一个网上购物shoppingcart系统

package com.tarena.util; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.Statement; import java.util.ArrayList; import java.util.List; public class JdbcUtil{ private static ThreadLocal local=new ThreadLocal(); //驱动注册 static{ String d="oracle.jdbc.driver.OracleDriver"; try{ Class.forName(d); }catch(Exception ex){ ex.printStackTrace(); } } //获取连接 public static Connection getConnection(){ Connection con=(Connection) local.get(); if(con==null){ String url="jdbc:oracle:thin:@192.168.0.201:1521:tarena"; String username="openlab"; String password="open123"; try{ con=DriverManager.getConnection(url, username, password); local.set(con); }catch(Exception ex){ ex.printStackTrace(); } } return con; } //释放所有连接 public static void release(ResultSet rs,Statement stmt){ if(rs!=null){try{rs.close();}catch(Exception ex){ex.printStackTrace();}} if(stmt!=null){try{stmt.close();}catch(Exception ex){ex.printStackTrace();}} } //释放某个连接 public static void release(Object o){ try{ if(o instanceof ResultSet){ ((ResultSet)o).close(); }else if(o instanceof Statement){ ((Statement)o).close(); }else if(o instanceof Connection){ ((Connection)o).close(); } }catch(Exception ex){ ex.printStackTrace(); } } public static void releaseCon(){ Connection con=(Connection) local.get(); if(con!=null){ try{ con.close(); local.set(null); }catch (Exception e) { e.printStackTrace(); } } } //获取sql查询后的报表,返回二维数组 public static String[][] getStringArray(ResultSet rs){ if(rs==null){ System.out.println("结果集为空"); return null; } String[][] array=null; List<String[]> list=new ArrayList<String[]>(); try{ ResultSetMetaData md=rs.getMetaData(); int cols=md.getColumnCount(); while(rs.next()){ String[] s=new String[cols]; for(int i=0;i<s.length;i++){ s[i]=rs.getString(i+1); } list.add(s); } array=new String[list.size()][]; for(int i=0;i<list.size();i++){ array[i]=list.get(i); } }catch(Exception ex){ ex.printStackTrace(); } return array; } //打印结果集 public static void printRs(ResultSet rs){ if(rs==null){ System.out.println("结果集为空"); return; } try{ ResultSetMetaData md=rs.getMetaData(); int cols=md.getColumnCount(); StringBuffer sb=new StringBuffer(); //对齐:md.getDisplaySize(i); while(rs.next()){ for(int i=1;i<=cols;i++){ sb.append(md.getColumnName(i)+"="); sb.append(rs.getString(i)+""); } sb.append("\n"); } System.out.println(sb); }catch(Exception ex){ ex.printStackTrace(); } } }