import java.sql.*;
import java.util.*;

public final class Mysql{
 private Connection conn = null;
// private Statement st = null;

 ArrayList res = new ArrayList();
 private PreparedStatement ps = null;
 private ResultSet rs = null;
 private String url = "jdbc:sql>mysql://localhost:3306/test";
 private String user = "root";
 private String passwd = "";
 private static final String name = "com.sql>mysql.jdbc.Driver";
// private String driver = "org.gjt.mm.sql>mysql.Driver";
 
 static {
  try{
  // com.sql>mysql.jdbc.Driver d = new com.sql>mysql.jdbc.Driver();
   Class.forName(name);
  // DriverManager.registerDriver(new com.sql>mysql.jdbc.Driver());
  }catch(ClassNotFoundException cnfe){
   cnfe.printStackTrace();
  }
 }

 public Connection getConn(){
  try{
   conn = DriverManager.getConnection(url,user,passwd);
  }catch(SQLException sqle){
   conn = null;
   sqle.printStackTrace();
  }finally{
   return conn;
  }
 }

 public ArrayList getRs(String sql){
  try{
//   st = conn.createStatement();
   conn = getConn();
   ps = conn.prepareStatement(sql);
   rs = ps.executeQuery();
   System.out.println(conn);
   if(rs != null){
    while(rs.next()){
     ArrayList record = new ArrayList();
       record.add(rs.getInt("id"));
        record.add(rs.getString("name"));
           record.add(rs.getString("sex"));
           record.add(rs.getString("hobby"));
     res.add(record);
       }
   }
  }catch(SQLException sqle){
   sqle.printStackTrace();
  }finally{
   try{
    if(rs != null){
     rs.close();
    } 
   }catch(SQLException sqle){
    sqle.printStackTrace();
   }
   return res;
  }
 }
 
 public ArrayList getRs(ArrayList al, int id){
  ArrayList tmp = null;
  for(int i=0; i<al.size(); i++){
   if(id == ((ArrayList)al.get(i)).get(0)){
    tmp = (ArrayList)al.get(i);
   }
  }
  return tmp;
 }

 public void closeAll(){
  try{
   if(rs != null){
    rs.close();
   } 
  }catch(SQLException sqle){
   sqle.printStackTrace();
  }finally{
   try{
    if(ps != null){
     ps.close();
    }
   }catch(SQLException sqle){
    sqle.printStackTrace();
   }finally{
    try{
     if(conn != null){
      conn.close();
     }
    }catch(SQLException sqle){
     sqle.printStackTrace();
    }
   }
  }
 }

 public void showRs(ArrayList al){
   if(al != null){
            for(int i=0; i<al.size(); i++){
            System.out.print(((ArrayList)al.get(i)).get(0) + "  ");
                System.out.print(((ArrayList)al.get(i)).get(1) + "  ");
             System.out.print(((ArrayList)al.get(i)).get(2) + "  ");
             System.out.print(((ArrayList)al.get(i)).get(3) + "  ");
             System.out.println(" ");
         }  
     }  
 }
}

---

import java.sql.*;
import java.util.*;
public class Test{
 public static void main(String[] args){
  
  Mysql m = new Mysql();
//  m.init();
  String sql = "SELECT * FROM stu";
  ArrayList rs = m.getRs(sql);
  if(rs != null){
  System.out.println(rs.size());
   for(int i=0; i<rs.size(); i++){
    System.out.print(((ArrayList)rs.get(i)).get(0) + " ");
    System.out.print(((ArrayList)rs.get(i)).get(1) + " ");
    System.out.print(((ArrayList)rs.get(i)).get(2) + " ");
    System.out.print(((ArrayList)rs.get(i)).get(3) + " ");
    System.out.println(" ");
   }
  }
  ArrayList a = m.getRs(rs,3);
  if(a != null){
   for(int j=0 ;j<4; j++){
    System.out.println(a.get(j)+" ");
   }
  }
  m.closeAll();
 }
}

来自：http://chenhongbin007.blog.163.com/blog/static/34069921200932691146498/