実用的な JSP ページング コード

熱心なネチズンは次のように答えました:
str += "Go to7fd8600b4213bccad84950f81a7a6ca3";
すでに試しました、問題ありません

1. 以下はページング

package page.bean; 
import java.util.*; 
public class PageResultSet { 
/** 
* 分页数据 
*/ 
private Collection data = null; 
/** 
* 当前页 
*/ 
private int curPage; 
/** 
* 每页显示的记录数 
*/ 
private int pageSize; 
/** 
* 记录行数 
*/ 
private int rowsCount; 
/** 
* 页数 
*/ 
private int pageCount; 
public PageResultSet(Collection data) { 
this.data = data; 
this.curPage = 1; 
this.pageSize = 10; 
this.rowsCount = data.size(); 
this.pageCount = (int) Math.ceil((double) rowsCount / pageSize); 
} 
public PageResultSet(Collection data, int curPage) { 
this.data = data; 
this.curPage = curPage; 
this.pageSize = 10; 
this.rowsCount = data.size(); 
this.pageCount = (int) Math.ceil((double) rowsCount / pageSize); 
} 
public PageResultSet(Collection data, int curPage, int pageSize) { 
this.data = data; 
this.curPage = curPage; 
this.pageSize = pageSize; 
this.rowsCount = data.size(); 
this.pageCount = (int) Math.ceil((double) rowsCount / pageSize); 
} 
/** 
* getCurPage:返回当前的页数 
* 
* @return int 
*/ 
public int getCurPage() { 
return curPage; 
} 
/** 
* getPageSize：返回分页大小 
* 
* @return int 
*/ 
public int getPageSize() { 
return pageSize; 
} 
/** 
* getRowsCount：返回总记录行数 
* 
* @return int 
*/ 
public int getRowsCount() { 
return rowsCount; 
} 
/** 
* getPageCount：返回总页数 
* 
* @return int 
*/ 
public int getPageCount() { 
return pageCount; 
} 
/** 
* 第一页 
* 
* @return int 
*/ 
public int first() { 
return 1; 
} 
/** 
* 最后一页 
* 
* @return int 
*/ 
public int last() { 
return pageCount; 
} 
/** 
* 上一页 
* 
* @return int 
*/ 
public int previous() { 
return (curPage - 1 < 1) ? 1 : curPage - 1; 
} 
/** 
* 下一页 
* 
* @return int 
*/ 
public int next() { 
return (curPage + 1 > pageCount) ? pageCount : curPage + 1; 
} 
/** 
* 第一页 
* 
* @return boolean 
*/ 
public boolean isFirst() { 
return (curPage == 1) ? true : false; 
} 
/** 
* 最后一页 
* 
* @return boolean 
*/ 
public boolean isLast() { 
return (curPage == pageCount) ? true : false; 
} 
/** * 获取当前页数据 
* 
* @return Collection 
*/ 
public Collection getData() { 
Collection curData = null; 
if (data != null) { 
int start = (curPage - 1) * pageSize; 
int end = 0; 
if (start + pageSize > rowsCount) 
end = rowsCount; 
else 
end = start + pageSize; 
ArrayList arrayCurData = new ArrayList(); 
ArrayList arrayData = null; 
Vector vectorCurData = new Vector(); 
Vector vectorData = null; 
boolean isArray = true; 
if (data instanceof ArrayList) { 
arrayData = (ArrayList) data; 
isArray = true; 
} else if (data instanceof Vector) { 
vectorData = (Vector) data; 
isArray = false; 
} 
for (int i = start; i < end; i++) { 
if (isArray) { 
arrayCurData.add(arrayData.get(i)); 
} else { 
vectorData.add(vectorData.elementAt(i)); 
} 
} 
if (isArray) { 
curData = (Collection) arrayCurData; 
} else { 
curData = (Collection) vectorCurData; 
} 
} 
return curData; 
} 
/** 
* 获取工具条 
* 
* @return String 
*/ 
public String getToolBar(String fileName) { 
String temp = ""; 
if (fileName.indexOf("?") == -1) { 
temp = "?"; 
} else { 
temp = "&"; 
} 
String str = "<form method=&#39;post&#39; name=&#39;frmPage&#39; action=&#39;" + fileName + "&#39;>"; 
str += "<p align=&#39;center&#39;>"; 
if (isFirst()) 
str += "首页 上一页 "; 
else { 
str += "<a href=&#39;" + fileName + temp + "cur_page=1&#39;>首页</a> "; 
str += "<a href=&#39;" + fileName + temp + "cur_page=" + (curPage - 1) + "&#39;>上一页</a> "; 
} 
if (isLast()) 
str += "下一页 尾页 "; 
else { 
str += "<a href=&#39;" + fileName + temp + "cur_page=" + (curPage + 1) + "&#39;>下一页</a> "; 
str += "<a href=&#39;" + fileName + temp + "cur_page=" + pageCount + "&#39;>尾页</a> "; 
} 
str += " 共<b>" + rowsCount + "</b>条记录 "; 
str += " 转到<select name=&#39;page&#39; onChange="location=&#39;" + fileName 
+ temp + "cur_page=&#39;+this.options[this.selectedIndex].value">"; 
for (int i = 1; i <= pageCount; i++) { 
if (i == curPage) 
str += "<option value=&#39;" + i + "&#39; selected>第" + i + "页</option>"; 
else 
str += "<option value=&#39;" + i + "&#39;>第" + i + "页</option>"; 
} 
str += "</select></p></form>"; 
return str; 
} 
}

を実装するクラスPageResultSetです。 以下はページング

/* 
* Generated by MyEclipse Struts 
* Template path: templates/java/JavaClass.vtl 
*/ 
package struts.action; 
import java.util.Collection; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 
import org.apache.struts.action.Action; 
import org.apache.struts.action.ActionForm; 
import org.apache.struts.action.ActionForward; 
import org.apache.struts.action.ActionMapping; 
import page.bean.DatabaseConn; 
import page.bean.PageResultSet; 
import page.bean.ContactBO; 
import struts.form.LoginForm; 
/** 
* MyEclipse Struts 
* Creation date: 04-02-2008 
* 
* XDoclet definition: 
* @struts.action path="/login" name="loginForm" input="/login.jsp" scope="request" validate="true" 
* @struts.action-forward name="sss" path="/index.jsp" 
*/ 
public class LoginAction extends Action { 
/* 
* Generated Methods 
*/ 
/** 
* Method execute 
* @param mapping 
* @param form 
* @param request 
* @param response 
* @return ActionForward 
*/ 
public ActionForward execute(ActionMapping mapping, ActionForm form, 
HttpServletRequest request, HttpServletResponse response) { 
LoginForm loginForm = (LoginForm) form; 
ContactBO userBO=new ContactBO(); 
//先从业务处理逻辑类中取出数据(ArrayList或Vector格式) 
Collection data; 
try { 
data = userBO.findContact(DatabaseConn.getConnection()); 
//再得到当前页curPage和每页记录数pageSize 
//int curPage = Integer.parseInt((String)request.getParameter("cur_page")); 
int curPage = 1; 
String cur = request.getParameter("cur_page"); 
System.out.println("--------------: "+cur); 
if(cur!=null && cur !=""){ 
curPage = new Integer(cur).intValue(); 
} 
int pageSize=10; 
//然后生成PageResultSet对象 
PageResultSet dataList = new PageResultSet(data, curPage, pageSize); 
request.setAttribute("usersList", dataList); 
return mapping.findForward("sss"); 
} catch (Exception e) { 
e.printStackTrace(); 
return mapping.getInputForward(); 
} 
} 
}

を表示するページです。

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