lunzi

这是我用spring+hibernate+struts开发的项目的第一个功能action，其中这chkName方法是检测注册的用户在数据库中是否有重名．
//Created by MyEclipse Struts
// XSL source (default): platform:/plugin/com.genuitec.eclipse.cross.easystruts.eclipse_4.1.1/xslt/JavaClass.xsl

package news.action;

import news.*;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import news.form.UserForm;

import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.actions.DispatchAction;

/** 
 * MyEclipse Struts
 * Creation date: 06-09-2006
 * 
 * XDoclet definition:
 * @struts.action path="/user" name="userForm" input="/form/errors.jsp" parameter="method" scope="request" validate="true"
 */
public class UserAction extends DispatchAction {

	// --------------------------------------------------------- Instance Variables

	// --------------------------------------------------------- Methods
  private	UserDAO userDAO;
 static{
	ApplicationContextFactory.init("/news/applicationContext.xml");
	
   }
public ActionForward chkName(ActionMapping mapping, 
            ActionForm form, 
            HttpServletRequest request, 
            HttpServletResponse response)throws Exception { 

   UserForm userform = (UserForm) form;         
   String name = userform.getName();
   

   userDAO = (UserDAO) ApplicationContextFactory.getApplicationContext().getBean("userDAO");

   boolean go=userDAO.chkName(name);
     if(go)
     {
	
    	 return (mapping.findForward("chkNameFailed"));	
	
     }
         return (mapping.findForward("chkNameOk"));	
	   		  


  }	

}

下边是封装好数据库的DAO文件的实现类UserDAOImpl.java
package news;

import java.util.List;
//import org.apache.commons.logging.Log;
import org.springframework.orm.hibernate.support.HibernateDaoSupport;


public class UserDAOImpl extends HibernateDaoSupport implements UserDAO{

	public List getUsers(){
		return getHibernateTemplate().findByNamedQuery("AllUsers");
	}

	public User findUserByName(String name) {
		return (User) getHibernateTemplate().find("from User u where u.name=?",name).get(0);
	}

    public void addUser(User user){
                getHibernateTemplate().save(user);
    }
    
  
    public User getUserById(Integer id) {
        return (User) getHibernateTemplate().load(User.class, id);
    }

    public User chkLogin(String name,String password){
    	return (User) getHibernateTemplate().find("from User u where u.name='"+name+"' and u.password='"+password+"'").get(0);
    }
   
    public User getUser(String username) throws DAOException {
        User user = null;

        // TODO: Fix this hack
        long userId = 0;
        try {
            userId = Long.parseLong(username);
        } catch (NumberFormatException npe) {
            // ignore - not an id, really is a username
        }
        
        if (userId != 0) {
            return (User) getHibernateTemplate().get(User.class, new Long(userId));
        }
        
        List users =
            getHibernateTemplate().find("from User u where u.username=?",
                                        username);

        if ((users != null) && (users.size() > 0)) {
            user = (User) users.get(0);
        }

        if (user == null) {
           // log.warn("uh oh, user not found...");
            throw new DAOException("User '" + username +
                                   "' not found in database!");
        }

        return user;
    }
    
    public void removeUser (String name) {
		User user = findUserByName(name);
		this.getHibernateTemplate().delete(user);
	}
    
    public void updateUser(User user) {
    	
        getHibernateTemplate().update(user);
     
    }
    
    private static String hql = "from User u where u.name=? and password=?";

	public boolean isValidUser(String username, String password) {

		String[] userlist=new String[2];
		userlist[0]=username;
		userlist[1]=password;
//		List userList = this.getHibernateTemplate().find(hql, (Object)username);
		List userList = this.getHibernateTemplate().find(hql,userlist);

		if (userList.size() > 0) {

			return true;

		}

		return false;

	}
	
	private static String hql2="from User u where u.name=?";
	
	public boolean chkName(String name){
		List userList2=this.getHibernateTemplate().find(hql2,name);
		
		if(userList2.size()>0){
			
			return true;
		}
		
		    return false;
	}

}
调用的jsp文件：
<%@ page language="java"%>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>

<html> 
	<head>
		<title>JSP for userForm form</title>
	</head>
	<body>
		<html:form action="/user.do?method=chkName">
			
			<bean:message key="user.name"/>
			<html:text property="name"/><html:errors property="name"/><br/>
		
			<html:submit/><html:cancel/>
		</html:form> 	 	
	</body>
</html>