using preseed

Using Redis for seckilling and throttling, and using redis for thinkingI have talked about seckilling and throttling in the group recently. I have never done similar applications, but I have encountered more data and concurrency at work. Therefore, a simple model is proposed: Var count = rds. inc (key ); If (count> 1000) throw "already available! " Using the Redi

[Spring] Send emails using Spring and send emails using spring The core of Spring Email abstraction is the MailSender interface. The MailSender can be connected to the Email server to implement the mail sending function, such: The implementation of a MailSender in Spring is JavaMailSenderImpl, which also uses the JavaMail API to send an Email. before using it, y

Original: upload more than 30M files using swfupload, upload components using flashA period of time members of the upload components to use flash swfupload to upload, can be very friendly to display the upload progress, but also fully meet the large file Upload.Later server upgrade to Windows 2008, after changing to IIS7, upload files once more than 30M, there will be 404 errors, and is the upload progress

When I see the CPU time of I/O waiting time is very high, the first thing to check is whether the machine is using a lot of swap space, because the speed of hard disk operation is much lower than RAM. So when the system is running out of memory, start using swap space. The performance of the system can be severely impacted.No matter what you want to access the hard disk operation is finished with the hard d

Forwarding requests using the forward () method of the Requestdispatche R and using HttpServletResponse's Sendredirect () method redirection can make the page go to another page, and now collect the difference between the two:I. Requestdispatcher.forward () methodForward is the server requests the resource, the server directly accesses the URL of the destination address, reads the response content of that U

In Java, it is better to save a password using a character array than to save the password using string.Two reasons: It is difficult to purge from memory.String is a non-mutable object that is placed in a string buffer to facilitate reuse, so it may be retained in memory for a long time.Any person with access to the memory can easily see the plaintext passwordOf course, the plaintext password should n

Example 1: void F () {} int main () { using functionptr = void (*) ();///equivalent to typedef void (*FUNCTIONPTR) (); FunctionPtr ptr = f; }Example 2: typedef unsigned char U1; typedef unsigned short U2; Using U4 = uint32_t; Using U8 = uint64_t; Example 3: Using Line_no = std::vectorEquivalent to

the difference between using the left, right, full, and inner joins and using the Where condition statementFrom learning the SQL statement to the present, never used the left and right connection, perhaps someone would be surprised, but it is not, because I have been using the WHERE condition statement. I also want to try the effect, I did a test today, and final

I. Xshell using XFTP to transfer filesClick the Submit button will send you to fill out the mailbox sent an e-mail, which has the download address, click Download xftp-6.0.0085.exe file, download the completion of the installation, after the installation is complete, first switch off, in the Xshell login to their own virtual machine, and then in Xshell press Ctrl+alt +f, it will automatically pop out the following interface just installedDouble-click

Tags: sync digital var size each note MySQL Strong nameFirst, Trigger 1. Triggers are stored in the database as separate objects,2. Triggers do not need to be called, it is triggered by an event to run3. Triggers cannot receive parameters 　　--Application of TriggerFor example: Xiaonei, Happy Net, Facebook, when you send a log, automatically notify your friends, in fact, when you add a log to do a start, and then write entries to the table. 　　--Trigger efficiency is highExample: forum posts, each

Tags: 14 weeks three lessons (March 28)15.4 Xshell using XFTP to transfer filesGo to the page after the download is complete, install and then connect.Both sides can transfer files to each other.15.5 using PURE-FTPD to build FTP serviceVim/etc/pure-ftpd/pure-ftpd.confCheck the process with Port 21Useradd ftp_usera Create user Ftp_usera,-u pure-ftp Specify System user pure-ftp, specify directory-d/data/ftpPU

The back end also has a Java user object class that serializes the user object in the list into XML data using the XStream component. obtained using the E4X format format on the flex side via Httpservice. Just started to parse XML by E4X technology, and construct flex user object, similar to the way it was handled: Copy Code code as follows: Public Function FromXml (currentnode:xml): void{

In the case where the route has been set, take table as an example, can be set as follows, the scope of the corresponding template;App.tableview = Em.View.extend ({}); App.tableindexview = Em.View.extend ({});Can also be created by the following new, its obtained this is the template of this;{{#view Innerview}} ... {{/view}} Innerview = Ember.View.extend ({});Simple settings: Set the overall label: TagName Set class: Classnames:[] (suitable for fixed val

I found a network with the oxygen control to send SMS C # source code, try to debug a bit, found really good, and easy to use. But the drawback is that in the text message will automatically add control company information, registration will cancel this information, but the registration needs a small amount of money. I downloaded the free PC connectivity SDK3.0 directly on Nokia's website and found that it could achieve the same function after debugging. The following program is successful in se

15.4 Xshell using XFTP to transfer files Download xftp software Installing XFTP Software Connecting to an FTP server Just start running and shut down the XFTP software. You need to log in to Xshell 5 first. Turn on Ctrl + Alt + F key combinations to automatically correlate Xftp software. 15.5 using PURE-FTPD to build FTP serviceIn the construction of FTP se

Problem:This case requires the use of Apach DBCP to connect the data pool refactoring class dbutility to the Connectionsource class, refactoring the case "implement Dbutility", providing access to the connection, closing the function " The Empdao class in which you use Connectionsource to obtain a connection.Scheme:When accessing a database directly using JDBC, you need to avoid the pitfalls:1. Every data operation request is a step to establish a

Xshell Transferring files using xftp1. Exit the current session in Xshell using the key combination: Ctrl+alt+f, the following appears:650) this.width=650; "Src=" Https://s3.51cto.com/oss/201711/20/5d402de965f507d85c9ed8d66e662144.png-wh_500x0-wm_3 -wmp_4-s_533607507.png "title=" 1.png "alt=" 5d402de965f507d85c9ed8d66e662144.png-wh_ "/>2, download xftp completed and then press ctrl+alt+f, you can download a

By-page and by-page sorting, using skip and Take, and using linqskip Dbconn. bidRecord. orderBy (p => p. bid_id ). toList The above is the paging sorting method. Let's talk about what to do. Dbconn is the Modle object BidRecord is an entity P => p. bid_id is the sorting condition. OrderBy is sorting (followed by conditions), and then you need to query all the data. In all the data, you need to query the da

Notes for using jqGrid and jquery Datatables on the server page using ASP. net mvc + EF, jqgridjquery Introduction: I want to publish my blog website. The technical route is ASN. NET MVC5 + EF6 (Code First) + ZUI + various Jquery plug-ins. With this idea, I began to select the UI. After reading a lot of bootstrap templates, I found that even if you use bootstrap, you still need to write css styles by yours

stream implemented on a running loop.Checklist 6-1 using the Cfnetdiagnostics API when a stream error occursCase kcfstreameventerroroccurred: cfnetdiagnosticref diagref = cfnetdiagnosticcreatewithstreams (NULL, Stream, NULL); (void) Cfnetdiagnosticdiagnoseprobleminteractively (diagref); Cfstreamerror error = Cfreadstreamgeterror (stream); ReportError (error); Cfreadstreamclose (stream); Cfrelease (