");
		}else if(verifyCode.length() != 4) {
			errors.put("verifyCode", "驗證碼長度必須爲4！");
		}else if(verifyCode.equalsIgnoreCase(sessionCode) ) {
			errors.put("verifyCode", "驗證碼錯誤！");
		}
		
		//判斷map是否爲空，不爲空說明有問題
		if(errors != null && errors.size() > 0) {//健壯性
			/*
			 * 1.保存errors到request域
			 * 2.保存form到request域，用於回顯
			 * 3.轉發到regist.jsp
			 */
			request.setAttribute("errors", errors);
			request.setAttribute("user", form);
			request.getRequestDispatcher("/user/regist.jsp").forward(request, response);
			return;
			
		}
		/*
		 * 調用us的方法 傳遞form過去
		 * 得到異常：獲取異常信息，保存到request域中，轉發到regist.jsp中顯示
		 * 沒有異常：輸出註冊成功
		 */
		try {
			us.regist(form);
			response.getWriter().print("<h2>註冊成功！</h2> <a href='" + 
			request.getContextPath()+"/user/login.jsp" + 
			"'>點擊這裏去登陸</a>");
		} catch (UserException e) {
			//獲取異常信息保存到request域中,並且轉發到註冊頁面
			request.setAttribute("msg", e.getMessage());
			request.setAttribute("user", form);//用來在表單中回顯,EL表達式特點，沒有啥也不顯示，不是NULL
			request.getRequestDispatcher("/user/regist.jsp").forward(request, response);
		}
	}
}

頁面代碼實現

regist.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>    
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
function _change(){
	/*
	得到img元素
	修改其src爲/LoginDemo/VerifyCodeServet
	*/
	var imgEle = document.getElementById("img");
	imgEle.src = "${pageContext.request.contextPath }/VerifyCodeServlet?a="+new Date().getTime();//不加個時間會因爲瀏覽器緩存而更換失敗
}
</script>
</head>
<body>
<%--<c:url value='/RegistServlet'/> --%>
<%--${pageContext.request.contextPath }/RegistServlet --%>
<%
	String message = " ";
	String msg = (String)request.getAttribute("msg");
	if(msg !=null){
		message = msg;
	}
%>
<h1>註冊</h1>
<font color="red"><b><%= message%></b></font>
<form method="post" action="${pageContext.request.contextPath }/RegistServlet">
用戶名：<input type="text" name="username" value="${user.username}"/>${errors.username }<br/>
密  碼：<input type="password" name="password" value="${user.password}"/>${errors.password }<br/>
驗證碼:<input type="text" name="verifyCode" size="3"/>
<img id="img" src="${pageContext.request.contextPath }/VerifyCodeServlet"/>
<a href="javascript:_change()">換一張</a>${errors.verifyCode }<br/>
<input type="submit" value="註冊" />
</form>
</body>
</html>

login.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
<%--${pageContext.request.contextPath }/LoginServlet --%>
<form method="post" action="<c:url value='/LoginServlet'/>">
用戶名：<input type="text" name="username"/><br/>
密  碼：<input type="password" name="password"/><br/>
<input type="button" value="登錄"/>
</form>
</body>
</html>