struts做的记录当前在线用户，不可重复登录，并且可对在线用户进行强制下线

本文主要是做了一个登录的简单实现功能，其中的实体类，管理类都是之前我那个学生信息管理系统的 大家翻翻以前的文章应该可以找到，这里 我还是重新发个完整的。

struts的配置我就不说了，在上一篇文章做了详细说明了。

先给大家发一张例子各种包的截图，方便大家一目了然的知道例子中的基本包（com.test是我测试代码用的 大家可以无视掉）

 



一、com.action包中的类 action作为中间层，和V层之间进行交互

①LoginAction.java 

package com.action;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpSession;

import org.apache.struts2.ServletActionContext;

import com.jdbc.entity.UserInfoEntity;
import com.jdbc.manager.SchoolManager;
import com.opensymphony.xwork2.ActionContext;

public class LoginAction {

private UserInfoEntity user;

public UserInfoEntity getUser() {
return user;
}

public void setUser(UserInfoEntity user) {
this.user = user;
}
public LoginAction() {

}
public String execute(){
ActionContext act=ActionContext.getContext();
Map appmap=act.getApplication();

HttpSession session=ServletActionContext.getRequest().getSession();
Map<UserInfoEntity, HttpSession> uol=(Map<UserInfoEntity, HttpSession>) appmap.get("useronline");
if(uol==null){
uol=new HashMap<UserInfoEntity, HttpSession>();
appmap.put("useronline",uol);
}
Set<UserInfoEntity> keyset=uol.keySet();
for (UserInfoEntity user: keyset) {
if(user.getLogname().equals(this.user.getLogname())){
return "unsuccess";
}
}
user=SchoolManager.checkLogin(user);
if(user==null){
return "unsuccess";
}
act.getSession().put("user", this.user);
uol.put(this.user,session);

return (user!=null)?"success":"unsuccess";
}

}

 

②LoginOutAction.java

 

package com.action;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import javax.servlet.http.HttpSession;

import com.jdbc.entity.UserInfoEntity;
import com.opensymphony.xwork2.ActionContext;

public class LoginOutAction {

private String sessionid;

public String getSessionid() {
return sessionid;
}

public void setSessionid(String sessionid) {
this.sessionid = sessionid;
}
public LoginOutAction() {
// TODO Auto-generated constructor stub
}
public String execute(){
ActionContext act=ActionContext.getContext();
Map appmap=act.getApplication();
Map<UserInfoEntity, HttpSession> uol=(Map<UserInfoEntity, HttpSession>) appmap.get("useronline");
Set<UserInfoEntity> keyset=uol.keySet();
Iterator<UserInfoEntity> it=keyset.iterator();
while(it.hasNext()){
UserInfoEntity key=it.next();
HttpSession session=uol.get(key);
if(session.getId().equals(sessionid)){
session.invalidate();
it.remove();

}
}
//		HashMap<String, HttpSession> sessionmap=(HashMap<String, HttpSession>) appmap.get("sessionmap");
//		sessionmap.get(sessionid).invalidate();

return "success";
}
}

 

二、com.control包中的类 监听器负责处理session

①SysListener.java

package com.control;

import java.util.HashMap;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionContext;
import javax.servlet.http.HttpSessionEvent;
import javax.servlet.http.HttpSessionListener;

public class SysListener  implements HttpSessionListener{

public void sessionCreated(HttpSessionEvent se) {
HttpSession session=se.getSession();
ServletContext application=session.getServletContext();

HashMap<String,HttpSession> sessionmap=(HashMap<String, HttpSession>) application.getAttribute("sessionmap");
if(sessionmap==null){
sessionmap=new HashMap<String,HttpSession>();
application.setAttribute("sessionmap", sessionmap);
}
sessionmap.put(session.getId(),session);

}

public void sessionDestroyed(HttpSessionEvent se) {
HttpSession session=se.getSession();
ServletContext application=session.getServletContext();

HashMap<String,HttpSession> sessionmap=(HashMap<String, HttpSession>) application.getAttribute("sessionmap");
if(sessionmap==null){
sessionmap=new HashMap<String,HttpSession>();
}
session.removeAttribute(session.getId());
}

