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from Destpos to Destpos+length-1. Because it is a native method, it is not visible in the JDK, but you can view the source code in the OPENJDK. The function actually eventually calls the C language's memmove () function, so it can guarantee the correct copying and movement of elements within the same array, which is much more efficient than the general method of replication, and is well suited for batch pr

operation 16 . Database restore : Historical backup record, restore database or single table, statistics backup time and file size 17 . SQL Editor: Powerful SQL Editor, support edit Statement complex query statement, generate dynamic report, can export Excel 18 . Access records: Log each IP access time, source region, network operator, count the number of visits per IP and verbose time 19 . IP blacklist: Blocked IP blocked access to Web site

Java Open source Fresh e-commerce platform-user table design (source code can be downloaded)Note: Since this system belongs to the business-to-business platform, does not design to business-to-consumer architecture.Role analysis: Buyers and sellers.Because the buyer and the seller fill in the information is different,

Java Open source Fresh e-commerce platform-system architecture and technology selection (source code can be downloaded)1. Hardware environmentCompany servers2. Software Environment 2.1 operating systemLinux CentOS 6.8 Series2.2 Reverse Proxy/web ServerNginx2.3 Application Serverjdk7+ Tomcat 72.4 DatabaseMysql 5.6.x2.5

. Loadfractor plays the role of a flag bit, which marks the beginning and end of the calculation. About the H + + Entry.hashcode () in the H will overflow problem, above the hash () function has seen each time the hash will be with the 0x7fffffff, that is, the hash is always positive, will not overflowSerialization and deserializationprivate void WriteObject (Java.io.ObjectOutputStream s) throws IOException {entryNote that during deserialization, it does not recreate a hashtable that is exactly

the data on the server. The specific process is as follows: Client requests a protected resource for the server The server sends a request to the client to request username and password. Client sends user name and password to server The server returns the appropriate data to the client This authentication method is not secure, the client sends the user name and password is Base64 form encrypted text, this situation of the user name and password is exposed, if someone c

26. Map points to obtain latitude and longitude coordinates, based on the two latitude and longitude calculation distance27.tab label page function, tag free switch, not duplicate operation database28. In-Station letter voice alert, JS control audio playback29. Baidu Rich Text editor, can upload pictures30. Web crawler technology, can be based on the Web site to crawl pictures and page titles and other information (crawl a store image to save the server)get "" qq:313596790 "Free support Updates"

expansion of the original twice times.Iteratorsprivate abstract class HashIteratorIn fact, the implementation of the iterator in the collection implementation of the class are similar, as long as you see one on it. This also records the number of changes expectedmodcount, that is, after the iterator is created, it is not possible to iterate during the modecount++ such operations, or appear fail-fastSerialization and deserialization-saving and reading the state of HashMapprivate void WriteObject

memory, will not cause fragmentation.Selection of arrays and linked listsFrom the above analysis, the difference between the array and the linked list affects us the most: The array is quickly found by location, and the linked list is easy to delete Arrays are fixed size and linked lists can be expanded and scaled down at any time Linked list each element occupies slightly more memory than the array Arrays and linked lists are generally more common in queries, and take a lo

In the previous article, detailed description of the source code of HashMap and HashSet, from the point of view of the source can be seen in the depth of the relationship between the two, speculation, Linkedhashmap and Linkedhashset must also have in-depth contact. After analysis you will find that the relationship between the two is the same as HashMap and HashS

successfully. If the Java command does not execute successfully, add an entry in path (add a new item after the value of the previous path), as follows: D:/program files/java/jdk1.6.0_17 If the Javac command does not execute successfully, add another entry in path, as follows: D:/program Files/java/jdk1.6.0_17/bin The

The difference between the source code, the reverse code, and the supplementary code in Java >>>> and the reverse code. When I analyzed the HashMap hash algorithm two days ago, I met the >>and >> symbols. At that time, I checked t

The problem is: the path to the keyboard input file, find content, and replace content to find and replace the contents of the file for the specified path. ” Long time no write interface, today familiar with the interface of the writing and listener operation. The problem is not very difficult in itself, and the focus should be on the handling of various possible errors during file processing. So write code needs to be very careful, and the error is h

For example, to count the workload of a Java programmer writing code in one day (for example, the number of lines of valid code, the number of blank lines, and the number of lines of comments), this tool may serve as a reference. Idea: because the content of each Java source

;linkedlist,add (e e), because of the existence of node last, O (1), add (int, E), need to traverse the depth of int first, In fact, the increment is the process of re-assignment, not the process of traversal, but also O (1), but actually a round down, also reduced to O (n);Delete: Arraylist,o (n), need to system.arraycopy;linkedlist, only see Delete, O (1), but in any case can not ignore the performance of the search consumption, and eventually reduced to O (n);Change: ArrayList, specify the po

Original: Java Swing development of short and concise Tetris game source code download, only 300 lines of codeSource code: Http://www.zuidaima.com/share/1550463495146496.htmJava Swing development of short and short Tetris game source cod