推薦：解析Jsp常用技巧:圖片驗(yàn)證碼
思路 ： 圖片驗(yàn)證碼的實(shí)現(xiàn)主要的技術(shù)點(diǎn)是如何生成一個(gè)圖片。生成圖片可以使用java.awt包下的類來(lái)實(shí)現(xiàn)。我們先寫(xiě)一個(gè)簡(jiǎn)單的生成圖片的程序HelloImage.java。以下是代碼部分。 package com.vogoal.test; import java.awt.Color; import java.awt.Graphics; imp

一、建立數(shù)據(jù)庫(kù)分頁(yè)的類

package newsbean;
import java.sql.*;

public class DBConnection{
//這里使用ms jdbc
String sDBDriver = "com.microsoft.jdbc.sqlserver.SQLServerDriver";
//指定數(shù)據(jù)庫(kù)名/url
private final String url = "jdbc:microsoft:sqlserver://";
private final String serverName= "localsqlserver";
private final String portNumber = "1433";
private final String databaseName= "MyBusiDB";
//String sConnStr = "jdbc:microsoft:sqlserver://localsqlserver:1433;DatabaseName=ourcompany";
private final String dbUserName = "sa";
private final String dbPassword = "111111";
// Informs the driver to use server a side-cursor,
// which permits more than one active statement
// on a connection.
private final String selectMethod = "cursor";

Connection conn = null;
ResultSet rs = null;
Statement stmt = null;

//這三個(gè)參數(shù)用于記錄翻頁(yè)
int iRowCount = 0; //返回總行數(shù)
int iPageCount = 0; //返回總頁(yè)數(shù)
int iPage = 0;

public DBConnection(){
try
{
Class.forName(sDBDriver);
}
catch(ClassNotFoundException e)
{
System.err.println("DBConnection():" + e.getMessage());
}
}

//構(gòu)造一個(gè)連接字符串
private String getConnectionUrl(){
return url+serverName+":"+portNumber+";databaseName="+databaseName+";selectMethod="+selectMethod+";";
}

//================考慮在類中的分頁(yè)======================================
//內(nèi)部設(shè)置總條數(shù)..
private void setRowCount(int irowcount)
{
this.iRowCount = irowcount;
}
//返回內(nèi)部設(shè)置的總條數(shù)
public int getRowCount()
{
return this.iRowCount;
}

//內(nèi)部設(shè)置總頁(yè)數(shù)..
private void setPageCount(int ipagecount)
{
this.iPageCount = ipagecount;
}
//返回內(nèi)部設(shè)置的總頁(yè)數(shù)
public int getPageCount()
{
return this.iPageCount;
}

//內(nèi)部設(shè)置當(dāng)前頁(yè)..
private void setPage(int ipage)
{
this.iPage = ipage;
}
//返回內(nèi)部設(shè)置的總頁(yè)數(shù)
public int getPage()
{
return this.iPage;
}
//顯示翻頁(yè)信息
//參數(shù)：總頁(yè)數(shù),總行數(shù)，當(dāng)前頁(yè)
//應(yīng)該考慮加一個(gè)查詢參數(shù)列表進(jìn)入本方法--2007-4-12
public String showChangePage()
{
return this.iPage + "/" + this.iPageCount + ">>>";
}

//考慮了翻頁(yè)的選擇查詢
public ResultSet execQuery(String sql,int iPageSize,int iPage)
{//======iRowCount== iPageCount==iPageSize===iPage================
try
{
conn = DriverManager.getConnection(getConnectionUrl(),dbUserName,dbPassword);
stmt = conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
rs = stmt.executeQuery(sql);
rs.last();

