//操作数据库的公共类
public class BaseDao {
private static String driver;
private static String url;
private static String username;
private static String password;
//静态代码块
static {
Properties properties = new Properties();
//通过类加载器读取对应的资源
InputStream is = BaseDao.class.getClassLoader().getResourceAsStream("dp.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");
}
//获取数据库的链接
public static Connection getConnection(){
Connection connection =null;
try {
Class.forName(driver);
connection = DriverManager.getConnection(url, username, password);
} catch (Exception e) {
e.printStackTrace();
}
return connection;
}
//编写查询公共类
public static ResultSet execute( Connection connection,String sql,Object[]params,ResultSet resultSet) throws SQLException {
//预编译的sql,在后面直接执行就可以了
PreparedStatement preparedStatement =connection.prepareStatement(sql);
for(int i =0; i<params.length;i++){
preparedStatement.setObject(i+1,params[i]);
}
resultSet =preparedStatement.executeQuery();
return resultSet;
}
//编写增删改公共方法
public static int execute(Connection connection,String sql,Object[] params,PreparedStatement preparedStatement) throws SQLException {
//预编译的sql,在后面直接执行就可以了
preparedStatement = connection.prepareStatement(sql);
for(int i =0; i< params.length; i++){
preparedStatement.setObject(i+1,params[i]);
}
int updateRows = preparedStatement.executeUpdate(sql);
return updateRows;
}
//释放资源
public static boolean closeResource(Connection connection,PreparedStatement preparedStatement,ResultSet resultSet) {
boolean flag = true;
if (resultSet != null) {
try {
resultSet.close();
resultSet = null;
} catch (SQLException e) {
e.printStackTrace();
flag = false;
}
}
if (preparedStatement != null) {
try {
preparedStatement.close();
preparedStatement = null;
} catch (SQLException e) {
e.printStackTrace();
flag = false;
}
}
if (connection != null) {
try {
connection.close();
connection = null;
} catch (SQLException e) {
e.printStackTrace();
flag = false;
}
}
return flag;
}
}