dwdm basics

Linux basics: Basic users of Linux users. when using Linux, users must run as one user. Users can restrict the resources that users or processes can use or cannot use. Group to facilitate organization and management. each user has a UserID, which is actually used by the operating system... linux basics: Basic users of Linux users. when using Linux, users must run as one user. Users can restrict the resource

Java BASICS (12) IO input and output, java basics io Input and OutputI. IO Overview 1. IO concepts IO: I represents Input; O represents Output. In Java, IO is input and output based on a stream. AllSerializing data(SAVE) write to the output stream or read from the input stream. Note:Serializing dataThe object state is saved to a stream in a specific form (such as byte []) and written in a stream.2. Function

Java BASICS (2) and java Basics 1. absolute path/relative path 1> complete absolute path URL 2> the relative path/starting with "/" indicates the entire web project. 3> relative paths not starting with "/"./indicates the current path./indicates the upper path. Two-thread status New ready for execution blocking death Algorithm Analysis There are n floors of stairs and a maximum of m floors in each step. How

Java basics-String class (1), java basics string class I. StringClass represents a string All character strings in Java (such"abc". Strings are constants, and their values cannot be changed after creation. The string buffer supports variable strings. Because the String object is unchangeable, it can be shared. For example: 1 String str = "abc "; It is equivalent: 1 char data [] = {'A', 'B', 'C'}; 2 String

Maven basics and maven Basics 1. Introduction to maven Maven is an open-source project of the Apache organization. It is a construction tool for a project. 2. Advantages of maven Maven is not only a building tool, but also a dependency management tool and project management tool. It provides a central repository to help us automatically download components. To solve problems such as increasing depende

[Java Basics] 14. bitwise operations-bitwise AND () operations-(fast modulo algorithm) and java Basics 14 Operations The redis dictionary structure is learned. The hash Value sizemask operation is used when the hash is used to find the index value of the slot,The subsequent scan operations involve the scanning sequence logic. The slots in the same model are scanned according to certain rules!It involves th

Php object-oriented BASICS (3) and php object-oriented Basics 1. Static *Common Member: belongs to the objectStatic member: belongs to the classKeyword: staticClass FenBi{Public $ length = 10; // chalk length, common memberPublic static $ color = "red"; // chalk color, static memberPublic static function test (){Echo "static member method". self: $ color; // self class, which can also be implemented using t

Java basics 1 Environment configuration, java basics 1 1. Download JDK: http://www.oracle.com/technetwork/java/javase/downloads/index.html 2. Install JDK: Click Next to complete. Note: The default installation path is C: \ Program Files \ Java. to customize the path, place the JDK and JRE paths in the same path with the same drive letter. For example, D: \ Java \ jdk1.7.0 _ 17, D: \ Java \ jre7 3. JDK Co

Chapter 1 spring basics and chapter 1 spring Basics Since the company developed and used spring boot, it began to learn spring boot. This series is mainly based on spring boot practices. 1.1 set up the spring environment and configure maven as follows: (2) Use @ Service to introduce the spring container object class to the container, and @ Autowired automatically injects the object.View Code(3) Main config

Java BASICS (10) and Java BASICS (I. Data Structure 1. Definition of Data Structure Data structures are stored by computers and organized by data. A Data Structure refers to a set of data elements with one or more specific relationships between each other. Generally, a well-selected data structure can improve the running or storage efficiency. Data structures are often related to efficient search algorithms

Java concurrency BASICS (I) -- Thread, java concurrency basics thread Concurrent Programming allows us to divide programs into multiple separate and independent tasks. With the multi-thread mechanism, these independent tasks will be driven by the execution thread. When a thread is used, the CPU will take turns to allocate time to each task. Each task feels that it is occupying the CPU. However, the CPU time

Spring basics-automated bean assembly and spring basics bean As mentioned in the previous blog post about Spring's IOC container, although the container is powerful, the container itself is just an empty shell. We need to take the initiative to put the Assembly object and tell it the collaboration relationship between objects, then the container can use its magic as instructed to complete bean assembly's mi

JAVA basics ---- continuous updates, java basics ----1. basic Data Type-integer: byte short int long, which is converted to the floating point type when int is used by default. float double is double-boolean by default. the reference types include arrays and classes. The interface type references object = new Constructor (), Person p = new Person (), and Person as a reference type. 3. function or method-met

Java basics-GUI programming (1), java basics gui Programming I. Definition The full name of GUI is Graphical User Interface, that is, Graphical User Interface. JDK provides two packages, AWT and Swing, for GUI program design and development. 1. java. awt abstract Window Toolkit (abstract Window Toolkit), which is an early version of java and has a limited variety of components. It needs to call local system

Java basics-I/O (2), java basics I/O Next, take the study notes. I/O learning, I suddenly found some advantages, as if to operate the computer in the future, especially the files in the computer, you can rarely use the mouse. You can add, modify, or delete a few lines of code. This is just a little bit of my mind for beginners. I believe there are many other things behind IO. Continue Learning ing .... I. B

Python BASICS (day1) and python basics day1 I. Differences between py2 and py3 The biggest difference is that py3 supports Unicode. Official support for py2.7 will be suspended on March 13, 2020 One popular module that don't yet support Python 3 is Twisted (for networking and other applications ). Ii. Hello World Program Create a file named hello. py in linux and enter 1 print("Hello World!")View Code Then

[Java Basics] Singleton mode, java Basics Singleton mode: ensure that one or only one object exists during the entire project operation. Mainly include: 1, hunger, 2, lazy. 1 class Singleton1 // 2 {3 private Singleton1 () {}// privatize the constructor first, the external creation object 4 private static final Singleton1 instance = new Singleton1 () is not allowed; 5/* The hungry Chinese expression is assig

Python basics-using Mysql and python Basics Python is very convenient to operate Mysql. The basic operations of MySQLdb are as follows: Query: 1 try: 2 conn = MySQLdb.connect(host=self.ip, user=self.username,passwd=self.password, db=self.dbname, port=self.port) 3 cur = conn.cursor() 4 cur.execute(sql) 5 rows = cur.fetchall() 6 data = rows 7 except MySQLdb.Error, e: 8 print str(e) 9

Python mail basics and python Basics Python is not very convenient to operate emails. To tell the truth, it is not very thorough. I want to summarize what I have encountered this time. The email includes the imap, pop, and imap protocols. This time, we use the imap4 protocol and the mail class, The Code mainly references The main code is as follows: Initialize and define the email server self.IMAP_SERVER='

Python django BASICS (1) and pythondjango Basics Django introduction:Django is an open-source Web application framework written in Python. It adopts the MVC framework model, namely Model M, view V and controller C. However, in actual use of Django, Django focuses more on models, templates, and Views, which are called the MTV mode. The main purpose of Django is to develop a database-driven website easily and