jsf會話或配置問題

這是一個來自mkyong.com的示例，我稍加修改。我添加了一個輸入文本和命令來發送下一個在mysql中進行分頁的偏移量。如預期的那樣，第一頁自動加載偏移量爲0。如果我在輸入文本中鍵入5，它實際上是有效的，下一頁顯示下面的5條記錄。但是，如果我現在輸入10，它將停止工作，並且頁面會一直嘗試加載。我等了5分鐘，什麼也沒有。另一個重試，0第一次加載輸入15只是爲了測試，它的工作。但是在第一次使用commandButton之後試圖使它工作，它只是停滯不前。jsf會話或配置問題

在url中顯示當前的sessionid。這是會話問題還是配置問題？

我是jsf的新手，並且正在努力學習如何通過正確發送請求來使頁面顯示某些內容。我從oracles站點上的javaeetutorial6，guessnumber/duke示例直接獲得了inputText和commandButton的想法。

package model; 

    //import java.util.Date; 

    public class Customer{ 

     public String petid; 
     public String petname; 
      public String tmpvar; 
     private String offset; 
     //public String address; 
     //public Date created_date; 
      //private String searchText; 
      //public String getSearchText() { return searchText; } 
      //public void setSearchText(String s) { searchText = s; } 
     public String getpetid() { 
      return petid; 
     } 
     public void setpetid(String petid) { 
      this.petid = petid; 
     } 
     public String getpetname() { 
      return petname; 
     } 
     public void setpetname(String petname) { 
      this.petname = petname; 
     } 
     /*public String getAddress() { 
      return address; 
     } 
     public void setAddress(String address) { 
      this.address = address; 
     } 
     public Date getCreated_date() { 
      return created_date; 
     } 
     public void setCreated_date(Date created_date) { 
      this.created_date = created_date; 
     }*/ 
      public String gettmpvar() { 
      return tmpvar; 
     } 
     public void settmpvar(String tmpvar) { 
      this.tmpvar = tmpvar; 
     } 



    } 

package cust; 

import java.io.Serializable; 
import java.sql.Connection; 
import java.sql.PreparedStatement; 
import java.sql.ResultSet; 
import java.sql.SQLException; 
import java.util.ArrayList; 
import java.util.List; 

import javax.annotation.Resource; 
import javax.faces.bean.ManagedBean; 
import javax.faces.bean.SessionScoped; 
import javax.faces.context.FacesContext; 
import javax.naming.Context; 
import javax.naming.InitialContext; 
import javax.naming.NamingException; 
import javax.servlet.http.HttpServletRequest; 
import javax.sql.DataSource; 

import model.Customer; 

@ManagedBean(name="Customer") 
//@SessionScoped 

public class CustomerBean implements Serializable{ 
int userNumber; 
String offset; 
//String SearchText; 
    //resource injection 
    @Resource(name="jdbc/petback2") 
    private DataSource ds; 

    //if resource injection is not support, you still can get it manually. 
    /*public CustomerBean(){ 
     try { 
      Context ctx = new InitialContext(); 
      ds = (DataSource)ctx.lookup("jdbc/petback2"); 
     } catch (NamingException e) { 
     } 

    }*/ 

    //connect to DB and get customer list 

     public String searchText; 
    //private String offset; 
     public String getSearchText() { return searchText; } 
     public void setSearchText(String s) { searchText = s; } 


     public List<Customer> getCustomerList() throws SQLException{ 
int rowsperpage = 5; 
//String offset; 
//HttpServletRequest request = (HttpServletRequest) FacesContext.getCurrentInstance().getExternalContext().getRequest(); 
//offset = request.getParameter("offset"); 
//if ( offset == null ? "" == null : offset.equals("")) 
//if (offset null ? "" == null : offset.equals("0") 
//{ 
//getoffset(); 
//String voffset; 
//voffset = offset; 

if (offset == null) 
    { 
    offset = "0"; 
    } 
System.out.println(offset); 
//} 
//int pageno = 0; 
//int offset = 5; 

//offset = "5"; 
//offset = CustomerBean.this.searchText; 
//offset = getResponse(); 
     if(ds==null) 
      throw new SQLException("Can't get data source"); 

     //get database connection 
     Connection con = ds.getConnection(); 

     if(con==null) 
      throw new SQLException("Can't get database connection"); 

     PreparedStatement ps 
      = con.prepareStatement(
       "select petid, petname from pets LIMIT "+ offset + ", " + rowsperpage); 
       //"select petid, petname from pets LIMIT "+ offset + ", " + rowsperpage); 
     //get customer data from database 
     ResultSet result = ps.executeQuery(); 

