谷歌应用引擎用户注册系统

Question

我正在谷歌应用引擎中创建一个用户注册系统，到目前为止，我可以开发应用程序的注册端。但是我无法登录并创建 HttpSession。

在这里，我创建了登录名.jsp和两个文本框来输入电子邮件和密码。

然后我创建了Bean类和DAO类，如下所示。 Package com.myfirstguide.beans;

import javax.servlet.http.HttpSession;
import com.google.appengine.api.datastore.DatastoreService;
import com.google.appengine.api.datastore.DatastoreServiceFactory;
import com.google.appengine.api.datastore.Entity;
import com.google.appengine.api.datastore.PreparedQuery;
import com.google.appengine.api.datastore.Query;
public class UserDAO {
public static UserBean login(UserBean bean){
    String email = bean.getEmail();
    String password = bean.getPassword();
    try{
        DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
        Query q = new Query("Account");
        q.addFilter("email", Query.FilterOperator.EQUAL, email);
        q.addFilter("password", Query.FilterOperator.EQUAL, password);
        PreparedQuery pq = datastore.prepare(q);
        Entity result = pq.asSingleEntity();
        if(result != null){
            bean.setValid(true);
        }
        //return bean;
    }catch(Exception e){
    }
    return bean;
}
}

这是豆类。

package com.myfirstguide.beans;
public class UserBean {
private String username; 
private String password; 
private String firstName;
private String lastName; 
private String email;
public boolean valid; 
public String getFirstName() {
    return firstName; 
} 
public void setFirstName(String newFirstName) { 
    firstName = newFirstName; 
} 
public void setEmail(String semail){
    email = semail;
}
public String getEmail(){
    return email;
}
public String getLastName() {
    return lastName; 
} 
public void setLastName(String newLastName) { 
    lastName = newLastName; 
} 
public String getPassword() { 
    return password;
} 
public void setPassword(String newPassword) { 
    password = newPassword;
} 
public String getUsername() {
    return username; 
} 
public void setUserName(String newUsername) {
    username = newUsername; 
} 
public boolean isValid() {
    return valid;
} 
public void setValid(boolean newValid) {
    valid = newValid;
} 
 }

这是 Servlet。

package com.myfirstguide.users;
import java.io.IOException;
import javax.servlet.ServletException;
 import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import com.myfirstguide.beans.UserBean;
import com.myfirstguide.beans.UserDAO;
 public class SignIn extends HttpServlet{
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException {
    String email = req.getParameter("email");
    String password = req.getParameter("password");
    try{
        UserBean ubean = new UserBean();
        ubean.setEmail(email);
        ubean.setPassword(password);
        ubean = UserDAO.login(ubean);
        if(ubean.isValid()){
              HttpSession session = req.getSession(true);       
              session.setAttribute("currentSessionUser",ubean); 
              resp.sendRedirect("index.jsp?session=" + ubean.getFirstName()); //logged-in page      
        }
    }catch(Throwable e){
        System.out.println(e);
    }
}
 }

而且我不知道JPA。如果有更好的方法，请告诉我。

谢谢！

Answer 1

您是否启用了会话？

https://developers.google.com/appengine/docs/java/config/appconfig#Enabling_Sessions