We will create a Web application of login based on Struts 2 framework in Eclipse:
- a login page enabling to enter username/password, a submit button
- when the submit button is clicked, the server receives the username/password and verifies it from the DB on the server.
- if the login is success, a success page will appear
- otherwise, a failure page is displayed.
Project development
Create a project (to see how to create a Web project and download Struts 2 library, please see: http://coderandcode.blogspot.com/2013/10/helloworld-simple-web-application-with.html) with folders and files in the project directory as follow:
- in the src folder, create two packages: control and model. In package control, create two java classes of name LoginAction and UserDAO. In package model, create a java class of name User.
- add a resource folder into project directory and create a file: ApplicationResources.properties
- in the WebContent folder, create two JSP pages: login and success.
- in the WebContent/WEB-INF/ folder, create a file web.xml
- in the WebContent/WEB-INF/classes folder, create a file struts.xml
Now we have to define all java classes, jsp pages, .property file, and .xml files
User.java
package model;
import java.io.Serializable;
public class User implements Serializable{
private static final long serialVersionUID = 1L;
private String username;
private String password;
public User(){
}
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;
}
}
UserDAO.java
package control;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import model.User;
public class UserDAO {
private Connection con = null;
private Statement st = null;
private ResultSet rs = null;
private String url = "jdbc:mysql://localhost:3306/hotelmanagement";
private String user = "root";
private String password = "12345678";
public UserDAO(){
try {
Class.forName("com.mysql.jdbc.Driver");
con = DriverManager.getConnection(url, user, password);
st = con.createStatement();
rs = st.executeQuery("SELECT VERSION()");
if (rs.next()) {
System.out.println(rs.getString(1));
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
public boolean checkLogin(User user){
boolean result = false;
try {
st = con.createStatement();
String sql= "SELECT * FROM tbluser WHERE username = ? AND password = ?";
PreparedStatement prs = con.prepareStatement(sql);
prs.setString(1, user.getUsername());
prs.setString(2, user.getPassword());
rs = prs.executeQuery();
if (rs.next()) {
result = true;
}
} catch (SQLException ex) {
ex.printStackTrace();
}
return result;
}
}
LoginAction.java
package control;
import model.User;
import com.opensymphony.xwork2.ActionSupport;
public class LoginAction extends ActionSupport{
private static final long serialVersionUID = 2L;
private User userBean;
public String execute() throws Exception {
UserDAO ud = new UserDAO();
if (ud.checkLogin(userBean)) {
return "success";
} else {
addActionError(getText("error.login"));
return "input";
}
}
public void validate(){
//The addFieldError method takes two arguments.
//The first is the form field name to which the error applies
//and the second is the error message to display above that form field.
if ( userBean.getUsername().length() == 0 ){
addFieldError( "userBean.username", "Username is required." );
}
if ( userBean.getPassword().length() == 0 ){
addFieldError( "userBean.password", "Password is required." );
}
}
public User getUserBean() {
return userBean;
}
public void setUserBean(User userBean) {
this.userBean = userBean;
}
}
ApplicationResources.properties
label.username= Username
label.password= Password
label.login= Login
error.login = Username and password incorrect! Try again...
login.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<html>
<head>
<title>Struts 2 - Login Application</title>
</head>
<body>
<h2>Struts 2 - Login Application</h2>
<s:actionerror />
<s:form action="login" method="post">
<s:textfield name="userBean.username" key="label.username" size="20" />
<s:password name="userBean.password" key="label.password" size="20" />
<s:submit method="execute" key="label.login" align="center" />
</s:form>
</body>
</html>
success.jsp
<%@ page contentType="text/html; charset=UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<html>
<head>
<title>Welcome</title>
</head>
<body>
<h2>Hi, <s:property value="userBean.username" />!</h2>
</body>
</html>
web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_9" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<display-name>Struts Blank</display-name>
<filter>
<filter-name>struts2</filter-name>
<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<welcome-file-list>
<welcome-file>login.jsp</welcome-file>
</welcome-file-list>
</web-app>
struts.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<constant name="struts.devMode" value="true" />
<constant name="struts.custom.i18n.resources" value="ApplicationResources" />
<package name="basicstruts2" extends="struts-default">
<action name="index">
<result>/login.jsp</result>
</action>
<action name="login" class="control.LoginAction" method="execute">
<result name="success">/success.jsp</result>
<result name="input">/login.jsp</result>
</action>
</package>
</struts>
Results
- login page:
- success page:
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