编写 Servlet 程序 - 3
前面已经写了两篇博文，今天通过已做的项目（v1.1）为完结篇。
项目的要求:把已存在的数据通过网页，呈现给客户，主要功能为查询。
code：
import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; // import java.io.*; //import java.util.*; import java.sql.*; /** * Servlet implementation class for Servlet: pastTimeList * @author xiaobin * @date 2007.12.23 * @version 1.1 */ public class pastTimeList extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet { static final long serialVersionUID = 1L; /* (non-Java-doc) * @see javax.servlet.http.HttpServlet#HttpServlet() */ public pastTimeList() { super(); } /* (non-Java-doc) * @see javax.servlet.http.HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub //设置 网页头 response.setContentType("text/html; charset=GBK"); //声明 PrintWriter PrintWriter out=new PrintWriter(response.getOutputStream()); //Properties props=new Properties(); //输出 网页代码 out.println("<html>"); out.println("<head><title>车号过车列表</title></head>"); out.println("<h2><center>"); out.println("车号详细列表"); out.println("</center></h2>"); out.println("<br>");//换行 String sURIstr="http://localhost:9090/CarNumber/pastTimeList";//声明 servlet uri out.println("<form method=POST action=/"" +sURIstr +"/">选择过车时间"); out.println("<select name=pastTime size=1>"); //设置 String urlStr="jdbc:jtds:sqlserver://localhost:1433/pubs"; String driverNameStr="net.sourceforge.jtds.jdbc.Driver"; String userNameStr="sa"; String passWordStr="123456"; //输出 下拉框数据 String queryStrB="select DISTINCT past_time from trainOrder order by past_time"; outPastTimeList(driverNameStr, urlStr, userNameStr, passWordStr, //props, queryStrB, out); out.println("</select>"); out.println("<input type=submit value=/" 查询 /">"); out.println("</form>"); //输出 车号数据 String pastTimeStr=request.getParameter("pastTime"); String queryStrA="select seriary_number as 辆序,car_number as 车号," + "car_marque as 车型,carry_weight1 as [标重(吨)],self_weight1 as [自重(吨)],past_time as 过车时间 " + "from trainOrder where past_time='" +pastTimeStr +"' order by seriary_number"; outCarNumber(driverNameStr, urlStr, userNameStr, passWordStr, //props, queryStrA, out); //输出 网页结尾代码 out.println("</body></html>"); //处理 PrintWriter out.flush(); out.close(); } /* (non-Java-doc) * @see javax.servlet.http.HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub this.doGet(request, response); } // private boolean outCarNumber(String driveName, String connectionURL, String userName, String passWord, //Properties props, String queryStr, PrintWriter outPW){ boolean rc=true; Connection conn=null; Statement stmt=null; ResultSet resultSet1=null; long startMS=System.currentTimeMillis(); int rowCount=0; try { Class.forName(driveName).newInstance(); conn=DriverManager.getConnection(connectionURL,userName,passWord); stmt=conn.createStatement(); resultSet1=stmt.executeQuery(queryStr); // rowCount=formatTableCarNum(resultSet1, outPW); } catch (Exception e) { // TODO: handle exception outPW.println("Exception!"); e.printStackTrace(outPW); rc=false; }finally{ try { if(resultSet1!=null) resultSet1.close(); if(conn!=null) conn.close(); if(stmt!=null) stmt.close(); } catch (Exception e2) { // TODO: handle exception } } if(rc){ long elapsed=System.currentTimeMillis()-startMS; outPW.println("<br><i>"+rowCount+"row in"+elapsed+"ms</i>");//输出行数和用时 } return rc; } // private int formatTableCarNum(ResultSet resultSet2, PrintWriter outPW)throws Exception{ int rowCount=0; outPW.println("<center><table border>"); ResultSetMetaData rsmd=resultSet2.getMetaData(); int columnCount=rsmd.getColumnCount(); outPW.println("<tr>"); for (int i = 0; i < columnCount; i++) { outPW.println("<th>" +rsmd.getColumnLabel(i+1) +"</th>"); } outPW.println("</tr>"); //检索数据 while (resultSet2.next()) { rowCount++; outPW.println("<tr>"); for (int i = 0; i < columnCount; i++) { outPW.println("<td>" +resultSet2.getString(i+1) +"</td>"); } outPW.println("</tr>"); } outPW.println("</table></center>"); return rowCount; } //输出下拉框函数与输出车号函数相同，只是输出格式不同 // private boolean outPastTimeList(String driveName, String connectionURL, String userName, String passWord, //Properties props, String queryStr, PrintWriter outPW){ boolean rc=true; Connection conn=null; Statement stmt=null; ResultSet resultSet1=null; int rowCount=0; try { Class.forName(driveName).newInstance(); conn=DriverManager.getConnection(connectionURL,userName,passWord); stmt=conn.createStatement(); resultSet1=stmt.executeQuery(queryStr); // rowCount=formatDropDown(resultSet1, outPW); } catch (Exception e) { // TODO: handle exception outPW.println("Exception!"); e.printStackTrace(outPW); rc=false; }finally{ try { if(resultSet1!=null) resultSet1.close(); if(conn!=null) conn.close(); if(stmt!=null) stmt.close(); } catch (Exception e2) { // TODO: handle exception } } return rc; } // private int formatDropDown(ResultSet resultSet3,PrintWriter outPW)throws Exception{ int rowCount=0; ResultSetMetaData rsmd=resultSet3.getMetaData(); int columnCount=rsmd.getColumnCount(); while (resultSet3.next()) { rowCount++; outPW.print("<option value=/""); // for (int i = 0; i < columnCount; i++) { String pastTimeValueStr=resultSet3.getString(i+1); outPW.print(pastTimeValueStr +"/">" +pastTimeValueStr); } outPW.println("</option>"); } return rowCount; } }