休眠打印會話對象數據列表中的數據

我讓錯誤的HQL嘗試訪問另一個表中的列。抱歉。 此問題已解決。 我有Object類型的ArrayList。從會話中提取。它存在。我檢查。但我甚至可以從會話中獲取信息。將其更改爲ArrayList。休眠打印會話對象數據列表中的數據

我的目標是打印結果。我選擇了一些sql列，我只是想輸出它們。當然這是對象。我沒有錯誤，這是問題。只有我的類型產品的現有數組列表對象。

ArrayList <prod> goodlist = (ArrayList <prod>) session.getAttribute("goodlist_s"); 


for (prod glst : goodlist) { 
       %> 
       <tr> 
        <td><%//=out.println(u.getname())%></td> 
        <td><%=glst.getcatid()%></td>}

我嘗試將其轉換爲字符串ArrayList。

這是我的功能

@SuppressWarnings("unchecked") 
public static ArrayList<prod> getListOfProds(String catname,String name,Integer pricel, Integer priceh){ 
    ArrayList<prod> list = new ArrayList<prod>(); 
    Session session = HibernateUtil.openSession(); 
    Transaction tx = null;   
    try { 
     tx = session.getTransaction(); 
     tx.begin(); 
     Query query = session.createQuery("from prod where catname=?"); 
     query.setString(0, catname); 
     //query.setInteger(1, pricel); 
     //query.setInteger(2, priceh); 
     list = (ArrayList<prod>) query.list(); 

     tx.commit(); 
    } catch (Exception e) { 
     if (tx != null) { 
      tx.rollback(); 
     } 
     e.printStackTrace(); 
    } finally { 
     session.close(); 
    } 
    return list; 
}

BTW，我會發來的所有代碼 的index.jsp

<%@page import="java.util.List"%> 
<%@page import="service.IndexService"%> 
<%@page import="java.util.Date"%> 

<%@page import="goods.prod"%> 
<%@page import="goods.cat"%> 
<%@page import ="java.util.ArrayList"%> 
<%@page import ="java.util.List"%> 

<%@page contentType="text/html" pageEncoding="UTF-8"%> 


<!DOCTYPE html> 
<html> 
<head> 
    <meta http-equiv="Content-Type" content="text/html; charprods=UTF-8"> 
    <link rel="stylesheet" type="text/css" href="css/style.css"/> 
    <title>Result Page</title> 
</head> 

</head> 
<body> 
<form action="IndexServlet" method="POST"> 


<table align="center" cellpadding = "10"> 
<tr> 
<td>Category</td> 
<td><input type="text" name="catname" maxlength="30"/> 
(max 30 characters a-z and A-Z) 
</td> 
</tr> 
<tr> 
<td>Category id</td> 
<td><input type="number" name="catid" maxlength="30"/> 
(max 30 characters a-z and A-Z) 
</td> 
</tr> 
<tr> 
<td>Naimenovanie</td> 
<td><input type="text" name="name" maxlength="30"/> 
(max 30 characters a-z and A-Z) 
</td> 
</tr> 

<tr> 
<td>Price low</td> 
<td><input type="number" name="pricel" maxlength="30"/> 
(max 30 characters a-z and A-Z) 
</td> 
</tr> 

<tr> 
<td>Price high</td> 
<td><input type="number" name="priceh" maxlength="100" /></td> 
</tr> 

<tr> 
<td colspan="2" align="center"> 
<input type="submit" value="Submit"> 
<input type="reset" value="Reset"> 
</td> 
</tr> 
</table> 


prodsAttribute 
<% 
    prod prod = (prod) session.getAttribute("prod"); 
%>  
    <% 
    ArrayList <prod> goodlist = (ArrayList <prod>) session.getAttribute("goodlist_s"); 


%> 

<b>You have<% if (null == prod) out.println("No text entered.");%></b>  
    <b>You have<% if (null == goodlist) out.println("goodlist does NOT exists.");%></b> 
    <b>You have<% if (null != goodlist) { 
     ArrayList<String> jlistTitles = new ArrayList<String>((ArrayList<String>) session.getAttribute("goodlist_s")); 
     if (null == jlistTitles) out.println("convertedStringlist does NOT exists."); 
     if (null != jlistTitles) out.println("convertedStringlist exists. How can I use it?"); 
     for(int i = 0; i < goodlist.size(); i++) { 
      System.out.println(goodlist.get(i).getprice()); 
      //print object type 
      } 

     out.println("goodlist exists. How can I use it?");}%></b> 

<br> 
    <b><%if (null!=prod) out.println(prod.getid()+ " "+prod.getname()+ " "+prod.getprice());%></b>  
<br/> 
       <% 
       if (null!=goodlist) { 
        for (prod glst : goodlist) { 
       %> 
       <tr> 
        <td><%//=out.println(u.getname())%></td> 
        <td><%=glst.getcatid()%></td> 
        <td><%=glst.getprice()%></td>     
        <td><%="hh"%></td> 
       </tr> 
       <%}}%> 



</form> 
</body> 
</html>

Indexservlet.java

package servlet; 

import java.io.IOException; 
import java.util.ArrayList; 
import java.util.List; 