}

三、com.jdbc.entity包中的类

①UserInfoEntity.java  用户实体类

package com.jdbc.entity;

import java.math.BigDecimal;
import java.sql.Timestamp;

import com.jdbc.manager.SchoolManager;

public class UserInfoEntity {

private BigDecimal userid;
private String logname;
private String keyword;
private UserTypeEntity usertype;
private BigDecimal utstate;
private BigDecimal utid;
public BigDecimal getUserid() {
return userid;
}
public void setUserid(BigDecimal userid) {
this.userid = userid;
}
public String getLogname() {
return logname;
}
public void setLogname(String logname) {
this.logname = logname;
}
public String getKeyword() {
return keyword;
}
public void setKeyword(String keyword) {
this.keyword = keyword;
}
public UserTypeEntity getUsertype() {
UserTypeEntity type=SchoolManager.getUserTypeInfoById(utid);
if(type!=null){
return this.usertype=type;
}else{
return this.usertype;
}
}
public void setUsertype(UserTypeEntity usertype) {
this.usertype = usertype;
}
public BigDecimal getUtstate() {
return utstate;
}
public void setUtstate(BigDecimal utstate) {
this.utstate = utstate;
}
public UserInfoEntity(BigDecimal userid, String logname, String keyword,
UserTypeEntity usertype, BigDecimal utstate) {
super();
this.userid = userid;
this.logname = logname;
this.keyword = keyword;
this.usertype = usertype;
this.utstate = utstate;
}
public UserInfoEntity(BigDecimal userid, String logname, String keyword,
BigDecimal utid, BigDecimal utstate) {
super();
this.userid = userid;
this.logname = logname;
this.keyword = keyword;
this.utid=utid;
this.utstate = utstate;
}
public UserInfoEntity() {
}
}

四、com.jdbc.manager

①SchoolManager.java 我直接把以前的拷贝过来 。大家只看用户的就行了

package com.jdbc.manager;

import java.math.BigDecimal;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;

import com.jdbc.entity.ClassInfoEntity;
import com.jdbc.entity.PopEntity;
import com.jdbc.entity.StudentEntity;
import com.jdbc.entity.TeacherEntity;
import com.jdbc.entity.UserInfoEntity;
import com.jdbc.entity.UserTypeEntity;
import com.jdbc.entity.Ut_and_PopEntity;
import com.jdbc.service.ClassInfoService;
import com.jdbc.service.PopService;
import com.jdbc.service.StudentService;
import com.jdbc.service.TeacherService;
import com.jdbc.service.UserInfoService;
import com.jdbc.service.UserTypeService;
import com.jdbc.service.Ut_and_PopService;
import com.jdbc.tool.DBHelper;

