d d expansions

/b.log.② tilde Extension: extended to home directory. such as the root user under the ~/.ssh extension to/root/.ssh.③ variable extension: The value of the action and substitution variables. Replace $ A with its value 24,${name:-longshuai} with Longshuai.④ command substitution: This procedure executes the command in command substitution and replaces the result with the corresponding location of the token.⑤ process substitution: Replaces the execution result of the process with the corresponding l

5 days to change the account expires, that is, in the 5 days of time to cover the user can also set the password, but after the account expires, can not operate, can only be operated by the administrator.Account Expiration days: This is empty, which indicates the number of days from 1970-1-1 to the date the account expires, and the account expires after that number of days.The last one is also empty, which indicates reserved bits, which are reserved for later

command inside the {} brackets only affects the command, but redirects outside the brackets affect all the commands in the parenthesesTwo brackets (()), which represent arithmetic expansions, are standard arithmetic calculations for what they include-note that floating-point numbers cannot be counted, and if a floating-point number is required, it needs to be done in BC.As for the brackets [], the sensory function is used to compare. For example, in

will call some template (JSP)To render the page, after which the Interceptor (Interceptor N) responds to the last response (the reverse of the order and the Action Execution) (HttpServletResponse) The filters and (core controllers) (Filterdispatcher) configured in Web. XML are returned.6. Why use struts?First, Struts is an implementation of MVC, which uses servlets and JSP tags (which belong to the Java EE Specification) as part of the implementation. Struts inherits the characteristics of MVC

the mistake I made on Java startup parameters. Java.lang.OutOfMemoryError:Map failed Vi. specifying container initialization sizeOne of the features of the Java container is the ability to dynamically expand, so usually we do not think about the initial size of the setting, not enough will be automatically expanded chant anyway.But expansion does not mean there is no cost, even a high price.For example, some array-based data structures, such as StringBuilder, StringBuffer, ArrayList, H

The principles and advantages of struts.How Struts WorksMVC is the abbreviation of Model-view-controller, which is a common design pattern. MVC weakens the coupling between the business logic interface and the data interface, and makes the view layer more varied. How MVC works, as shown in 1:Struts is an implementation of MVC, which uses servlets and JSP tags (which belong to the Java EE Specification) as part of the implementation. Struts inherits the characteristics of MVC and makes correspond

necessary, double the expansion @Override Public V-Put (K key, V value) { if (key = = null) {return Putvaluefornullkey (value); } Some code here //No entry for (Non-null) key is present; create one modcount++; if (size++ > Threshold) { tab = doublecapacity (); Index = hash (tab.length-1); } Addnewentry (key, value, hash, index); return null; } There are usually several ways to expand the problem. 1. Estimate a large capacit

1. The PDO (PHP Data Object) extension defines a lightweight, persistent interface for PHP to access the database. Each database driver that implements the PDO interface can display its own features in the form of regular expansions. Main: PDO extension is only an abstract interface layer, the use of PDO extension itself can not achieve any database operations, must use a specific database PDO drive access to the database 2, Start PDO method : Find

-close (closed for modification) principle, as well as the extended openness (open for extension) principle, the invariant parts of the software system should be abstracted, in the object-oriented design,-These invariant parts can be abstracted into invariant interfaces that can be used to deal with future expansions;-Minimum functional design principles for interfaces. According to this principle, the original interface can either deal with future ex

) Oracle RAC: The biggest feature of its architecture is the shared storage architecture (Shared-storage), where the entire RAC cluster is built on a shared storage device, with high-speed network interconnection between nodes. Oraclerac provides very good high-availability features, such as load balancing and application transparent dice (TAF), with the greatest advantage of being fully transparent to applications and switching to a RAC cluster without modification. But the scalability of RAC i

capacity for upgrades and expansions; From the product, the requirements can be from the use point of view, with more close to the actual user, easier to manage and maintain products Finally, some auxiliary means, such as electronic distribution frame, electronic label management system, can be used to help manage the cabling system of the data center. Good cabling management can effectively reduce maintenance time and reduce the likelihood of errors

