JSP实战型程序连载:通用数据库连接JavaBean

package online;

 

import java.sql.*;

 

public class DBConn {

  private static String rootpath = "web发布路径";

  private String sample = "sample";

  private Connection con = null;

  private Statement stmt = null;

  ResultSet rs = null;

  /***************************************************************/

  private static final String DRIVE = "sun.jdbc.odbc.JdbcOdbcDriver";

  //暂时使用jdbc-odbc连接//"com.microsoft.jdbc.sqlserver.SQLServerDriver";

  private static final String USERNAME = "sa";

  private static final String PASSWORD = "123aaa";

  private static final String HOST = "http:127.0.0.1:8080/renshi";

  /*************************************************************/

  //暂时使用jdbc-odbc数据源

  private static final String CONNECTION_STRING = "jdbc:odbc:renshi";

  //"jdbc:microsoft:sqlserver://localhost;1433;";

  public static String getRootPath() {

    return rootpath;

  }

 

  public DBConn() { //加载驱动

    try {

      Class.forName(DRIVE);

    }

    catch (ClassNotFoundException e) {

      System.err.println("DBConn():" + e.toString());

    }

    catch (Exception e) {

      System.err.println("DBConn():" + e.toString());

    }

  }

 

  public Connection getConnection() { //得到连接

    try {

      String strUrl = CONNECTION_STRING;

      /***********周五晚改动****************************************/

      //+ "DatebaseName=renshi," + USERNAME +"," + PASSWORD;

      con = DriverManager.getConnection(strUrl, this.USERNAME, this.PASSWORD);

    }

    catch (Exception e) {

      con = null;

    }

    return con;

  }

 

  public void dropConnection() { //关闭连接

    try {

      closeStmt();

      con.close();

    }

    catch (Exception ignored) {

    }

    finally {

      con = null;

    }

  }

 

  public ResultSet executeQuery(String sql) { //执行sql查询

    ResultSet rs = null;

    try {

      con = getConnection();

      stmt = con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,

                                 ResultSet.CONCUR_READ_ONLY);

      rs = stmt.executeQuery(sql);

    }

    catch (SQLException ex) {

      System.err.println("DBConn.executeQuery():" + ex.getMessage());

    }

    return rs;

  }

 

  public int executeUpdate(String sql) { //执行sql更新语句

    int i=0;

    stmt = null;

    rs = null;

    try {

      con = getConnection();

      stmt = con.createStatement();

     i= stmt.executeUpdate(sql);

      stmt.close();

      con.close();

    }

    catch (SQLException ex) {

      System.err.println("DBConn:executeUpdate(0:" + ex.getMessage());

    }

    return i;

  }

 

  public void execute(String sql) { //执行sql语句

    stmt = null;

    rs = null;

    try {

      con = getConnection();

      stmt = con.createStatement();

      stmt.execute(sql);

      stmt.close();

      con.close();

    }

    catch (SQLException ex) {

      System.err.println("DBConn:excute():" + ex.getMessage());

    }

  }

 

  public void closeConn() { //关闭sql连接

    try {

      stmt.close();

    }

    catch (SQLException e) {

      e.printStackTrace();

    }

  }

 

  public void closeStmt() { //关闭sql连接

    try {

      con.close();

    }

    catch (SQLException e) {

      e.printStackTrace();

    }

 

  }

 

  /**

   * main

   */

  public static void main(String[] args) throws SQLException {

    DBConn one=new DBConn();

    ResultSet rs=one.executeQuery("select * from PS_INFO");

    while(rs.next()){

      System.out.println(rs.getString(2));

    }

  }

 

}