mysqldao.java

建立数据库

package com.song.struts.mySql; 

import javax.swing.JComponent; 
import java.sql.*; 
import java.util.*; 
// import com.borland.dx.sql.dataset.*; 

public class mySqlDao extends JComponent { 
private String UserName="root"; 
private String PWD="root"; 
private String url; 
private Connection cn; 
private Statement stmt; 
private ResultSet rs = null; 
public mySqlDao(){ 
try { 
Class.forName("org.gjt.mm.mysql.Driver"); 
} 
catch(java.lang.ClassNotFoundException e){ 
System.err.println("mydb() org.gjt.mm.mysql.Driver: " + e.getMessage()); 
} 
catch(Exception e) { 
e.printStackTrace(); 
} 

} 
////////////////////////////// 
///返回mysql 连接,connection 
///////////////////////////// 
public Connection Connect(String dbname,String ip){ 
try{ 
String hostip=ip; 
Properties myP = new Properties(); 
myP.setProperty("useUnicode","true"); 
myP.setProperty("characterEncoding","GB2312"); 
url="jdbc:mysql://"+hostip+":3306/"+dbname+"?user="+UserName+"&password="+PWD+""; 
if(cn!=null){ 
cn.close(); 
} 
cn=DriverManager.getConnection(url,myP); 
stmt= cn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_UPDATABLE); 
System.out.println("db connect success"); 
return cn; 
} 
catch(Exception e){ 
System.err.println("db connect err"+e.getMessage()); 
return null; 
} 
} 
////////////////////////////////// 
///关闭连接 
///////////////////////////////// 
public void close(){ 
try{ 
if(stmt!=null){ 
stmt.close(); 
} 
if(cn!=null){ 
cn.close(); 
} 
System.err.println("db colse success"); 
} 
catch(Exception e){ 
System.err.println("db close err"+e.getMessage()); 
} 
} 
///////////////////////////////////////////// 
// 用于进行记录的查询操??,用于select 语句?? 
//参数:sql语句?? 
//返回:ResultSet对象 
/////////////////////////////////////////// 
public ResultSet executeSelect(String sql) { 
try { 
stmt=cn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE); 
rs = stmt.executeQuery(sql); 
return rs; 
} 
catch(SQLException ex) { 
System.err.println("db.executeQuery: " + ex.getMessage()); 
return null; 
} 
} 
////////////////////////////////////////////// 
//用于进行add或???update,insert,del等的记录的操??, 
//入口参数:sql语句 
//返回 :true,false 
////////////////////////////////////////////// 
public boolean executeUpdate(String sql) { 
boolean bupdate=false; 
try{ 
stmt=cn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE); 
int rowCount = stmt.executeUpdate(sql); 
if (rowCount!=0) 
bupdate=true; 
} 
catch(SQLException ex) { 
System.err.println("db.executeUpdate: " + ex.getMessage()); 
} 
return bupdate; 
} 
////////////////////////////////////////////// 
//用于进行表结构的操作,creat drop,modify等??? 
//入口参数:sql语句 
//返回 :true,false 
////////////////////////////////////////////// 
public boolean executeTable(String sql) { 
boolean bupdate=false; 
try { 
stmt= cn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE); 
System.out.print("对表的操作的sqlis :||"+sql+"||"); 
stmt.executeUpdate(sql); 
bupdate=true; 
} 
catch(SQLException ex) { 
System.err.println("db.executeTable: "+ex.getMessage()); 
} 
return bupdate; 
} 
////////////////////////// 
//返回数据库的信息 
////////////////////////// 
public Statement getLWPAIDStatement(){ 
try{ 
return cn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE); 
} 
catch(java.sql.SQLException e){ 
System.err.println("getAISPStatement():"+e.getMessage()); 
return null; 
} 
} 

public DatabaseMetaData getLWPAIDMetaData(){ 
try{ 
return cn.getMetaData(); 
} 
catch(java.sql.SQLException e){ 
System.err.println("getAISPMetaData():"+e.getMessage()); 
return null; 
} 
} 
public static void main(String args[]){ 
mySqlDao a=new mySqlDao(); 
a.Connect("mydb", "localhost"); 
int b=-100; 
ResultSet rs=a.executeSelect("select max(bill_id) from t_bill limit 1"); 
try{ 
while(rs.next()){ 
System.out.println("is in"); 
b=rs.getInt(1); 
} 
}catch(Exception e){ 
e.printStackTrace(); 
} 
System.out.println(b); 
// java.util.Date date=new java.util.Date(); 
// System.out.println(date.toString()); 
// a.executeTable("insert into t_user values(100,'123','1345')"); 
// a.executeTable("update t_user set insert_date='"+date.toString()+"' where user_id=100"); 
a.close(); 

System.out.print(new pub().asc2unicode("??!")); 
} 
}