我的JDBC实例

1，  首先在配置文件(system.properties)中配置上如下内容：

driver=com.microsoft.sqlserver.jdbc.SQLServerDriver

url=jdbc:sqlserver://localhost:1433;databaseName=mp

username=sa

password=mengya

2，  写了个SQLDB的工具类

public class SQLDBConnection {

    private InputStream inputstr;

    private Properties pro;

    private static SQLDBConnection sqldb=null;

    //私有构造方法

    private SQLDBConnection(){

       inputstr=this.getClass().getResourceAsStream("/system.properties");

       pro=new Properties();

       try {

           pro.load(inputstr);

       } catch (IOException e) {

           e.printStackTrace();

       }

       try {

           Class.forName(pro.getProperty("driver"));//注册驱动,只注册一次

       } catch (ClassNotFoundException e) {

           e.printStackTrace();

       }

    }

    //单例模式

    public static SQLDBConnection getSQLDBConnection(){

       if(sqldb==null){

           synchronized (SQLDBConnection.class) {

              if(sqldb==null){

                  sqldb=new SQLDBConnection();

              }

           }

       }

       return sqldb;

    }

    //得到与数据库的连接

    public Connection GetConnection(){

       Connection conn=null;

       try {

           conn=DriverManager.getConnection(pro.getProperty("url"), pro.getProperty("username"), pro.getProperty("password"));

       } catch (SQLException e) {

           e.printStackTrace();

       }

       return conn;

    }       3，  写好Studao的接口

   //释放资源

    public static void free(ResultSet rs,Statement sta,Connection conn){

       try{

           if(rs!=null){

              rs.close();

           }

       }catch (Exception e) {

           e.printStackTrace();

       }finally{

           try {

              if(sta!=null){

                  sta.close();

              }

           } catch (Exception e) {

              e.printStackTrace();

           }finally{

              if(conn!=null){

                  try {

                     conn.close();

                  } catch (SQLException e) {

                     e.printStackTrace();

                  }

              }

           }

       }

    }

 

public interface Studaointer {

    public void addStu(Stu stu);

    public void delStu(int sid);

    public void updStu(Stu stu);

    public Stu getOneStu(int sid);

    public List getAllStu();

}

4，  写好自己定义的RuntimeException

public class MySQLException extends RuntimeException {

    private static final long serialVersionUID = 1L;

}

5，  写好Studao的实现类

public class StuDAOImple implements Studaointer {

    private Connection conn;

    private PreparedStatement pre;

    private ResultSet rs;

   

    public void addStu(Stu stu) {

       String sql="insert into stu values(?,?,?)";

       conn=SQLDBConnection.getSQLDBConnection().GetConnection();

       try {

           pre=conn.prepareStatement(sql);

           pre.setString(1, stu.getSname());

           pre.setString(2, stu.getSsex());

           pre.setDate(3, new java.sql.Date(stu.getSbrith().getTime()));

           pre.executeUpdate();

       } catch (SQLException e) {

           e.printStackTrace();

           throw new MySQLException();//异常向上抛

       }finally{

           SQLDBConnection.free(rs, pre, conn);

       }

    }

 

    public void delStu(int sid) {

       String sql="delete stu where s_id=?";

       conn=SQLDBConnection.getSQLDBConnection().GetConnection();

       try {

           pre=conn.prepareStatement(sql);

           pre.setInt(1, sid);

           pre.executeUpdate();

       } catch (SQLException e) {

           e.printStackTrace();

           throw new MySQLException();

       }finally{

           SQLDBConnection.free(rs, pre, conn);