viewthinglistaction.java

此资源是jsp应用开发 邓子云等编写的一书里的源代码

package action;
import java.sql.Connection;
import java.sql.ResultSet;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;

import org.apache.struts.action.Action;
import org.apache.struts.action.ActionErrors;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.action.ActionMessage;

/**
 * @author dengziyun
 * 登录的Action类
 */
public class viewThingListAction extends Action{
	
	/**
	 * 在此方法中处理HTTP请求，并作响应
	 */
	public ActionForward execute(ActionMapping arg0, ActionForm arg1,
			HttpServletRequest request, HttpServletResponse reponse) throws Exception {
		int diPage=1;//当前页码
		int pageSize=10;//每页显示的记录条数
	  	int allRecordCount=0;//记录总条数
	  	int pageRecordCount=0;//当前页记录条数
	  	int pageCount=0;//总页数
		ActionErrors errors=new ActionErrors();
		String diPageStr=request.getParameter("diPage");
		//------没有传来当前页码，则默认为1------
		if(diPageStr==null||diPageStr.trim().length()<1)
			diPage=1;
		//------防止传来的数据有误，默认为1------
	  	try{
	  		diPage=Integer.parseInt(request.getParameter("diPage"));
	  	}catch(Exception e){
	  		diPage=1;
	  	}
	  	//------查询出数据，将查询结果数据集写入到response中------
	  	try{
			//------得到数据库连接------
			Context initCtx = new InitialContext(); 
			Context ctx = (Context) initCtx.lookup("java:comp/env");
			Object obj = (Object) ctx.lookup("jdbc/sqlserver");
			DataSource ds = (javax.sql.DataSource)obj;
			Connection conn = ds.getConnection();
			//------查询数据------
			//------构造查询的SQL语句------
		  	//sqlStr1为查询到当前页数据的SQL语句
		  	//sqlStr2为查询到总记录条数的SQL语句
		  	String sqlStr1="select top "+diPage*pageSize+" * from thing where "+
		  		"thingId not in (select top "+(diPage-1)*pageSize+" thingId from"+
		  		" thing order by thingId desc) order by thingId desc"; 		
		  	String sqlStr2="select count(*) as allCount from thing";
            //------得到总页数、总记录条数与当前页记录条数------
		  	java.sql.Statement sql1=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE, ResultSet.CONCUR_READ_ONLY);
		  	java.sql.ResultSet rs1=null;
		  	rs1=sql1.executeQuery(sqlStr2);
		  	if(rs1!=null){
		  		//---得到总页数、总记录条数与当前页记录条数---
		  		rs1.next();
		  		allRecordCount=rs1.getInt("allCount");
		  		if(allRecordCount%pageSize==0)
		  			pageCount=allRecordCount/pageSize;
		  		else
		  			pageCount=(int)(allRecordCount/pageSize)+1;
		  		if(diPage==pageCount||pageCount==0)//最后一页或没有数据
		  			pageRecordCount=allRecordCount-(diPage-1)*pageSize;
		  		else
		  			pageRecordCount=pageSize;
		  	}
            //------得到当前面数据------
		  	java.sql.ResultSet rs2=null;
		  	java.sql.Statement sql2=conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
		  	rs2=sql2.executeQuery(sqlStr1);
		  	Object[][] rsArray=new Object[pageRecordCount][4];
		  	int i=0;
		  	while(rs2.next()){
		  		rsArray[i][0]=rs2.getString("thingId");
		  		rsArray[i][1]=rs2.getString("thingTitle");
		  		rsArray[i][2]=rs2.getString("thingContent");
		  		rsArray[i][3]=rs2.getString("thingAddTime");
		  		i++;
		  	}
		  	//------将所有数据写入到request------
		  	request.setAttribute("diPage",new Integer(diPage));
		  	request.setAttribute("pageSize",new Integer(pageSize));
		  	request.setAttribute("allRecordCount",new Integer(allRecordCount));
		  	request.setAttribute("pageRecordCount",new Integer(pageRecordCount));
		  	request.setAttribute("pageCount",new Integer(pageCount));
		  	request.setAttribute("rsArray",rsArray);
		  	//------关闭数据库连接------
		  	if(conn!=null)
		  		conn.close();
		}catch(Exception e){
			e.printStackTrace();
			errors.add("DBOPError",new ActionMessage("DBOPError"));
			saveErrors(request,errors);
		}
		return arg0.findForward("viewThingListJSP");
	}
}