java无数据源连接Access数据库实例

  1.连接数据库ConnDB()类
package tool;
/****************************
**
**属性文件与数据库均在tool包下面
**
*****************************/
/* 数据访问组件 */
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
public class ConnDB{
private static ConnDB instance=null;
String db_driver=null;
String db_url=null;
String db_user=null;
String db_psw=null;
String db_name=null;
String proPath="conn.properties";
Connection conn=null;
public ConnDB(){
InputStream in=getClass().getResourceAsStream(proPath);
Properties prop=new Properties();
try {
prop.load(in);
db_driver=prop.getProperty("db_driver",db_driver);
db_url=prop.getProperty("db_url",db_url);
db_user=prop.getProperty("db_user",db_user);
db_psw=prop.getProperty("db_psw", db_psw);
db_name=prop.getProperty("db_name",db_name);

db_url=db_url+getDBPath();
} catch (IOException e) {
e.printStackTrace();
}
}
//获得安全连接
public synchronized Connection getConnection(){
if(instance==null){
instance=new ConnDB();
}
return instance._getConnection();
}
//释放资源
public static void dbClose(Connection conn,PreparedStatement ps,ResultSet rs){
try{
if(rs!=null){
rs.close();
}
if(ps!=null){
ps.close();
}
if(conn!=null){
conn.close();
}
}catch(SQLException e){
e.printStackTrace();
}
}
//创建连接
private Connection _getConnection() {
try {
Class.forName(db_driver).newInstance();
conn=DriverManager.getConnection(db_url, db_user, db_psw);
} catch (Exception e) {
e.printStackTrace();
}
return conn;
}
//返回数据库的绝对路径
public String getDBPath(){
String dbpath=getClass().getResource(db_name).getFile();
dbpath=db