. Sometimes when deploying a device, the enterprise may overlook the business factor due to the detailed technical requirements of the Data Warehouse project. In addition to identifying hasty business problems and requirements for data Warehouse devices, the performer should look at the data-related business rules in the Data warehouse, trying to calculate the project's return on investment and the total cost of ownership of the new schema/expansion architecture. ROI and TCO charts help to deter

> Proplists:property ({A, false}).{A,false}2> Proplists:property ({A, true}).ANote: The other is to simplify the representation of {Key::atom (), true} tuple as Key. Other tuple Forms Invariant 1.11 compact (listin)-> List 1> Proplists:compact ([A, {A, true}, {A, 1}, {1, a}, {1, true}]).[A,a,{a,1},{1,a},{1,true}]Note: equivalent to [Property (P) | | P Expansions:[{property::p roperty (), Expansion::[term ()]}]NOTES: This is a substitution operation.

key hash value found in the array position, and traverse the location of the list, find the key value of the same entry. The list in the HashMap consists of the entry class, entry contains three elements: Key,value and Next (refers to the down one entry), and the list in the HashMap adds a new entry, which is placed in the head position of the list, The new entry next element points to the original entry in the head of the list. Do you know how HashMap works? HashMap the hash algorithm to deter

Fluke Network tester and the network monitoring function to simulate the load flow of the network and test its response. 10 or seven-layer flow statistic analysis For statistical analysis of the flow rate of each layer, the application of seven layers can be statistically and analyzed by using the analysis instrument of Fokker Network or protocol analyzer and Flow Analyzer. When your network has passed these tests, you will not only be assured of running now, but you will also be able to qui

on it2) Adjust the innodb_autoextend_increment configuration to 128M due to the default 8MThe main purpose of this configuration item is that when the tablespace space is full, there is a need for the MySQL system to automatically expand how much space, each time the tablespace extension will let each SQL wait state. Increasing the auto-scaling size reduces the number of tablespace auto-expansions.3) Adjust the innodb_log_buffer_size configuration to

(), Field.getdecimal ());}System.out.println ();for (int i = 0; i Dbfreader.next ();For (Field Field:dbfReader.getFields ()) {System.out.printf ("%" + field.getlength () + "s", Field.getstringvalue ());}System.out.println ();}Dbfreader.close ();}} You can see that the final use is also very concise.Code Statistics085959_ezqv_1245989.jpg (15.06 KB, download number: 0)Download attachmentsUploaded 6 days agoThe total number of lines of code is 282 lines, minus import and interface declarat

Field:dbfReader.getFields ()) {System.out.printf ("name:%s%s (%d,%d) \ n", Field.getname (), Field.get Type (), Field.getlength (), Field.getdecimal ()); } System.out.println (); for (int i = 0; i you can see that the final use is also very concise. Code Statistics 085959_ezqv_1245989.jpg (15.06 KB, download number: 0)Download attachments2015-5-27 22:33 UploadThe total number of lines of code is 282 lines, minus import and interface declarations, and so on, the rea

Regular Expressions (regular Express)The expression of a rule, which is to represent data with the same characteristics with some pre-defined symbols, almost all programming languages use regular expressions (regular) and are common in different programming languages.Regular pointsStandard Regular、Extended Regular, the extension is more simple and flexible to make some modifications and expansions in the basic regular rules, while the few parts only s

adding/deleting elements to/from the list to demonstrate the effects of different interactive animations. Demo 1 does not perform any processing. It is both raw and rough and cannot give people any natural feeling.In Demo 2, some key frames are added to make the added actions much smoother. Such an animation can give you some hints.The last demo is the most natural fit. Just as we usually insert a book into the bookshelf, we need to free up space before inserting/removing it. For example, the