     List<Customer> list = new ArrayList<Customer>(); 
       //Customer cust2 = new Customer(); 
     while(result.next()){ 
      Customer cust2 = new Customer(); 

      cust2.setpetid(result.getString("petid")); 
      cust2.setpetname(result.getString("petname")); 
      //cust2.setAddress(result.getString("address")); 
      //cust2.setCreated_date(result.getDate("created_date")); 

      //store all data into a List 
      list.add(cust2); 
     } 
       //List<Customer> list1 = new ArrayList<Customer>(); 
       //Customer cust3 = new Customer(); 
       Customer cust2 = new Customer(); 
       cust2.settmpvar("hello"); 
       list.add(cust2); 
     return list; 




    } 

    public void setoffset(String user_number) { 
     this.offset = user_number; 
     System.out.println(offset); 
    } 

    public String getoffset() { 
     return offset; 
    } 






}

newjsf.html

<?xml version="1.0" encoding="UTF-8"?> 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" 
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml" 
     xmlns:h="http://java.sun.com/jsf/html" 
     xmlns:f="http://java.sun.com/jsf/core"> 


    <h:head> 
     <h:outputStylesheet library="css" name="table-style.css" /> 
     <script type="text/javascript" src="include/jquery.js"></script> 
<script type="text/javascript" src="include/myjq.js"></script> 



    </h:head> 

    <h:body> 
     <h:form> 



     <h:dataTable id="myTable" value="#{Customer.customerList}" var="c" border="1" 
       styleClass="order-table" 
       headerClass="order-table-header" 
       rowClasses="order-table-odd-row,order-table-even-row" 
      > 

      <h:column> 
       <f:facet name="header"> 
        petid 
       </f:facet> 
        #{c.petid} 
      </h:column> 

      <h:column> 
       <f:facet name="header"> 
        petname 
       </f:facet> 
        #{c.petname} 
      </h:column> 



     </h:dataTable> 
      <h:inputText 
        id="userNo" 
        value="#{Customer.offset}"> 

       </h:inputText> 
<h:commandButton id="submit" value="Submit" 
           action="newjsf.xhtml"/> 
     </h:form> 
    </h:body> 

</html>

配置：

<?xml version="1.0" encoding="UTF-8"?> 
<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"> 
    <context-param> 
     <param-name>javax.faces.PROJECT_STAGE</param-name> 
     <param-value>Development</param-value> 
    </context-param> 
    <servlet> 
     <servlet-name>Faces Servlet</servlet-name> 
     <servlet-class>javax.faces.webapp.FacesServlet</servlet-class> 
     <load-on-startup>1</load-on-startup> 
    </servlet> 
    <servlet-mapping> 
     <servlet-name>Faces Servlet</servlet-name> 
     <url-pattern>*.xhtml</url-pattern> 
     <!--<url-pattern>/faces/*</url-pattern> 
     <url-pattern>/faces/*</url-pattern>--> 
    </servlet-mapping> 
    <session-config> 
     <session-timeout> 
      30 
     </session-timeout> 
    </session-config> 
    <welcome-file-list> 
     <welcome-file>faces/newjsf.xhtml</welcome-file> 
    </welcome-file-list> 
</web-app>

來源

2011-07-27 user560131

得到它的工作，改到用戶界面：重複，並用下面的發送得到而不是職位：

<h:outputLink id="link1" value="newui.xhtml?voffset=#{Customer.offset - 5}"> 
    <h:outputText value="prev" /> 
</h:outputLink> 

<h:outputLink id="link2" value="newui.xhtml?voffset=#{Customer.offset + 5}"> 
    <h:outputText value="next" /> 
</h:outputLink>

而在豆：

HttpServletRequest req = (HttpServletRequest)FacesContext.getCurrentInstance().getExternalContext().getRequest(); 
      offset = req.getParameter("voffset"); 
      if (offset == null) { 
       offset = "0"; 
      }

，並

public void setoffset(String voffset) { 
     this.offset = voffset; 
     //System.out.println(offset); 
    } 

    public String getoffset() { 
     return offset; 
    }

我不知道怎麼樣，而是集/獲得作品沒有給它一個電話，可能是自動處理。無論如何，現在分頁工作就像一個冠軍，比數據表更多的控制。

來源

2011-08-01 02:20:46 user560131

也注意到沒有那個懶加載的東西，純粹的限制子句通過mysql，因此完全有效，這可以處理數百萬條記錄，因爲你只加載了很多你放在rowsperpage var。似乎BalusC需要更多的代碼行 – user560131

jsf會話或配置問題

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