smbms项目搭建

 

数据库公共类代码，实际上就是将获取数据库连接以及增删改查资源关闭等操作进行封装，调用时就不必再进行重复操作

 

public class BaseDao {
    private   static String url;
    private  static String username;
    private  static String password;
    private  static String driver;




    static {
        Properties properties = new Properties();
        InputStream is = BaseDao.class.getClassLoader().getResourceAsStream("db.properties");
        try {
            properties.load(is);
        } catch (IOException e) {
            e.printStackTrace();
        }
        driver = properties.getProperty("driver");
        url= properties.getProperty("url");
        username= properties.getProperty("username");
        password= properties.getProperty("password");
    }
public Connection getConnection() {
        Connection connection=null;
    try {
        Class.forName("driver");
       connection = DriverManager.getConnection(url, username, password);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return connection;
}
public static ResultSet execute(PreparedStatement preparedStatement ,Connection connection,Object[] params,String sql,ResultSet resultSet ) throws SQLException {
        preparedStatement= connection.prepareStatement(sql);
        for (int i = 0; i < params.length; i++) {
            preparedStatement.setObject(i + 1, params[i]);
        }
        resultSet = preparedStatement.executeQuery();
        return resultSet;
}
 public static int execute(PreparedStatement preparedStatement,Connection connection,Object[] params,String sql) throws SQLException {
     preparedStatement= connection.prepareStatement(sql);
     for (int i = 0; i <params.length ; i++) {
         preparedStatement.setObject(i+1,params[i]);
     }
     int hi = preparedStatement.executeUpdate();
     return hi;
 }
 public boolean closeResource(PreparedStatement preparedStatement,Connection connection,ResultSet resultSet){
        boolean h=true;
        if (resultSet!=null){
            try {
                resultSet.close();
                resultSet=null;
            } catch (SQLException e) {
                e.printStackTrace();
                h=false;
            }
        }
     if (connection!=null){
         try {
             connection.close();
             connection=null;
         } catch (SQLException e) {
             e.printStackTrace();
             h=false;
         }
     }
     if (preparedStatement!=null){
         try {
             preparedStatement.close();
             preparedStatement=null;
         } catch (SQLException e) {
             e.printStackTrace();
            h=false;
         }
     }
     return h;
 }
}