Tag:Star pool

  • C++ learning method guide for pointers


    If all unused pointers are given null values and null pointers are avoided, misuse of an uninitialized pointer can be prevented. Many times, uninitialized variables have some garbage values, which makes the program difficult to debug.StarpoolThe compiler does not know which function to call. Therefore, c++ defines null as (int) 0, which solves the matching […]

  • Document guidance for carry4 principle analysis


    An XOR operation is performed (implemented by LUT lookup table, XOR is addition without carry).StarpoolThe data has been added before entering carry4, but the carry flag has not been determined. From this view, I can understand the principle and process of carry4. If the corresponding bit is 1, add, otherwise shift to the right. Note […]

  • Is there an integration method case for springboot


    Some basic uses of dozer are summarized. Dozer supports annotation, API and XML Mapping configurations,Star pool digging serverThe XML method is commonly used. The XML Mapping configuration method used earlier is also used. The map ID attribute of the mapping element in the XML Mapping configuration can set the ID of the mapping, which determines […]

  • Children form a circle and assume an arbitrary number M


    Start with the first child and circle one by one. The idea is to first add the first child, then add one child, and follow the front child. When adding one child after the last child,StarpoolIt is very important to add the pointer position before and change the operation sequence of the pointer, which should […]

  • What is the basic principle of iptables and how to build it


    It can be managed through the character management tool firewall config and the graphical management tool firewall config. The configuration in / etc / firewalld / is preferred. If there is no configuration file,StarpoolThe data in the default configuration file / usr / lib / firewalld is used. It has two configuration methods: run-time configuration […]

  • Judge the 0-1 of a and B respectively


    If the upper eight bits are not greater than, it is possible that the second eight bits are still a large. It should have output 1, but 0 is output. This is wrong, so it is necessary to judge whether the upper eight bits are equal to,StarpoolIf equal, continue to judge the last eight digits […]

  • Java file upload example description file


    The implementation of map interface exists in the form of key value storage. The implementation of HashMap is not synchronous,StarpoolThis means that it is not thread safe. Its key and value can be null. In addition, the mapping in HashMap is not orderly. Theoretically, hash conflict means that the calculated hash value is the same, […]

  • Image layered design case of docker container


    There are both CMD and entrypoint commands in, which should be divided into scenarios. If entrypoint uses shell mode, the CMD command will be ignored. If entrypoint uses exec mode, the contents of the CMD command will be appended as the command parameters of entrypoint;StarpoolThe echo test is performed according to the normal request process, […]

  • Function external variable that returns a non integer value


    The extensive use of external variables will lead to a large amount of data exchange between various functions,StarpoolIt will have an adverse impact on the structure of the program. Functions and external variables can be compiled separately. When functions in file1 need to call external variables in File2, external variables in File2 need to be […]

  • Formal learning of for loop structure


    Assign initial value to cyclic variable) “means that no initial value is assigned to cyclic variable. Omit “expression 2 (loop condition)” and do no other processing, and the loop is always executed (dead loop),StarpoolBecause int is an integer, the decimal part will be omitted. For example, the result of 765 / 100 is 7 ten […]

  • How do I add SELinux permissions


    SELinux is a mandatory access control (MAC) system provided in the 2.6 Linux kernel.StarpoolSELinux is the most comprehensive and fully tested Linux security module currently available Yes, it is based on 20 years of MAC research. SELinux combines multi-level security or an optional multi class policy in the type enforcement server, and adopts role-based access […]