public class SchoolManager {

private static TeacherService teacherManager=new TeacherService();
private static ClassInfoService classManager=new ClassInfoService();
private static StudentService studentManager=new StudentService();
private static UserInfoService userManager=new UserInfoService();
private static UserTypeService utManager=new UserTypeService();
private static PopService popManager=new PopService();
private static Ut_and_PopService upManager=new Ut_and_PopService();
/**
* 添加新教师信息
* @param entity 添加教师的实体
* @return 成功返回true，失败返回false
*/
public static boolean addNewTeacherInfo(Object entity){
return teacherManager.insertInfo(entity);
}
public static boolean delTeacherInfoById(Object id){
return teacherManager.deleteInfo(id);
}
public static boolean updTeacherInfo(Object entity){
return teacherManager.updateInfo(entity);
}
public static TeacherEntity getTeacherInfoById(Object id){
return teacherManager.getAllInfoById(id);
}
public static List<TeacherEntity> getAllTeacherInfo(){
return teacherManager.getAllInfo();
}
public static List<TeacherEntity> getAllTeacherInfoByPageSize(int pagesize,int rowcount){
return teacherManager.getAllInfoByPageSize(pagesize, rowcount);
}
public static int getTeacherPagesize(int rowcount){
return teacherManager.getPageSize(rowcount);
}
/**
* 根据班级ID，删除班级信息
* @param id
* @return
*/
public static boolean addNewClassInfo(Object entity){
return classManager.insertInfo(entity);
}
public static boolean delClassInfoById(Object id){
return classManager.deleteInfo(id);
}
public static boolean updClassInfo(Object entity){
return classManager.updateInfo(entity);
}
public static ClassInfoEntity getClassInfoById(Object id){
return classManager.getAllInfoById(id);
}
public static List<ClassInfoEntity> getAllClassInfo(){
return classManager.getAllInfo();
}
public static List<ClassInfoEntity> getAllClassInfoByPageSize(int pagesize,int rowcount){
return classManager.getAllInfoByPageSize(pagesize, rowcount);
}
public static int getClassPagesize(int rowcount){
return classManager.getPageSize(rowcount);
}
//学生信息
public static boolean addNewStudentInfo(Object entity){
return studentManager.insertInfo(entity);
}
public static boolean delStudentInfoById(Object id){
return studentManager.deleteInfo(id);
}
public static boolean updStudentInfo(Object entity){
return studentManager.updateInfo(entity);
}
public static StudentEntity getStudentInfoById(Object id){
return studentManager.getAllInfoById(id);
}
public static List<StudentEntity> getAllStudentInfo(){
return studentManager.getAllInfo();
}
public static List<StudentEntity> getAllStudentInfoByPageSize(int pagesize,int rowcount){
return studentManager.getAllInfoByPageSize(pagesize, rowcount);
}
public static int getStudentPagesize(int rowcount){
return studentManager.getPageSize(rowcount);
}
//用户信息
public static boolean addNewUserInfo(Object entity){
return userManager.insertInfo(entity);
}
public static boolean delUserInfoById(Object id){
return userManager.deleteInfo(id);
}
public static boolean updUserInfo(Object entity){
return userManager.updateInfo(entity);
}
public static UserInfoEntity getUserInfoById(Object id){
return userManager.getAllInfoById(id);
}
public static UserInfoEntity getUserInfoBylogname(Object id){
return userManager.getAllInfoBylogname(id);
}
public static List<UserInfoEntity> getAllUserInfo(){
return userManager.getAllInfo();
}
public static UserInfoEntity checkLogin(UserInfoEntity user){
List<UserInfoEntity> list=userManager.checkLogin(user);
return (list!=null&&list.size()>0)?list.get(0):null;

}
public static List<UserInfoEntity> getAllUserInfoByPageSize(int pagesize,int rowcount){
return userManager.getAllInfoByPageSize(pagesize, rowcount);
}
public static int getUserPagesize(int rowcount){
return userManager.getPageSize(rowcount);
}
//用户角色
public static boolean addNewUserTypeInfo(Object entity){
return utManager.insertInfo(entity);
}
public static boolean delUserTypeInfoById(Object id){
return utManager.deleteInfo(id);
}
public static boolean updUserTypeInfo(Object entity){
return utManager.updateInfo(entity);
}
public static UserTypeEntity getUserTypeInfoById(Object id){
return utManager.getAllInfoById(id);
}
public static List<UserTypeEntity> getAllUserTypeInfo(){
return utManager.getAllInfo();
}
//权限
public static PopEntity getPopInfoById(Object id){
return popManager.getAllInfoById(id);
}
public static List<PopEntity> getAllPopInfo(){
return popManager.getAllInfo();
}
//中间表
public static List<Ut_and_PopEntity> getPopByUtid(String utid){
return 	upManager.getInfoByUtid(utid);
}
public static boolean addNewUt_and_PopInfo(Object entity){
return upManager.insertInfo(entity);
}
public static boolean delAllUt_and_PopInfo(Object id){
return upManager.deleteInfo(id);
}
public static boolean updatePopOfUserType(UserTypeEntity ut,PopEntity[] pops){
Connection con=DBHelper.getConnection();
if(con==null){
return false;
}
try {
con.setAutoCommit(false);
upManager.deleteInfoByUtid(con, "utid", ut.getUtid());

for (int i = 0; i < pops.length; i++) {
Ut_and_PopEntity up=new Ut_and_PopEntity(ut, pops[i]);
upManager.insertInfo(con, up);
}
con.commit();
return true;
} catch (SQLException e) {
try {
con.rollback();
} catch (SQLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}finally{
DBHelper.closeJDBC(null, null, con);
}

return false;
}

}

五、com.jdbc.service包中的类

①Manager.java 同样也是拷贝的 这是抽出来的方法，供项目中的其他类进行使用

package com.jdbc.service;

