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
, we briefly introduce Linkedhashset, which is a subclass of HashSet, but uses linkedhashmap internally.If you need a map implementation class, and the type of the key is an enumeration type, you can use HashMap, but you should use a dedicated implementation class Enummap, why? Let's discuss it in the next section.----------------To be continued, check out the latest articles, please pay attention to the public number "old Horse Programming" (Scan the QR code below), from the introduction to adv
expression is not used. (Execution efficiency is not necessarily high compared to other algorithms, and is only used to verify that the program's processing power is enhanced through rules, and that the regular expressions and program logic are not rigorously written without deep validation due to no in-depth testing)In fact, although the program is very simple, but, in fact, is a simple rule of the prototype engine.First, he loads a lot of business processing rules, plus, minus, multiply, divi
rule of the prototype engine.First, he loads a lot of business processing rules, plus, minus, multiply, divide, interpolate, index, remainder and so on.Second, his business rules can be extended continuously.Thirdly, as long as the facts are given, finally, by the constant application of the rules, he will eventually export the result, either the correct result or the fact that it is wrong.For children who need the source code, please go to git and get the codes directly.Git address: http://git
The system has become extremely difficult recently.QQ landing on the card, NetEase cloud music into not go, cool dog card dead, iOS simulator card dead ...All kinds of perverted cards dieCheck all over the network, call customer service, clear cache, re-install the system still no solution?????Half a month, it's torture.When I was about to give up my Mac, I looked at Performance Monitor and found that the programs that were stuck were all needed for a
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 Completion
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
The MySQL service on the local computer is stopped after it is started. Some services will be automated when they are not used by other services or programs, and other mysql services
Re-install the MySQL database. Due to the sloppy installation, all the way to next (in fact, strict configuration is required in some places and I forgot to pay attention to it), it is a lot of trouble now.
Error message:
Th
We often encounter open application prompts "Do you want to allow the following programs to make changes to this computer?" "If we do not like this much, then how to close the tip of the tube, specifically as follows."
1. Right-click the Start menu, as follows.2. Click on the "Control Panel" option to enter the Control Panel management.3. Click on the "User account and Home security" option, as shown below
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 (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 (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 (53), thinking 53
The previous sections introduced various specific container classes and abstract container classes. As we mentioned above, Java has a collection class that provides many common functions for container interfaces, these functions are provided in static mode.
What functions are available? There are two possible types:
For the first type, operations can be
Part 2: Full BIOS ManualI. Award bios settings Manual Award BIOS is a type of BIOS widely used on compatible computers. However, the information in Award BIOS is in English and requires a deep understanding of relevant professional knowledge, therefore, it is difficult to set up some users. If the information is improperly set, the performance of the entire computer host will be greatly affected. The following describes the meanings and methods of se
We know that there are two types of BIOS passwords: User Password and system password. The former is used only when BIOS is set, and the latter is required before self-check. The following describes how to clear the user password. Because the system password is cleared, only two methods are available now .. first, of course, it is discharged. Second, it is to find the default password of the manufacturer .... (I will also mention it below ). 1. The most common and simplest method-Debug MethodI
Tools such as VNC and Microsoft Remote Desktop Protocol (RDP) can easily log on to and manage remote computers from your home or office. If you manage multiple different computers or often find multiple remote connections open at the same time, merge and manage and run the remote connection open source project terminals. When you start a remote connection from a terminal, it is displayed in the new tab on the terminal user interface. This terminalProgramSimplify multiple remote connections in a
Thinking logic of computer programs (58) and thinking 58
In the previous section, we introduced how to process files in byte streams. we mentioned that for text files, byte streams do not have the encoding concept and cannot be processed by row, which is inconvenient to use, it is more suitable to use the streaming. This section describes the streaming.
First, we will briefly introduce the basic concepts of
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