struts登录系统实现
在java ee中讲了第一个web实例，具体见博文：http://hnzhoujunmei.iteye.com/admin/blogs/1004827
非常简单的一个实例，没有数据库连接，本实例在这个实例基础上添加struts功能和数据库功能
在上一个实例基础上用myeclipse的添加struts功能，即生成了一个struts的资源文件，
ApplicationResources.properties：

# Resources for parameter 'com.qdu.struts.ApplicationResources'# Project strustLoginDemo#message filelogin.username=username is null!login.password=password is null!

项目的目录结构：




注意该文件不能写入中文。可以使用java中的native2ascii.exe将中文转换为字符串。
然后新建Action，Form等，并可在可视化环境下进行配置，如form的属性等
Action类：

/* * Generated by MyEclipse Struts * Template path: templates/java/JavaClass.vtl */package com.qdu.struts.action;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.apache.struts.action.Action;import org.apache.struts.action.ActionForm;import org.apache.struts.action.ActionForward;import org.apache.struts.action.ActionMapping;import com.qdu.struts.BO.LoginBO;import com.qdu.struts.form.LoginForm;/**  * MyEclipse Struts * Creation date: 04-14-2011 *  * XDoclet definition: * @struts.action path="/login" name="loginForm" input="/login.jsp" scope="request" validate="true" * @struts.action-forward name="failed" path="/fail.jsp" * @struts.action-forward name="success" path="/success.jsp" */public class LoginAction extends Action {/* * Generated Methods *//**  * Method execute * @param mapping * @param form * @param request * @param response * @return ActionForward */public ActionForward execute(ActionMapping mapping, ActionForm form,HttpServletRequest request, HttpServletResponse response) {LoginForm loginForm = (LoginForm) form;// TODO Auto-generated method stub//        调用业务处理类LoginBO login = new LoginBO();if(login.validate(loginForm.getUsername(),loginForm.getPassword())){request.setAttribute("username", loginForm.getUsername());return mapping.findForward("success");}else return mapping.findForward("failed");}}

业务逻辑类：

package com.qdu.struts.BO;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;public class LoginBO {public boolean validate(String username, String password) {Connection conn = null;try {Class.forName("org.gjt.mm.mysql.Driver");String url = "jdbc:mysql://localhost:3306/junit";conn = DriverManager.getConnection(url,"root","root");Statement stmt = conn.createStatement();String sql = "select * from usertable where name='"+username+"' and password = '"+password+"'";ResultSet rs = stmt.executeQuery(sql);if(rs.next()){return true;}else return false;} catch (ClassNotFoundException e) {e.printStackTrace();} catch (SQLException e) {e.printStackTrace();}return false;}}

表单类：

/* * Generated by MyEclipse Struts * Template path: templates/java/JavaClass.vtl */package com.qdu.struts.form;import javax.servlet.http.HttpServletRequest;import org.apache.struts.action.ActionErrors;import org.apache.struts.action.ActionForm;import org.apache.struts.action.ActionMapping;import org.apache.struts.action.ActionMessage;/** * MyEclipse Struts Creation date: 04-14-2011 *  * XDoclet definition: *  * @struts.form name="loginForm" */public class LoginForm extends ActionForm {/* * Generated fields *//** password property */private String password;/** username property */private String username;/* * Generated Methods *//** * Method validate *  * @param mapping * @param request * @return ActionErrors */public ActionErrors validate(ActionMapping mapping,HttpServletRequest request) {//验证，相当于JavaScript的验证ActionErrors errors = new ActionErrors();if (this.username == null || this.username.length() < 1)errors.add("username", new ActionMessage("login.username"));if (this.password == null || this.username.length() < 1)errors.add("password", new ActionMessage("login.password"));return errors;}/** * Method reset *  * @param mapping * @param request */public void reset(ActionMapping mapping, HttpServletRequest request) {// TODO Auto-generated method stubthis.username = null;this.password = null;}/** * Returns the password. *  * @return String */public String getPassword() {return password;}/** * Set the password. *  * @param password *            The password to set */public void setPassword(String password) {this.password = password;}/** * Returns the username. *  * @return String */public String getUsername() {return username;}/** * Set the username. *  * @param username *            The username to set */public void setUsername(String username) {this.username = username;}}

struts配置文件：

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.2//EN" "http://struts.apache.org/dtds/struts-config_1_2.dtd"><struts-config>  <data-sources />  <form-beans >    <form-bean name="loginForm" type="com.qdu.struts.form.LoginForm" />  </form-beans>  <global-exceptions />  <global-forwards />  <action-mappings >    <action      attribute="loginForm"      input="/login.jsp"      name="loginForm"      path="/login"      scope="request"      type="com.qdu.struts.action.LoginAction">      <forward name="failed" path="/fail.jsp" />      <forward name="success" path="/success.jsp" />    </action>  </action-mappings>  <message-resources parameter="com.qdu.struts.ApplicationResources" /></struts-config>

web.xml：

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.5" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee   http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">  <servlet>    <servlet-name>action</servlet-name>    <servlet-class>org.apache.struts.action.ActionServlet</servlet-class>    <init-param>      <param-name>config</param-name>      <param-value>/WEB-INF/struts-config.xml</param-value>    </init-param>    <init-param>      <param-name>debug</param-name>      <param-value>3</param-value>    </init-param>    <init-param>      <param-name>detail</param-name>      <param-value>3</param-value>    </init-param>    <load-on-startup>0</load-on-startup>  </servlet>  <servlet-mapping>    <servlet-name>action</servlet-name>    <url-pattern>*.do</url-pattern>  </servlet-mapping>  <welcome-file-list>    <welcome-file>index.jsp</welcome-file>  </welcome-file-list>    <filter>  <filter-name> FormFilter</filter-name>  <filter-class>com.qdu.struts.BO.FormFilter</filter-class>  </filter>  <filter-mapping>  <filter-name>FormFilter</filter-name>  <url-pattern>/*</url-pattern>  </filter-mapping>  </web-app>