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

import com.jdbc.tool.DBHelper;
import com.sun.corba.se.spi.orbutil.fsm.State;

public abstract class Manager {

public abstract boolean insertInfo(Object entity);
public abstract boolean deleteInfo(Object id);
public abstract boolean updateInfo(Object entity);
public abstract Object getAllInfoById(Object id);
public abstract List getAllInfo();

/**
* 根据传入的每页行数返回分页数
* @param tname 要分页的表名
* @param rowcount 每页行数
* @return 分页数
*/
int getPageSize(String tname,int rowcount){
Connection con=DBHelper.getConnection();
if(con==null){
return -1;
}
Statement st=null;
ResultSet rs=null;
try {
st=con.createStatement();
rs=st.executeQuery("select count(*) from "+tname);
int size=-1;
if(rs.next()){
size=rs.getInt(1);
if(size%rowcount==0){
return (size/rowcount);
}

return (size/rowcount)+1;
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
DBHelper.closeJDBC(rs, st, con);
}
return -1;
}
/**
* 用于父类 封装 子类根据对象属性查询的方法
* @param tname  表名
* @param clname  要查询的列名
* @param clvalue 传入的列名的值
* @param cl 用于   指定 实体类  类文件
* @return  查询结果集封装的数据（实体类对象集合）
*/
List getInfoByproperty(String tname,String[] clname,String[] clvalue,Class cl){

String sql="select * from "+tname+" where 0=0 ";
for (int i = 0; i < clname.length; i++) {
sql+=" and "+clname[i]+"=?";
}

return this.getAllInfo(sql, clvalue, cl);

}

/**
*用于父类 封装 增删改 的方法，以外部传取connection作为连接（可控制事务） 不需要关闭connection
*本方方多用于批处理（结合其他业务一起进行操作）
* @param con 外部获取的connection连接
* @param sql 操作的sql指令
* @param args 参数数组
* @return
*/
boolean updateDB(Connection con,String sql,String[] args){
//获取操作指令装置，并执行sql（可赋值）
PreparedStatement ps=null;
try {
ps=con.prepareStatement(sql);
if(args!=null&&args.length>0){
for (int i = 0; i < args.length; i++) {
ps.setString(i+1, args[i]);
}
}
return ps.executeUpdate()>0 ? true:false;
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
DBHelper.closeJDBC(null, ps, null);
}
return false;
}
/**
* 用于父类 封装 增删改 的方法，直接利用重载进行dml的操作（多用于单独执行）
* @param sql 操作的sql指令
* @param args 参数数组
* @return
*/
boolean updateDB(String sql,String[] args){
Connection con=DBHelper.getConnection();
try {
return updateDB(con, sql, args);
} catch (Exception e) {
// TODO: handle exception
}finally{
try {
con.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

return false;
}

/**
* 用于父类 封装 查询 的方法，供子类调用。
* @param sql  查询语句（select .......）
* @param args  查询条件值（可以为null——基本查询）
* @param cl  用于   指定 集合中封装的 实体类  类文件
* @return  查询结果集封装的数据（实体类对象集合）
*/
List getAllInfo(String sql,String[] args,Class cl){
//获取连接并判断
Connection con=DBHelper.getConnection();
//Connection con=DB_helper.getInstance().getConnection();
if(con==null){
return null;
}
//获取操作指令装置，并执行sql（可赋值）
PreparedStatement ps=null;
ResultSet rs=null;
try {
ps=con.prepareStatement(sql);
if(args!=null){
for (int i = 0; i < args.length; i++) {
ps.setString(i+1, args[i]);
}
}
rs=ps.executeQuery();
//获取 rs 的源数据，从中得到操作表的 列数
int colcount=rs.getMetaData().getColumnCount();
//准备构造方法所用参数的数组，长度为 表 列数
Object[] canshu=new Object[colcount];

