liminal thinking

Thinking logic of computer programs (59) and thinking 59 The previous two sections show you how to read and write file content through a stream. This section describes operations on file metadata and directories. File and directory operations are ultimately related to the operating system and file system. The implementations of different systems are different, but Java. io. the File class provides a unified

Thinking logic of computer programs (80) and thinking 80 This section describes scheduled tasks. There are many application scenarios for scheduled tasks, such: An alarm program or task reminder. You can call a bed at a specified time or return a credit card on a specified date. The monitoring system collects system data at intervals to trigger alarms for abnormal events. Statistical System, which usual

Thinking logic of computer programs (79), thinking 79 In the previous section, we mentioned that in asynchronous task programs, a common scenario is that the main thread submits multiple asynchronous tasks and then processes the results if a task is completed, in this scenario, Java provides a convenient method for sending and distributing packets. The CompletionService is an interface and its implementatio

Thinking logic of computer programs (78) and thinking 78 In the previous section, we initially discussed the task execution service in Java and package. In reality, the main implementation mechanism of the task execution service is the thread pool. In this section, we will discuss the thread pool. Basic Concepts A thread pool, as its name implies, is a thread pool. There are several threads in it. They are

Thinking logic of computer programs (87) and thinking 87 In the previous section, we discussed dynamic proxies. in the previous sections, we mentioned ClassLoader for many times. This section will discuss in detail the class loading mechanism and ClassLoader in Java. ClassLoader is the Class for loading other classes. It is responsible for loading bytecode files to the memory and creating Class objects. Lik

Thinking logic of computer programs (67) and thinking 67 The previous section introduced the problem of competing multiple threads to access the same resource and the solution synchronized. we mentioned that in addition to competition among multiple threads, mutual collaboration is often required, this section describes the basic mechanism of multi-thread collaboration in Java. What scenarios need collabora

Thinking logic of computer programs (74) and thinking 74 This section describes a commonly used concurrent container-ConcurrentHashMap, which is a concurrent version of HashMap. Compared with HashMap, it has the following features: Concurrency Security Directly supports atomic composite operations Supports high concurrency, fully parallel read operations, and parallel write operations to a certain exten

Thinking logic of computer programs (39) and thinking 39 In the previous section, we introduced the ArrayList. the random access efficiency of ArrayList is very high, but the insertion and deletion performance is relatively low. We mentioned that the List interface's parallel List is also implemented, its features are almost the opposite of that of ArrayList. This section describes the feature list in detai

Thinking logic of computer programs (45) and thinking 45 The previous sections introduced the basic container classes in Java. Each container class has a data structure behind it. ArrayList is a dynamic array, sorted list is a linked list, And HashMap/HashSet is a hash table, treeMap/TreeSet is a red-black tree. This section describes another data structure-heap. Introduce heap We mentioned heap before, whe

Thinking logic of computer programs (49), thinking 49 Previously, we introduced two implementation classes HashMap and TreeMap of the Map interface. This section introduces another implementation class LinkedHashMap. It is a subclass of HashMap, but it can keep the elements sorted by insert or access, which is different from the TreeMap key sorting. It is easy to understand the order by insert. What does th

This is a creation in Article, where the information may have evolved or changed. In many of the application scenarios of the design program we encounter task flows that are broadly divided into three phases. First, entrance One or more entrances, waiting for blocking, or unsolicited requests. ============================== For example, the task flow needs to accept application requests from HTTP and FTP, and subsequent requests for acceptance may be added in other ways. Second, processing Mult

Thinking logic of computer programs (1), thinking LogicWhat is the program? A computer is a machine that consists of CPU, memory, hard disk, and input/output devices. Operating systems run on the computer, such as Windows or Linux, and various applications, such as Word and QQ, run on the operating system. The operating system divides the time into many small time slices. One time slice is used by one progr

Thinking logic of computer programs (30), thinking Logic The previous section introduced the String, and mentioned that if String modification operations are frequent, StringBuilder and StringBuffer classes should be used. The methods of these two classes are basically the same, and their implementation code is almost the same, the only difference is that StringBuffer is thread-safe, while StringBuilder is

Week after week, today is Friday.The programmer's initial article:No matter what new knowledge to learn, or to start a thing, you first have to stand at a height, the overall context, a clear grasp of the outline, know how to go, then, the problem, learning programming it?Yes, the process of learning programming requires a person to have a wide range of knowledge, such as Java engineers, from simple Java APIs to Oracle databases, from simple JS, jquery implementations, to STRUTS2,HIBERNATE4,SPRI

background, database short server, JSP is nested in the Web page. Because different systems have different layers, some three layers, some four layers, some multilayer ...Basic can be divided into: 1. Web page 2. Web server 3. Background, database server 4. DatabaseSummarize today's work: The task today is to do a data deposition, that is, to read the JSON string and then write the data in the JSON string into the database. creat table TableName (F1 char (8), F2 varchar (+) NOT null), using Pls

Thinking in JAVA notes-Chapter 1 Introduction to objects and thinking This chapter introduces the basic concepts and principles of object-oriented 1.1 Abstraction My understanding: Hiding complex and useless attributes, leaving what the program needs 1.2 each object has an Interface Question: The concept of interfaces and implementations and why the interface mechanism is introduced (see the specific chapte

[Thinking in Java] Chapter 7th-reuse classes and reuse of thinking [Code reuse is one of the many notable functions of Java. But to become a revolutionary language, it is not enough to simply copy and change the code. It must be able to do more .] 7.1 combined syntax The combination is to put the object in the new class and make the members of the new class, such class A {}class B { private String value

The boat of life sails to sail, without the oars of wisdom. Stupidity always comes when the tongue runs faster than the mind. Wisdom is a bead, practice is a thread. To make a string of beads, you can't break the line. If there is no evil, resourcefulness becomes a terrible thing. The impulse to lose one's senses often leads to long regrets, and long hatred often leads to the loss of 诮 passions. A wise man does not think he is cleverer than others, and fools always regard his judgment as infalli

Article Description: Agile Experience designers have 5 modes of thinking. We have a Hong Kong designer buddy, the overall wearing culottes, Nike Airforce Collector's Edition, one openings is: full force body (mentality) I intend to turn into thinking mode. What he means is that designers need a different mindset. I'm thinking about the question: what k

1. No mathematical basis for programming2, but understand math does not mean to understand programmingTo give an example:Seek the 1+2+3+4+......+99+100 and.The mathematical solution is usually:1, (1+100) *100/2=55002, the pupil's solution: 1+2=3, 3+3=6 、...... So tired to go on.What about the programming solution? The same as the mathematical solution 2, the code is as follows:Static void Main (string[] args) { int0; for (int1; + +i) { + =