LoginCheckServlet.java
package chap05svlt;
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 javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.codec.digest.DigestUtils;
public class LoginCheckServlet extends HttpServlet {
private void loadJDBCDriver() throws ServletException {
try {
Class.forName("org.postgresql.Driver");
} catch (ClassNotFoundException e) {
throw new ServletException(e);
}
}
private Connection getConnection() throws ServletException {
try {
return( DriverManager.getConnection(
"jdbc:postgresql://localhost:5432/BookStore", "okada",
"okada") );
} catch (SQLException e) {
throw new ServletException(e);
}
}
private void closeConnection(Connection con) {
try {
con.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
private static String getStringDigest( String inString ){
return( DigestUtils.md5Hex( inString + "digested" ) );
}
private void forward( String dest,
HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
getServletContext().getRequestDispatcher(dest).forward(request, response);
}
public void init() throws ServletException {
loadJDBCDriver();
}
protected void doPost( HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
String account = request.getParameter("account");
String password = request.getParameter("password");
String password_db;
String email;
String name;
Connection con = getConnection();
try {
PreparedStatement ps = con.prepareStatement(
"select * from t_customer where uid like ?;");
ps.setString(1, account);
ResultSet rs = ps.executeQuery();
if (!rs.next()) {
throw new ServletException("no account");
}
password_db = rs.getString("passwordmd5");
email = rs.getString("email");
name = rs.getString("name");
if (rs.next()) {
throw new ServletException("too many accounts found");
}
rs.close();
ps.close();
} catch (SQLException e) {
throw new ServletException(e);
} finally {
closeConnection(con);
}
if (password_db.equals( getStringDigest(password) )) {
request.setAttribute("email", email);
request.setAttribute("name", name);
forward("/result.jsp", request, response);
} else {
forward("/index.html", request, response);
}
}
}index.html
<html>
<head></head>
<body>
ユーザID、パスワードを入力してください。<br>
<br>
<form action="/Chap05Svlt/LoginCheckServlet" method="POST">
ユーザID: <input type="text" name="account"> <br>
パスワード: <input type="password" name="password"> <br>
<input type="submit" value="submit">
</form>
</body>
</html>result.jsp
<%@ page language="java" contentType="text/html;charset=Windows-31J" %> <html> <head> <title></title> </head> <body> あなたは、 <br> 氏名: <%= request.getAttribute( "name" ) %> <br> アカウント: <%= request.getParameter( "account" ) %><br> E-Mail: <%= request.getAttribute( "email" ) %> <br> <a href="/Chap05Svlt/index.html">トップ</a>へ戻る。 </body> </html>
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
<display-name>Chap05Svlt</display-name>
<welcome-file-list>
<welcome-file>index.html</welcome-file>
</welcome-file-list>
<servlet>
<description></description>
<display-name>LoginCheckServlet</display-name>
<servlet-name>LoginCheckServlet</servlet-name>
<servlet-class>chap05svlt.LoginCheckServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginCheckServlet</servlet-name>
<url-pattern>/LoginCheckServlet</url-pattern>
</servlet-mapping>
</web-app>
所需類包：
commons-codec-1.3.jar
postgresql-8.3-603.jdbc3.jar
代碼來自日本的技術圖書 ：http://www.shuwasystem.co.jp/products/7980html/2197.html