?? dbservlet.java
字號:
package dbservlet;import java.io.*;import java.sql.*;import java.util.*;import javax.servlet.*;import javax.servlet.http.*;/** * Title: 使用Servlet連接數據庫 * Description: 教學示范 * Copyright: Copyright (c) 2003 * Company: 北京師范大學計算機系 * @author 孫一林 * @version 1.0 */public class dbServlet extends HttpServlet { static final private String CONTENT_TYPE = "text/html; charset=GBK"; private Connection connection = null; //定義與數據庫進行連接的Connection對象 private ResultSet rs = null; //定義數據庫查詢的結果集 private Statement statement = null; //定義查詢數據庫的Statement對象 public void init() throws ServletException { //初始化Servlet try { Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); //指定與數據庫連接使用JDBC-ODBC橋驅動程序 } catch(Exception ex) //捕捉異常 { ex.printStackTrace(); } } public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType(CONTENT_TYPE); PrintWriter out = response.getWriter(); String tableName = request.getParameter("tableName"); //獲取用戶要顯示數據的表名 out.println("<html>"); out.println("<head><title>" + tableName + "表中的數據</title></head>"); out.println("<body>"); if (tableName.equals("studentbase")) { out.println("<h2 align=center>學生基本信息表中的數據</h2>"); } else if (tableName.equals("studentaddress")) { out.println("<h2 align=center>學生地址表中的數據</h2>"); } else { out.println("<h2 align=center>選課信息表中的數據</h2>"); } try { String url = "jdbc:odbc:student"; //指定數據源名 connection = DriverManager.getConnection(url); //與數據源建立連接 statement = connection.createStatement(); //創建Statement接口實例 String sql = "select * from " + tableName; //創建取出用戶指定表中所有數據的SQL語句 rs = statement.executeQuery(sql); //將數據存入結果集中 ResultSetMetaData rsData = rs.getMetaData(); //獲取結果集信息 out.println("<table width=75% border=1 align=center><tr>"); for(int i=1; i<=rsData.getColumnCount(); i++) //輸出字段名 { out.println("<td>" + rsData.getColumnLabel(i) + "</td>"); } out.println("</tr>"); while(rs.next()) //輸出表中數據 { out.println("<tr>"); for(int i=1; i<=rsData.getColumnCount();i++) { out.println("<td>" + rs.getString(i) + "</td>"); } out.println("</tr>"); } out.println("</table>"); } catch(SQLException ex){ //捕捉異常 System.out.println("\nERROR:----- SQLException -----\n"); while (ex != null) { System.out.println("Message: " + ex.getMessage()); System.out.println("SQLState: " + ex.getSQLState()); System.out.println("ErrorCode: " + ex.getErrorCode()); ex = ex.getNextException(); } } catch(Exception ex ) { ex.printStackTrace(); } out.println("</body></html>"); } public void destroy() { //當Servlet關閉時釋放資源 try { if(statement != null) { statement.close(); //關閉Statement接口實例 } if(connection != null) { connection.close(); //關閉Connection接口實例 } } catch (SQLException ex) { System.out.println("\nERROR:----- SQLException -----\n"); System.out.println("Message: " + ex.getMessage()); System.out.println("SQLState: " + ex.getSQLState()); System.out.println("ErrorCode: " + ex.getErrorCode()); } }}?? 快捷鍵說明
復制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號
Ctrl + =
減小字號
Ctrl + -