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The singleton pattern guarantees that the object is unique in memory public class Singleton{ private static final Singleton singleObject = new Singleton(); private Singleton(){} public static getSingleton(){ return singleObject; } } The hungry man pattern creates object instances the first time this class is ...

jq's AJAX not only requests network data, but also accesses html and js files across domains. For example, when it accesses js files across domains, it actually does two things: 1. Create < script > tag, src points to the url to be accessed, appendChild() goes to the head tag; 2. Declare function fn, FN must have the same name as the meth ...

Brief concepts of XHProf Native method of re-encapsulating zend If the CPU is to be detected, there will be a 5 ms delay because the CPU frequency needs to be calculated. Internal use of linked lists Source address: / root/Downloads/xhprof/extension/xhprof.c Two of the most important structures /* Xhprof's global state. * * This structure i ...

logging module What is logging module Logging module is a module provided by python for logging Why logging is needed We can open the file by ourselves and write in the log, but these operations are repetitive and without any technical content, so python has packaged it for us. With logging, we only need to simply call the interface when record ...

Preface Homology strategy: judging whether it is homologous, mainly depends on these three points, protocol, ip, port. Homology policy is a policy that browsers restrict the access of resources from different sources for the sake of website security. For example, under the domain name https://www.baidu.com, scripts cannot access resources fr ...

Thank you for your collection and praise, which is my greatest encouragement. Source Code <?php /** * TODO:Database Model Class * Author: entner * time: 2017-5-6 * version:1.0 */ Class DB{ protected $HOST = '127.0.0.1'; //Host address protected $DATABASE; protected $USER ="root"; //Database us ...

  Following the article on July 31, 2018: vim /lib/systemd/system/nginx.service   [Service]Restart=alwaysRestartSec=1Type=forkingPIDFile=/run/nginx.pid    systemctl daemon-reload systemctl start nginx After kill ing, the nginx will be automatically restarted. ------------------------------------------ If the original link is valid, ...

Before PHP 5.4, the way PHP object-oriented needed to reuse code was to use class inheritance. However, PHP only supports single inheritance, and in dealing with more complex business logic, single inheritance is difficult. Use scenarios of trait For example, the following application scenarios: class Person { public function eat() { ...

Operating system: linux Mint 18.2 Compile and install php7.2 1.Install the compiler first sudo apt install gcc automake autoconf libtool g++ #Under centos, it is yum install gcc automake autoconf libtool gcc-c++. 2.Installation of Foundation Library sudo apt install libxml2-dev openssl libssl-dev curl libcurl4-gnutls-dev libjpeg- ...

Chapter 3 HBase Shell operations 3.1 Basic Operations 1. Enter the HBase client command line [lxl@hadoop102 hbase]$ bin/hbase shell   2. View Help Commands hbase(main):001:0> help   3. See which tables are in the current database hbase(main):001:0> list TABLE ...