public class Test11 {
public static final String DRIVER = "com.mysql.jdbc.Driver";
public static final String URL = "jdbc:mysql://localhost:3306/MySQL";
public static final String USERNAME = "root";
public static final String PASSWORD = "saber";
Connection connection = null;
PreparedStatement preparedStatement = null;
ResultSet resultSet = null;
public Connection getConnection() throws Exception {
Class.forName(DRIVER);
connection = DriverManager.getConnection(URL,USERNAME,PASSWORD);
System.out.println("连接成功");
return connection;
}
public ResultSet executeQuery(String sql) throws Exception {
connection = this.getConnection();
preparedStatement = connection.prepareStatement(sql);
resultSet = preparedStatement.executeQuery();
return resultSet;
}
public int executeUpdate(String sql,Object[] obj) throws Exception {
connection = this.getConnection();
preparedStatement = connection.prepareStatement(sql);
for(int i =0;i<obj.length;i++){
preparedStatement.setObject(i+1, obj[i]);
}
return preparedStatement.executeUpdate();
} //这一段代码能不能帮忙解释一下,这样写的作用。不是很理解~
public void closeAll() throws Exception {
if(null != resultSet){
resultSet.close();
}
if(null != preparedStatement){
preparedStatement.close();
}
if(null != connection){
connection.close();
}
}
新手,有点不懂这段代码我标的部分的意义,请逐句解释下,求指导。