Java连接数据库类

因为写的大作业经常用到数据库连接 所以自己写了个数据库连接的类

package DB_Link_info;
/*
* 数据库链接信息
*/
public class DB_link_Info {
public static final String driverName = "com.microsoft.sqlserver.jdbc.SQLServerDriver";
public static final String dbURL = "jdbc:sqlserver://localhost:1433;DatabaseName=Store+_DB";
public static final String userName="sa";
public static final String userPwd="729757710";
}

数据库链接类
package DB_Link_info;

import java.sql.*;

public class DB_Link {
public Statement sta;
public ResultSet rs;
public Connection con;
public String sql;
public DB_Link() throws Exception{
Class.forName(DB_link_Info.driverName);
con=DriverManager.getConnection(DB_link_Info.dbURL,DB_link_Info.userName,DB_link_Info.userPwd);
sta=con.createStatement();
}
public void close() throws Exception{
if(rs!=null)rs.close();
if(sta!=null)sta.close();
}
public void setSQL(String sql){this.sql=sql;}
public String getSQL(){return this.sql;}
public ResultSet getRS(){
ResultSet rs = null;
try {
rs = sta.executeQuery(sql);
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.print("SQL语言错误");
}
return rs;
}
public ResultSetMetaData getRSMD(){
ResultSetMetaData rsmd = null;
try {
rsmd = rs.getMetaData();
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.print("获取数据结果集错误");
}
return rsmd;
}
public void execQuery(){
try {
sta.executeQuery(sql);
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.print("插入或跟新失败");
}
}
}比如说在登录界面 需要连接数据库 我是这样做的 先定义一个成员变量DB_Link
private DB_Link dbl = new DB_Link();然后需要的时候 先设置DB_Link的成员变量sql 再执行该类的其它方法
dbl.setSQL("select * from logon_users_info");
ResultSet rs=dbl.getRS();最后用该类的关闭方法关闭连接
dbl.close();