06_ Data type conversion
Chapter 6 data type conversion
Author: Zhang Zimo
Java programs require that the data involved in calculation must be consistent in data types. If the data types are inconsistent, type conversion will occur.
1, Automatic conversion
What data type will result from the addition of an int variable and a byte variable?
int i = 1;
byte b = 2; ...
Posted by sparq on Mon, 20 Sep 2021 10:39:43 -0700
Build the mybatis framework, complete the addition, deletion, modification and query of single table, and test
One. MySQL database is used. Create a new database named task and a new table named student in the task database. Add data to the table as appropriate. The SQL statements and tables for creating tables and adding data are as follows.
--Create table
DROP TABLE IF EXISTS `student`;
CREATE TABLE `student` (
`sid` varchar(40) NOT NULL DEFAULT '' ...
Posted by lprocks on Mon, 20 Sep 2021 07:46:32 -0700
1 - inheritance, template design pattern, abstract class, final
preface
Tip: here are the knowledge points of inheritance, abstract classes, template design patterns and final keywords
Tip: the following is the main content of this article. The following cases can be used for reference
1, Inherit
Overview: a class inherits from another class. This class is a child class, and the inherited class ...
Posted by AwptiK on Sat, 18 Sep 2021 03:17:27 -0700
javaEE note administrator login
index.jsp in the web Directory:
<%--
Created by IntelliJ IDEA.
User: Administrator
Date: 2017/12/25/025
Time: 20:40
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>$Tit ...
Posted by shadow_blade47 on Thu, 30 Apr 2020 16:17:20 -0700
The use of FilterConfig in Servlet
Original link: http://www.yiidian.com/servlet/filter-config.html
The Web container creates an object for FilterConfig. This object can be used to get the configuration information of the Filter from the web.xml file.
1. Method of filterconfig interface
There are four methods in the FilterConfig interface:
public void init (FilterConfig config) ...
Posted by daiwa on Mon, 20 Apr 2020 08:38:07 -0700
Various path issues for Request requests
From: https://blog.csdn.net/qq_27770257/article/details/79438987
Recently, there has been some confusion about several "paths" in request, and the search for online resources is not well summarized. I hope this article can help me understand these "paths".(+++++++++++++++++++++++++++++++++++++++++++++++++ T ...
Posted by benutne on Wed, 25 Mar 2020 09:32:39 -0700
Day 31 of learning Java -- byte stream of IO framework
Concept of stream, classification of stream, byte stream, serialization
15. I/O framework
15.1 concept of flow
15.2 classification of flows
15.2.1 flow classification (direction)
15.2.2 flow classification (unit, function)
15.3 byte stream
15.3.1 parent class of byte stream
15.3.2 byte node strea ...
Posted by kenrbnsn on Mon, 16 Mar 2020 06:44:14 -0700
Servlet forward and include methods
Original link: http://www.yiidian.com/servlet/servlet-dispatcher.html
Request Forwarding and Inclusion Using Servlet
The RequestDispatcher interface provides the ability to forward requests to another resource, which may be Html, Servlet, or Jsp.The interface can also be used for content containing other resources.
Method of 1 RequestDispatcher ...
Posted by stevengunn on Sat, 14 Mar 2020 15:55:00 -0700
SpringBoot -- Schedule Tasks
Starting with Spring 3.1, the implementation of scheduled tasks in Spring has become unusually simple.First turn on support for scheduled tasks by configuring the class annotation @EnableScheduling, then annotate @Scheduled on the method of executing the collection task to declare that this is a scheduled task.
Spring supports a variety of sche ...
Posted by wilzy on Fri, 14 Feb 2020 09:07:13 -0800
Java Web advanced filter
Filter
Chapter 1 basic use of filter
1. Initial filter
Filter - filter:
Filter is a component of J2EE Servlet module
The function of Filter is to block URL s in a unified way
Filter is usually used for global processing at the application level
Three elements of filter development:
*Any filt ...
Posted by robot43298 on Wed, 29 Jan 2020 06:47:14 -0800