• There are six differences between filter and interceptor. Don’t be so silly


    At the weekend, a little friend added my wechat and asked me a question: brother, what’s the difference between filter and interceptor? My first feeling after hearing the title is: simple! After all, these two tools are used very frequently in the development, and the application is relatively simple. But when I was going to […]

  • C + + basic knowledge conclusion


    On constant member functions: Const double function() and double function() const; many people may confuse them, but they are not exactly the same. The former is to ensure that the returned value is the constant (Note: variable cannot be changed), the latter is to require that your function does not involve changing the value of […]

  • Sorting algorithm 04


    1. Merge and sort The idea of merge sort is divide and conquer. In short, it is to divide a sequence to be sorted continuously, and finally get an ordered sequence (the sequence with only one element is an ordered sequence). Then these ordered sequences are merged. The first merge will merge the ordered subsequences […]

  • The use of Yii redis Zset ordered set


      Similar to hash which stores the mapping relationship between key and value, ordered set also stores the mapping between member and score, and provides score processing commands, as well as commands to fetch and scan member and score in order according to score. Here are some common commands and their use in Yii. ZADD […]

  • Data () {..} returns an object or does not return an object


    Write one, return an object data() { return { req: {} }} Write method 2, do not return the object, directly mount to this data() { this.req= {} } The above two methods can get req objects, but the differences at least include:1. The req obtained by writing method 1 is responsive, while the req […]

  • [data structure] – find the access order of a node in binary tree in preorder, middle order and postorder traversal


    Title Requirements Let the binary tree adopt the binary linked list storage structure, and the node data field be character type. Write a program to establish the binary list storage structure of binary tree by using the pre order recursive method. Then input a character and output the access order of the character in the […]

  • Detailed explanation of @ postconstruct annotation in spring framework


    Author: spring rolls should be fried https://www.jianshu.com/p/dee681eb3e86 2020-02-12 11:12:00 In spring projects, we often [email protected] First of all, we introduce its purpose: annotated methods are executed after the dependency injection of the object is loaded. This annotation is added to the Java ee5 specification and plays a certain role in the servlet life cycle. It […]

  • How to control the loading order of beans in springboot


    1. Why do you need to control the loading order springbootAccording to the principle that the agreement is greater than the configuration, the problem of complicated configuration is solved to a great extent. On this basis, it also provides the SPI mechanism, using thespring.factoriesIt can complete the automatic assembly function of a small component. In […]

  • Leetcode 215. The kth largest element in the array | Python


    215. The kth largest element in the array Title Source: leetcode https://leetcode-cn.com/problems/kth-largest-element-in-an-array subject The kth largest element was found in the unordered array. Please note that what you need to look for is the kth largest element after sorting the array, not the kth different element. Example 1: Input: [3,2,1,5,6,4] and K = 2 Output: […]

  • Redis real combat — 12. Reduce memory consumption


    brief introduction Reducing the memory consumption of redis helps to reduce the time required to create and load snapshots, improve the efficiency of loading AOF files and rewriting AOF files, and shorten the time required for synchronization from the server (snapshot and AOF file rewriting are introduced in persistence options, from server synchronization to replication, […]

  • 020_ Java process control


    catalog Java process control Scanner object The scanner class is used to get user input java.util.Scanner Jdk5 next() nextLine() nextInt() nextDouble() Sequential structure Selection structure If single choice structure If double selection structure If multiple choice structure Nested if structure Switch multiple choice structure Cyclic structure while Loop Dead cycle Do… While loop The difference […]

  • Data structure and algorithm — sorting


    First, a comparison chart of each sorting algorithm(focus) 1. Bubble sort Idea: bubble sort is a simple sort, which continuously accesses the whole sequence from the beginning,If the current element is larger than the next, swapIn this way, the largest element in the current unordered sequence can be found and put to the end in […]