//封装返回值的容器
List list=new ArrayList();
//遍历 所有指定 实体类的构造方法，用 参数数组去获取 实体类 对象（如成功，则列值被封装成 对象 属性值）
Object ob=null;

//封装返回值的容器
while(rs.next()){
//将一行 表的数据 封装到 参数数组中
for (int i = 0; i < canshu.length; i++) {
canshu[i]=rs.getObject(i+1);
//可用于查看 Oracle数据库对应的 java 数据类型
//System.out.println(canshu[i].getClass());
}
//
ob=getObject(cl, canshu);
//如成功，则将封装有属性值的对象，放入 list 集合
if(ob==null){
return null;
}
//如成功，则将封装有属性值的对象，放入 list 集合
list.add(ob);
}
return new ArrayList(list);
} catch (Exception e) {

}finally{
DBHelper.closeJDBC(rs, ps, con);
}
return null;
}
/**
* 用于自动封装 行数据成为 指定类对象的方法
* @param cl 传进返回的实体类型
* @param canshu 进行参数匹配的数组
* @return 实体类型
*/
private Object getObject(Class cl,Object[] canshu){
Constructor[] cons=cl.getConstructors();
Object ob=null;
for (int i = 0; i < cons.length; i++) {
try {
ob=cons[i].newInstance(canshu);
return ob;
} catch (Exception e) {
continue;
}
}
return null;
}

}

 

②UserInfoService.java

package com.jdbc.service;

import java.util.List;

import javax.xml.registry.infomodel.User;

import com.jdbc.entity.TeacherEntity;
import com.jdbc.entity.UserInfoEntity;

public class UserInfoService extends Manager{

public int getPageSize(int rowcount){
return this.getPageSize("sa.userinfo", rowcount);
}

public List<UserInfoEntity> getAllInfoByPageSize(int pagesize,int rowcount){
String sql="select * from (select * from sa.userinfo where userid not in(select * from (select userid from sa.userinfo where rownum<=(?-1)*? order by userid)) order by userid)where rownum<=?";
String[] args=new String[]{pagesize+"",rowcount+"",rowcount+""};
return this.getAllInfo(sql, args, UserInfoEntity.class);
}
public List<UserInfoEntity> checkLogin(UserInfoEntity user){
return this.getInfoByproperty("sa.userinfo",new String[]{"logname","keyword"},new String[]{user.getLogname(),user.getKeyword()},UserInfoEntity.class);
}
@Override
public boolean deleteInfo(Object id) {
String sql="delete from sa.userinfo where userid=?";
return this.updateDB(sql, new String[]{id+""});
}

@Override
public List getAllInfo() {
String sql="select * from sa.userinfo";
return this.getAllInfo(sql, null, UserInfoEntity.class);
}

@Override
public UserInfoEntity getAllInfoById(Object id) {
String sql="select * from sa.userinfo where userid=?";
List<UserInfoEntity> list=this.getAllInfo(sql, new String[]{id+""},UserInfoEntity.class);
return (list!=null&&list.size()>0)?list.get(0):null;
}
public UserInfoEntity getAllInfoBylogname(Object logname) {
String sql="select * from sa.userinfo where logname=?";
List<UserInfoEntity> list=this.getAllInfo(sql, new String[]{logname+""},UserInfoEntity.class);
return (list!=null&&list.size()>0)?list.get(0):null;
}

@Override
public boolean insertInfo(Object entity) {
UserInfoEntity user=(UserInfoEntity) entity;
String sql="insert into sa.userinfo values(?,?,?,?,?)";
String[] args=new String[]{user.getUserid()+"",user.getLogname(),user.getKeyword(),user.getUsertype().getUtid()+"",user.getUtstate()+""};
return this.updateDB(sql, args);
}

@Override
public boolean updateInfo(Object entity) {
UserInfoEntity user=(UserInfoEntity) entity;
String sql="update sa.userinfo set keyword=?,utid=?,utstate=? where userid=?";
String[] args=new String[]{user.getKeyword(),user.getUsertype().getUtid()+"",user.getUtstate()+"",user.getUserid()+""};
return this.updateDB(sql, args);
}

