Programmer Think

Source code analysis jdk1 HashMap under 7 We all know that the bottom layer of hashmap version 1.7 is composed of array and linked list. Today, let's analyze the source code ourselves~ It's a little long. I don't talk much nonsense. I'll start the analysis directly~ Attribute declaration //Initialization capacity static final int DE ...

[JavaSE learning notes] JUC toolkit for concurrent programming 1, What is JUC Java. 0 is provided in Java 5.0 util. Concurrent (JUC) package, in which tool classes commonly used in concurrent programming are added to define custom subsystems similar to threads, including thread pool, asynchronous IO and lightweight task framework; Collect ...

preface Imagine that you are a little white who has just come into contact with the computer. How to learn? Of course, it starts from the Internet. How to make our learning route not yaw. Here is a "shortcut" for you to quickly go to the peak of your life and marry Bai Fumei. From shallow to deep, you will understand Internet re ...

1, First of all, understand the process of CBV in Django. The full name of CBV is Class Base View, and its Chinese name is class view. In short, the use method of CBV in Django is class name as_view() before entering as_ In view (), the dispatch() method will be executed first. In Django's view, the dispatch() method only reflects the url and ...

1. Use arrays Precautions for aslist 1.1 possible pits Let's take a look at arrays Use of aslist: List<Integer> statusList = Arrays.asList(1, 2);System.out.println(statusList);System.out.println(statusList.contains(1));System.out.println(statusList.contains(3)); The output results are shown in the figure below: Then, add element 3 ...

Java simple system monitoring: real-time display of CPU utilization, memory utilization, remaining power of laptop battery and time (hour, minute and second). Create the system tray, set the system tray menu, and display the form on the top. Read battery data by jna calling dll file. catalogue design sketch Function description Projects and ...

In tutorial 1, we generated a working stub project, but we didn't write any code ourselves. Let's see what's generated for us. What happened In the src/helloworld directory, you should see three files__ init__.py: __ main__.py and app py. __ init__.py marks the directory helloworld as an importable Python module. It is an empty file; The fac ...

Background: This is in CentOS 7 6, but this problem actually exists in many kernel versions. How to do a good job in monitoring and controlling some linux caches has always been a hot spot in the direction of cloud computing, but these hotspots belong to subdivided scenarios and are difficult to integrate into the main baseline of linux. With t ...

1. Creation and initialization of one-dimensional array 1.1 creation of array An array is a collection of elements of the same type. How to create an array: Array element type array name [constant expression]; eg. int arr[5]; char ch[100]; Error prone point in VS compiler: [] should be a constant expression int n = 5; int arr[n];(×) in ...

1, Generics Genericity is another widely used feature in Java. Genericity means that the parameter type is not fixed, that is, any data type can be used. It also has another name, that is, parametric type - that is, not only the data itself is a parameter, but also the data type can be specified as a parameter - class Interfaces or methods can ...