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JSTL (JSP Standard Tag Library), JSP standard tag library, can be embedded in JSP pages to complete business logic and other functions in the form of tags. The purpose of jstl is to replace script code in jsp page as well as el. JSTL standard tag library has five sub libraries, but with the development, its core library is often used at present ...

MQTT protocol for message sending and receiving in Android PrefaceMQTT (Message Queuing Telemetry Transport), a message protocol based on the publish/subscribe paradigm, is an extremely simple and lightweight message protocol designed for limited devices and networks with low bandwidth, high latency or unreliability.Today we will focus on the u ...

Previously, we talked about the cache control mechanism in http protocol and the introduction of varnish architecture components. Please refer to https://www.cnblogs.com/qiuhom-1874/p/12620538.html Today, let's talk about how to configure and use varnish; We mentioned earlier that there are two configuration files in varnish, one is / etc/varni ...

java Web(cookie) session Technology Set xml configuration information <!-- ************************** --> Create a select -- > < servlet name > demo05 < / servlet name > <! -- 2. Name select -- > < servlet class > come. Lanou3g. Demo05 < / servlet class > &l ...

1. Method 1: 1.1 use filter and ajax setup to intercept ajax and jump to the login page 1 public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) 2 throws IOException, ServletException { 3 4 HttpServletResponse hresponse = (HttpServletResponse)response; 5 HttpServletRequest hr ...

ActiveMQ installation Go to http://activemq.apache.org/ official website to download ActiveMQ Installation environment: 1. jdk required 2. Install the Linux system. The production environment is all Linux systems. Installation steps: Step 1: upload the ActiveMQ compressed package to the Linux system. Step 2: decompress. Step 3: start. Use the ...

Original link of blogger: https://blog.csdn.net/zhengwei223/article/details/30506455 The new thread needs to bind the Hibernate session to use the functions of transaction and delay loading in the new thread, otherwise no session exception will be exposed; terms of settlement: //Business method new Runnable() { @Over ...

1.1 many to many relationship 1.1.1 use annotations to complete many to many configuration. To configure many to many, you only need to configure the intermediate table on one side and use mappedby on the other side to represent foreign key maintenance. A. Create PO class In the Teacher class: @Entity @Table( ...

Hibernate's addition, deletion, modification and query increase There are many ways to add, such as save, persist, savaoroupdate and merge. The use method is as follows. The code here follows the previous section package test; import java.util.Date; import org.hibernate.Session; import org.hibernate.SessionFactory ...

1, Verification code introduction The main way of generation: 1. Use Java Native mode, including the use of Servlet, AWT and ImageIO; 2. Use open source libraries, such as Jcaptcha, Kaptcha; (open source library of each graphic verification code: http://www.oschina.net/project/tag/248/captcha?lang=19) In addition, the generated code can be ...