//獲取總行數(shù) 移動(dòng)到最后，檢索當(dāng)前行編號(hào)。
int iRowCount= rs.getRow();
//計(jì)算總頁(yè)數(shù) 總100行 每頁(yè)10行===〉總頁(yè)數(shù)= 11.4頁(yè)==> 12頁(yè)
int iPageCount = (iRowCount + iPageSize-1) / iPageSize;
if(iPage>iPageCount) iPage = iPageCount;
if(iPage <= 0 ) iPage = 1;
if(iPageCount>0){
//在方法體中已經(jīng)到了指定行
rs.absolute((iPage-1) * iPageSize +1);
}
//自己設(shè)置iPageCount和iRowCount,iPage，避免混淆？！
setPageCount(iPageCount);
setRowCount(iRowCount);
setPage(iPage);
//stmt.close();???
}//end try
catch(SQLException ex)
{
System.err.println("DBConnection.execQuery():" + ex.getMessage());
}//end catch

return rs;

}//end execQuery

//======================================================
//關(guān)閉數(shù)據(jù)庫(kù)
public void closeDB()
{
try
{

//System.out.println("DBConnection.closeDB( here!)" );
if(rs!=null)
{
rs.close();
rs = null;
}
else
{
System.out.println("rs closed!");
}//?????

if(stmt!=null)
{
stmt.close();
stmt = null;
}
else
{
System.out.println("stmt closed!");
}
if(conn!=null)
{
conn.close();
conn = null;
}
else
{
System.out.println("conn closed!");
}
}
catch(Exception ex)
{
//System.err.println("DBConnection.closeDB()" + ex.getMessage());
System.out.println("DBConnection.closeDB()" + ex.getMessage());
}
}

}//end Class
--------------------------------------------------------------------------------------------------------------

二、jsp程序中使用本類過(guò)程
1、<jsp:useBean id="conn" class="newsbean.DBConnection" />
2、處理查詢參數(shù)iPage ,txtSearchKeyword等
3、文章列表：

int iPageSize = 15;//每次讀行數(shù)，作為參數(shù)傳入<jsp:setProperty id......沒(méi)用上！
String sql=null;
ResultSet rs =null;
int iRowCount = 0;
int iPageCount = 0;
try{
//===========================
int i = 0;
//l構(gòu)造sql語(yǔ)句。。。
sql="SELECT top 200 number, sms_no, company_card_name, Reg_Date, Dead_Date, OnUse, province, "
+ "City FROM dbo.Company_Card where 1=1 " ;
if(!( txtSearchCompanyCard.equals("")))sql = sql + " and company_card_name like '%" + txtSearchCompanyCard + "%'";
if(!( txtSearchCity.equals("")))sql = sql + " and City ='" + txtSearchCity + "'";
sql = sql + " order by number desc ";

//取得resultset
rs = conn.execQuery(sql,iPageSize,iPage);

//獲取記錄總數(shù)
iRowCount = conn.getRowCount();
//獲取總頁(yè)數(shù)
iPageCount = conn.getPageCount();

//循環(huán)
do{
%>
<tr>
<td>[<%=rs.getRow()%>]</td>
<td><%=rs.getString("sms_no")%></td>
<td><%=rs.getString("company_card_name")%></td>
<td><%=rs.getDate("Reg_Date")%></td>
<td><%=rs.getString("province")%></td>
<td><%=rs.getString("City")%></td>
<td><a href="#" onclick="return domodify('<%=rs.getInt("number")%>')">修改</a></td>
</tr>
<%
}while(++i<iPageSize && rs.next());
}catch(Exception e){
out.print("rs Err:" + e.getMessage());
out.print(sql + "<br/>");
}%>
 

分享：談CSV文件的生成與分析
CSV文件是指Excel可以識(shí)別的后綴名為CSV的文件，網(wǎng)站系統(tǒng)后臺(tái)用來(lái)存儲(chǔ)分析數(shù)據(jù)的時(shí)候有可能會(huì)用到它。其實(shí)CSV文件的讀取和做成比較簡(jiǎn)單，主要的技術(shù)點(diǎn)是文件的讀寫(xiě)。不過(guò)CSV文件的分析和生成有一定的代表性，可以通過(guò)對(duì)CSV文件的生成和分析的實(shí)現(xiàn)，來(lái)了解后