beandbtest.java

一本jsp自学教材

package test;
import java.sql.*;
public class BeanDBtest
{
  //驱动名
  private String driverName="com.mysql.jdbc.Driver";
  //数据库用户名
  private String userName="root";
  //密码
  private String userPasswd="yesterdayn";
  //数据库名
  private String dbname="study";
  //表名
  String tableName="";

  public BeanDBtest()
   {
      try{
      Class.forName("com.mysql.jdbc.Driver");
      }
      catch(ClassNotFoundException e){}  
   }
 //设置表名 
public void setTableName(String n)
  {
   this.tableName=n;         
  } 

public StringBuffer getBuffer()
{
  StringBuffer buffer=new StringBuffer();
 try{
  String url="jdbc:mysql://localhost/"+dbname+"?useUnicode=true&characterEncoding=UTF-8&user="+userName+"&password="+userPasswd;
   
  Connection connection=DriverManager.getConnection(url);
  Statement statement = connection.createStatement();
  
  String sql="SELECT * FROM "+tableName;
  ResultSet rs = statement.executeQuery(sql);

   buffer.append("<table border=1>");   
   buffer.append("<TR><TD>序号</TD><TD>用户名</TD><TD>年龄</TD><TD>QQ</TD></TR>");

   int i=0;
   while(rs.next())
     {
    i++;
    String username=rs.getString("username");
    int age=rs.getInt("age");
    String qq=rs.getString("qq");
   
    buffer.append("<TR><TD>"+i+"</TD><TD>"+username+"</TD>");
    buffer.append("<TD>"+age+"</TD><TD>"+qq+"</TD></TR>");
    }
  buffer.append("</table>");   
  rs.close();   
  statement.close();   
  connection.close();
   }
 catch(SQLException e){} 
  return buffer;
}
}