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

import goods.prod; 
import service.IndexService; 

public class IndexServlet extends HttpServlet { 

    private static final long serialVersionUID = -8670416133536111566L; 

    public void doPost(HttpServletRequest request, HttpServletResponse response) 
      throws ServletException, IOException { 
    response.setContentType("text/html;charprods=UTF-8"); 
    //Long id = Long.parseLong(request.getParameter("id")); 
    String name = request.getParameter("name"); 
    String catname = request.getParameter("catname"); 
    Integer pricel = Integer.parseInt(request.getParameter("pricel")); 
    Integer priceh = Integer.parseInt(request.getParameter("priceh")); 


    prod dot = IndexService.getprodbyparam(catname,name,pricel,priceh); 
    List<prod> goodlist = IndexService.getListOfProds(catname,name,pricel,priceh); 

    request.getSession().setAttribute("goodlist_s", goodlist); 
    request.getSession().setAttribute("prod", dot);   
    response.sendRedirect("index.jsp"); 

} 

}

與功能

package service; 

import java.sql.DriverManager; 
import java.util.ArrayList; 
import java.util.List; 

import org.hibernate.Criteria; 
import org.hibernate.Query; 
import org.hibernate.Session; 
import org.hibernate.Transaction; 



import HibernateUtil.HibernateUtil; 
import goods.prod; 

public class IndexService { 

     public static prod getprodbyparam(String catname,String name,Integer pricel, Integer priceh) { 
      Session session = HibernateUtil.openSession(); 
      Transaction tx = null; 
      prod prod = null; 
      try { 
       tx = session.getTransaction(); 
       tx.begin(); 
       //Query query = session.createQuery("select prod.id from prod as prod inner join cat.id as id where name=?"); 
       Query query = session.createQuery("from prod where name=? and price between ? and ?"); 
       query.setString(0, name); 
       query.setInteger(1, pricel); 
       query.setInteger(2, priceh); 
       //query.prodsInteger(3, catid); 
       prod = (prod)query.uniqueResult(); 
       tx.commit(); 
      } catch (Exception e) { 
       if (tx != null) { 
        tx.rollback(); 
       } 
       e.printStackTrace(); 
      } finally { 
       session.close(); 
      } 
      return prod; 
     } 




    @SuppressWarnings("unchecked") 
    public static ArrayList<prod> getListOfProds(String catname,String name,Integer pricel, Integer priceh){ 
     ArrayList<prod> list = new ArrayList<prod>(); 
     Session session = HibernateUtil.openSession(); 
     Transaction tx = null;   
     try { 
      tx = session.getTransaction(); 
      tx.begin(); 
      Query query = session.createQuery("from prod where catname=?"); 
      query.setString(0, catname); 
      //query.setInteger(1, pricel); 
      //query.setInteger(2, priceh); 
      list = (ArrayList<prod>) query.list(); 

      tx.commit(); 
     } catch (Exception e) { 
      if (tx != null) { 
       tx.rollback(); 
      } 
      e.printStackTrace(); 
     } finally { 
      session.close(); 
     } 
     return list; 
    } 


    }

督促與干將

package goods; 

import javax.persistence.Column; 
import javax.persistence.Entity; 
import javax.persistence.FetchType; 
import javax.persistence.GeneratedValue; 
import javax.persistence.Id; 
import javax.persistence.JoinColumn; 
import javax.persistence.JoinColumns; 
import javax.persistence.ManyToOne; 
import javax.persistence.OneToMany; 
import javax.persistence.OneToOne; 
import javax.persistence.Table; 

import java.io.Serializable; 


@Entity 
@Table(name = "prod") 

public class prod implements Serializable { 

    @Id @GeneratedValue 
    @Column(name = "id") 
    private Long id; 

    private Integer catid; 

    private String name; 
    private Integer price; 


    public prod() { 
    } 

    public prod(Long id, Integer catid, String name, Integer price) { 
     this.id = id; 
     this.catid = catid; 
     this.name = name ; 
     this.price = price; 
    } 

    public Long getid() { 
     return id; 
    } 

    public void setid(Long id) { 
     this.id = id; 
    } 

    public Integer getcatid() { 
     return catid; 
    } 
    public void setcatid(Integer catid) { 
     this.catid = catid; 
    } 

    public String getname() { 
     return name; 
    }  
    public void setname(String name) { 
     this.name = name; 
    } 

    public Integer getprice() { 
     return price; 
    } 
    public void setprice(Integer price) { 
     this.price = price; 
    } 

    }

的web.xml Indexservice

<?xml version="1.0" encoding="UTF-8"?> 
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5"> 
    <display-name>Improve</display-name> 
    <servlet> 
     <servlet-name>IndexServlet</servlet-name> 
     <servlet-class>servlet.IndexServlet</servlet-class> 
    </servlet> 
    <servlet-mapping> 
     <servlet-name>IndexServlet</servlet-name> 
     <url-pattern>/IndexServlet</url-pattern> 
    </servlet-mapping> 

    <welcome-file-list> 
     <welcome-file>index.jsp</welcome-file> 
    </welcome-file-list> 
</web-app>

來源

2016-04-13 ifooi

你是否想要這樣做的第一次？ – Acewin

您是否嘗試了request.setAttribute而不是將對象設置爲會話 – Acewin

request.getSession（）。setAttribute（「goodlist_s」，goodlist）; \t request.getSession（）。setAttribute（「prod」，dot）;這是在我的代碼。當然，我會按要求做。 – ifooi

能否請您嘗試貝盧w代碼，看看它是否工作

ArrayList<String> goodlist_s= (ArrayList<String>)session.getAttribute("goodlist_s"); 


<% 
for(int i = 0; i < goodlist_s.size(); i++) 
{ 
String myString = (String) goodlist_s.get(i); 
} 
%>

來源

2016-04-13 17:35:05 LearningPhase

@ifooi有幫助嗎？ – LearningPhase

if（null！= goodlist_s）out.println（「goodlist_s does exists。」）;它的作品，它給我輸出 – ifooi

你可以嘗試打印值現在 – LearningPhase

休眠打印會話對象數據列表中的數據

回答

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