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我是一个从C#转java的初学者，我在做SSH框架的时候遇到个分页查询的问题。具体算是数据库查询数据后存放在list return回页面，页面接收后是空白的· package com.wh.actions;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import javax.servlet.http.HttpSession;
import org.apache.struts2.ServletActionContext;
import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionSupport;
import com.wh.beans.Productlist;
import com.wh.service.ProductService;
import com.wh.util.Pager;
@SuppressWarnings("serial")
public class Product_listAction extends ActionSupport {
private String Msg;
private List resultList=new ArrayList();//返回结果集
public List getResultList() {
return resultList;
}
public void setResultList(List resultList) {
this.resultList = resultList;
}
public String getMsg() {
return Msg;
}
public void setMsg(String msg) {
Msg = msg;
}
private String product_id;
private String product_name;
private String product_type;
private String Suppliername;
private Integer currentPage=1;
public Integer getCurrentPage() {
return currentPage;
}
public void setCurrentPage(Integer currentPage) {
this.currentPage = currentPage;
}
List<Productlist> prolist = new ArrayList(); ;
private ProductService proService;
private Productlist pro;
public String getProduct_id() {
return product_id;
}
public void setProduct_id(String product_id) {
this.product_id = product_id;
}
public String getProduct_name() {
return product_name;
}
public void setProduct_name(String product_name) {
this.product_name = product_name;
}
public String getProduct_type() {
return product_type;
}
public void setProduct_type(String product_type) {
this.product_type = product_type;
}
public String getSuppliername() {
return Suppliername;
}
public void setSuppliername(String suppliername) {
Suppliername = suppliername;
}
public List<Productlist> getProlist() {
return prolist;
}
public void setProlist(List<Productlist> prolist) {
this.prolist = prolist;
}
public ProductService getProService() {
return proService;
}
public void setProService(ProductService proService) {
this.proService = proService;
}
public Productlist getPro() {
return pro;
}
public void setPro(Productlist pro) {
this.pro = pro;
}
/**
分页
*/
@SuppressWarnings("unchecked")
public String PageList() throws Exception{
int totalSize = proService.GettotalSize(product_id, product_name, product_type, Suppliername);
Pager pager = new Pager(currentPage,totalSize);
prolist =proService.GetProduct_list2(product_id, product_name, product_type, Suppliername,currentPage, pager.getPageSize());
Map request = (Map)ActionContext.getContext().get("request");
//Map session = ActionContext.getContext().getSession();
request.put("pager",pager);
return SUCCESS;
}
}
dao： @SuppressWarnings("unchecked")
public List<Productlist> GetProduct_list2(String product_id,String product_name,String product_type,String supplier,int currentPage,int pageSize){
String sql ="select ProductID as Product_id ,ProductName as Product_name,SupplierID as Suppliername, ";
sql+=" SmallClass as Product_type,price as Product_pice,LargeClass as Reamk";
sql+=" from productmaster";
sql+=" where 1=1";
if(!(isInvalid(product_id)))
{
sql+=" and ProductID="""+product_id+"""";
}
if(!(isInvalid(product_name)))
{
sql+=" and ProductName="""+product_name+"""";
}
if(!(isInvalid(product_type)))
{
sql+=" and SmallClass="""+product_type+"""";
}
if(!(isInvalid(supplier)))
{
sql+=" and SupplierID="""+supplier+"""";
}
sql+=" order by ProductID";
Session session = getsession();
Query query=session.createSQLQuery(sql);
int startRow = (currentPage - 1) * pageSize;
query.setFirstResult(startRow);
query.setMaxResults(pageSize);
List<Productlist> list = query.list();
session.close();
return list;
}
bean： package com.wh.beans;
/**
* Book generated by MyEclipse - Hibernate Tools
*/
public class Productlist {
private String Product_id;
private String Product_name;
private String Product_type;
private String Suppliername;
private double Product_pice;
private String Reamk;
public String getProduct_id() {
return Product_id;
}
public void setProduct_id(String product_id) {
Product_id = product_id;
}
public String getProduct_name() {
return Product_name;
}
public void setProduct_name(String product_name) {
Product_name = product_name;
}
public String getProduct_type() {
return Product_type;
}
public void setProduct_type(String product_type) {
Product_type = product_type;
}
public String getSuppliername() {
return Suppliername;
}
public void setSuppliername(String suppliername) {
Suppliername = suppliername;
}
public double getProduct_pice() {
return Product_pice;
}
public void setProduct_pice(double product_pice) {
Product_pice = product_pice;
}
public String getReamk() {
return Reamk;
}
public void setReamk(String reamk) {
Reamk = reamk;
}
}
jsp页面： <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<%@ page import="com.wh.beans.Productlist" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>商品查询</title>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<link href="Style/Style.css" rel="stylesheet" type="text/css" />