}

六、com.jdbc.tool包中的类 （连接池）

①DBHelper.java

package com.jdbc.tool;

import java.beans.PropertyVetoException;
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 com.mchange.v2.c3p0.ComboPooledDataSource;

public class DBHelper {

private static ComboPooledDataSource cpds=new ComboPooledDataSource();
//private static OracleDispose od=new OracleDispose("f:/config.properties");
static {
try {
// 驱动器
cpds.setDriverClass("oracle.jdbc.OracleDriver");
// 数据库url
cpds.setJdbcUrl("jdbc:oracle:thin:@127.0.0.1:1521:ORCL");
//cpds.setJdbcUrl(od.jdbcurl);通过properties动态获取文件中存储的jdbcurl
//用户名
cpds.setUser("sa");
//cpds.setUser(od.username);通过properties动态获取文件中存储的用户名称
//密码
cpds.setPassword("sa");
//cpds.setPassword(od.userpwd);通过properties动态获取文件中存储的用户密码
//初始化连接池的大小
cpds.setInitialPoolSize(30);
//最小连接数
cpds.setMinPoolSize(20);
//最大连接数
cpds.setMaxPoolSize(100);
} catch (PropertyVetoException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}
/**
* 用于数据库的链接
* @return 返回Connection
*/
public static Connection getConnection(){

try {
return cpds.getConnection();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
/**
*  用于关闭数据库的关闭
* @param rs ResultSet对象
* @param st Statement对象
* @param con Connection对象
*/
public static void  closeJDBC(ResultSet rs,Statement st,Connection con){
if(rs!=null){
try {
rs.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if(st!=null){
try {
st.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
if(con!=null){
try {
con.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
/**
* 用于获取指定表明的列对应JAVA中的数据类型。
* @param tablename 指定的表名
* @return 列数据类型的数组
*/
public Class[] getTypeOfJava(String tablename){
Connection con=DBHelper.getConnection();
if(con==null){
return null;
}
Statement st=null;
ResultSet rs=null;
Class[] types=null;
try {
st=con.createStatement();
rs=st.executeQuery("select * from "+tablename);
int count=rs.getMetaData().getColumnCount();
types=new Class[count];
for (int i = 0; i < types.length; i++) {
types[i]=Class.forName(rs.getMetaData().getColumnClassName(i+1));
}
return types;

} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}finally{
DBHelper.closeJDBC(rs, st, con);
}
return null;

}
}

七、struts.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1//EN"
"http://struts.apache.org/dtds/struts-2.1.dtd">

<struts>
<include file="sys.xml"></include>
<package name="app" extends="sys" namespace="/sysjsp">
<action name="login" class="com.action.LoginAction" >
</action>
<action name="logout" class="com.action.LoginOutAction">
</action>

</package>

</struts>

 

八、sys.xml（全局结果配置）

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.1//EN"
"http://struts.apache.org/dtds/struts-2.1.dtd">

<struts>

<package name="sys" extends="struts-default" namespace="" abstract="true">
<global-results>
<result name="success">/welcome.jsp</result>
<result name="unsuccess">/index.jsp</result>
</global-results>
</package>

</struts>

 

九、index.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 '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">
-->
</head>
<% request.setCharacterEncoding("utf-8"); %>
<body>
<form action="sysjsp/login" method="post">
用户名：<input type="text" name="user.logname"><br>
密    码：<input type="text" name="user.keyword"><br/>
<input type="submit" value="登录">
</form>
</body>
</html>

十、welcome.jsp

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%
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 'b.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>
您好：${user.logname }，欢迎登录;

<br/>
<br/>
<br/>
<c:set var="map" value="${applicationScope.useronline}" scope="page"></c:set>
<c:forEach items="${pageScope.map}" var="user">
用户：${user.key.logname }在线，session编号为:${user.value.id }
<a href="sysjsp/logout?sessionid=${user.value.id }">强制下线</a>
<hr/>
</c:forEach>

</body>
</html>

简单的实现用户不能重复登录，强制下线的功能，例子中肯定有很多bug，很多细节也没有考虑。刚学的struts大家多多指教。