what is liferay

Patterns and frameworks are everywhere in software design. A friend once asked me what is the mode? I am also studying and give the following summary about my learning experience. (Note: personal opinions are for reference only. please correct me .) 1. What is the mode?Pattern. It

1. What is the mode? Pattern. It is actually a methodology for solving a certain type of problems. You sum up the methods for solving a certain type of problems to the theoretical level, that is, the mode. Alexander's classic definition is that each mode describes a prob

for reconstruction. Do not refactor the code that you do not intend to change or will not change. Scratch Refactoring) Michael Feather's "Working processing tively with Legacy Code" book mentions the concept of Scratch Refactoring. Martin Fowler calls it "Refactoring for understanding ". This is used to deal with the (or intolerable) code that you don't understand and clean it up so that before you actually want to modify it, you can have a better un

There is no doubt that the Linux kernel needs to manage all the hardware devices connected to the computer. If you want to manage these devices, you need to communicate with them first, there are generally two scenarios for this functionality:1. Polling (polling) allows the kernel to periodically query the status of the device, and then make the corresponding processing;2. Interrupt (interrupt) allows the hardware to signal to the kernel when needed (

What is a data warehouse, and what is the difference between a databaseDataWarehouseis a subject-oriented (Subject oriented), integrated (integrate), A relatively stable (non-volatile), data collection that reflects historical changes (timeVariant) to support management decisions. (1) topic-oriented: Index data in the

What is the knowledge of this function in PHP and what is its function? The following function has never been used. First, what is PHP knowledge? File processing? Or binary? Second, note it from the beginning to the end. Why have

From: http://www.360doc.com/content/11/0628/21/1330004_130212218.shtml On many download points, in addition to the format of the table after the video, it will also be marked as tvrip, ts, etc. What do these mean? Through the following content, you can simply understand them. 1. Cam (GUN) Edition Cam uses digital cameras to steal videos from cinemas ". Because the camera is often jitters during the video p

Index introduced by the databaseThe most frequently performed operations on the databaseData Query. In general, the database needs to search the entire table for data during the query operation. When a table contains a large amount of data, it takes a long time to search for the data, which leads to a waste of server resources. To improve data retrieval capabilities, the database introduces an index mechanism. An index metaphorTo some extent, we can regard a database as a book, an index as a bo

What is the use of Redis database? What kind of database is suitable for Redis Rini?

　　What is a VPN? 　　The English full name of the VPN is "virtual private network", translation comes from "The fictitious specialized network". As the name suggests, virtual private network we can understand him as a virtual out of the enterprise internal line. This VPN's English full name is "Virtual private network"

, there are already a lot of related articles on the network, which are not mentioned here, only from the system startup principle. UEFI is more powerful than the BIOS because UEFI itself is already the equivalent of a micro operating system, and its convenience is:First, UEFI already has file system support, it can directly read the files in the FAT partition;

The CSR is the abbreviation for cerificate Signing request, which is the certificate requests file. We want to prove that our site is trustworthy, data transmission is encrypted, we need to be issued by a third-party CA agency certificate to prove, such as Symantec,geotrust and so on.To apply for such a certificate, ou

(child process). The Web server sends CGI environment variables and standard input to the FASTCGI child process php-cgi.(3)FastCGI the standard output and error information from the same connection back to the Web server (Nginx) after the child process finishes processing.When the fastcgi child process closes the connection, the request tells the processing to complete. The fastcgi child process then waits and processes the next connection from the FASTCGI process manager. In general CGI mode,

own synchronization to prevent simultaneous access from multiple threads from Causing a race condition. Calls to the MTA object from a thread in an STA is also marshalled. Dynamically determined Apartment (threadingmodel=Both) In the Both apartment mode, the server auto-selects STA or MTA at object creation to match the apartment type of The calling thread. This can is useful to avoid ma

CDN is believed that many friends are not unfamiliar, the Internet also often see related reports. A period of time before the major CDN service provider response to the Prime Minister call, CDN also speed down the cost, like a Web-host CDN, Aliyun CDN have a large price range. Many small white friends have such a question: What is the CDN?

Statement: This is Liuguan Teacher's work "design affairs" of personal reading notes, I write this article is mainly convenient after their own temperature.Don't forget, look at Lugard. Colani's design concept and his work, as well as the German functionalist design representative-Dieter Rams and his esteemed "Webi-sabi".First, what

machine can be normal browsing, and the page uploaded to the server will always appear to see no pictures, CSS stylesheet failure and other errors. This is mostly because you use the wrong path and use an absolute path where the relative path should be used, causing the browser to not open the specified file in the specified location. Let's talk about the difference between the relative path and the absolute path that make the beginner headache.

, and defines the action between objects, which is what can be done, so this is more suitable for developing large programsBut any tool is a double-edged sword (a chopper can kill or cut a dish)To understand programming, you have to understand variablesVariable (changing amount): I