<script type="text/javascript">
function btn_Submit(){
var myform = document.forms["form_pro"];
myform.action="roduct_List.action";
myform.method="post";
myform.submit();
}
</script>
</head>
<body>
<center>
<table width="100%" height="100%" border="0" cellspacing="0" cellpadding="0">
<tr>
<td>
<%@ include file="Top.jsp"%>
</td>
</tr>
<tr>
<td height="500" align="center" valign="top">
<table width="900" border="0" cellspacing="0" cellpadding="0">
<tr>
<td width="191" height="500" align="center" valign="top" background="Images/leftbg.jpg">
<%@ include file="Left.jsp"%>
</td>
<td width="709" align="center" valign="top" bgcolor="#F6F9FE">
<form name="form_pro">
<table width="709" border="1" cellspacing="0" cellpadding="0">
<tr>
<td colspan="6" height="30" width="100%" background="Images/mainMenuBg.jpg" style="padding-left:25px;">商品查询</td>
</tr>
<tr>
<td class="leftsize">
商品编码：
</td>
<td class="rightsize" >
<input type="text" name="product_id" value="${product_id}" />
</td>
<td class="leftsize">
商品名称：
</td>
<td class="rightsize">
<input type="text" name="product_name" value="${product_name}" />
</td>
<td class="leftsize">
商品分类：
</td>
<td class="rightsize">
<input type="text" name="product_type" value="${product_type}"/>
</td>
</tr>
<tr>
<td class="leftsize">
供应商：
</td>
<td class="rightsize">
<input type="text" name="Suppliername" value="${Suppliername}"/>
</td>
<td colspan="4" align="right">
<input type="button" name="btn_Submint" value="查询" OnClick="btn_Submit()">
</td>
</tr>
</table>
</form>
<s:set name="pager" value="#request.pager"/>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
<tr align="center" class="t1">
<td height="25" bgcolor="#D5E4F4"><strong>商品编号</strong></td>
<td bgcolor="#D5E4F4"><strong>商品名称</strong></td>
<td bgcolor="#D5E4F4"><strong>商品分类</strong></td>
<td bgcolor="#D5E4F4"><strong>供应商名称</strong></td>
<td bgcolor="#D5E4F4"><strong>商品价格</strong></td>
<td bgcolor="#D5E4F4"><strong>备注</strong></td>
</tr>
<s:iterator value="prolist">
<tr>
<td height="25" align="center"><s:property value="Product_id"/></td>
<td><s:property value="Product_name"/></td>
<td><s:property value="Product_type"/></td>
<td><s:property value="Suppliername"/></td>
<td><s:property value="Product_pice"/></td>
<td><s:property value="Reamk"/></td>
</tr>
</s:iterator>
</table>
<table>
<s:if test="#pager.hasFirst">
<a href="page_product.action?currentPage=1">首页</a>
</s:if>
<s:if test="#pager.hasPrevious">
<a href="page_product.action?currentPage=<s:property value="#pager.currentPage-1"/>">上一页</a>
</s:if>
<s:if test="#pager.hasNext">
<a href="page_product.action?currentPage=<s:property value="#pager.currentPage+1"/>">下一页</a>
</s:if>
<s:if test="#pager.hasLast">
<a href="page_product.action?currentPage=<s:property value="#pager.totalPage"/>">尾页</a>
</s:if>
<br>
当前第<s:property value="#pager.currentPage"/>页,总共<s:property value="#pager.totalPage"/>页
</table>
</td>
</tr>
</table>
</td>
</tr>
<tr>
<td height="35" background="Images/bootBg.jpg"> </td>
</tr>
</table>
</center>
</body>
</html>
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 25分 |
你现在Action遍历打印一下prolist，看看你数据都拿到了没~~
还有把prolist定义成public的 感觉你封装的不太对，分页数据的List没有封装到Pager对象中去吗？ |
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楼上正解！
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我试着遍历了下 出了个问题 for(int i = 0;i<prolist.size();i++){
System.out.print(prolist.get(i).getProduct_id()+",");
System.out.print(prolist.get(i).getProduct_name()+",");
System.out.print(prolist.get(i).getProduct_pice()+",");
System.out.print(prolist.get(i).getProduct_type()+",");
System.out.print(prolist.get(i).getSuppliername()+",");
System.out.print(prolist.get(i).getReamk()+",");
System.out.println("--------------------------------");
}
[Ljava.lang.Object; cannot be cast to com.wh.beans.Productlist pager里面封装的是 当前页数，总页数，合上一页下一页这些信息 |
25分 |
prolist里面不是放的ProductList对象实例吗？ 如果对象数组里面东西没问题，页面用 |
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我研究出来了，谢谢你 对于我一个半道进java的帮助！
List<Object[]> list = query.list();
session.close();
List<Productlist> prolist = new ArrayList<Productlist>();
for(int i =0;i<list.size();i++){
Object[] obs=list.get(i);
Productlist po = new Productlist();
po.setProduct_id((String)obs[0]);
po.setProduct_name((String)obs[1]);
po.setSuppliername((String)obs[2]);
po.setProduct_type((String)obs[3]);
po.setProduct_pice(Double.parseDouble(obs[4].toString()));
po.setReamk((String)obs[5]);
prolist.add(po);
}
return prolist;
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我研究出来了，谢谢你 对于我一个半道进java的帮助！
List<Object[]> list = query.list();
session.close();
List<Productlist> prolist = new ArrayList<Productlist>();
for(int i =0;i<list.size();i++){
Object[] obs=list.get(i);
Productlist po = new Productlist();
po.setProduct_id((String)obs[0]);
po.setProduct_name((String)obs[1]);
po.setSuppliername((String)obs[2]);
po.setProduct_type((String)obs[3]);
po.setProduct_pice(Double.parseDouble(obs[4].toString()));
po.setReamk((String)obs[5]);
prolist.add(po);
}
return prolist;
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