Teach yourself Java and find 20k jobs

Hello everyone, my name is Dabin~

My undergraduate degree is not computer science. In my senior year, I started to learn Java by myself and found an offer from Zhongda Factory. I encountered a lot of problems on the way to self-study. Every night, I insisted on going to sleep until one or two o'clock, and finally got an offer of 30w.

I also remind the juniors and juniors to determine their future direction as soon as possible, whether to study for graduate school or work. If you are looking for a job, you should also determine the job position as soon as possible. If you want to change careers, you need to spend more time preparing. Many students only think about what they want to do in the future when they are about to graduate in their senior year, and it is already a bit late at this time. If you miss the school recruitment and go to the social recruitment channel to find a job, the difficulty will increase by a level, and it will be too late to regret it!

Well, let me share with you my self-study experience.

First look at the Java learning roadmap:

There is still a lot of content, and you need to keep persevering!

I would like to share with you a well-organized high-frequency questions PDF 161edfa1cab6dd. The friends who need it can download it by themselves:

http://mp.weixin.qq.com/s?__biz=Mzg2OTY1NzY0MQ==&mid=2247485445&idx=1&sn=1c6e224b9bb3da457f5ee03894493dbc&chksm=ce98f543f9ef7c55325e3bf336607a370935a6c78dbb68cf86e59f5d68f4c51d175365a189f8#rd

Java Basics

The advice for beginners is: more codes! More typing! More typing!

Learning programming is reading books and practicing. You have to do more hands-on, otherwise you will soon forget the knowledge points you have read, and you will encounter many pits and enrich your experience with more practice. You can go to github to find some projects to practice your hands, and consolidate your knowledge by doing projects, and each time you implement a function, you will have a full sense of achievement, and it will also motivate you to keep learning.

Recommended Books:

《head first java》
"JAVA Core Technology Volume"

The books in the head first series are more interesting and easier to understand. "JAVA Core Technology Volume" is relatively moderate in difficulty and comprehensive in content, and some chapters (such as Swing) can be skipped.

basic knowledge of Java mainly includes:

class and object
Object-Oriented Features
abstract classes and interfaces
Data types, overriding overloading, encapsulation inheritance polymorphism
Container class Map/List/Set, etc.
IO operations: InputStream, OutputStream, Reader/Writer, file reading, various stream reading, etc.
exception handling
reflection mechanism
Generics
The role of the final keyword
throw and throws
custom exception
inner class
anonymous inner class

IO stream operations:

File class operations on files
byte stream write data
How to read data from byte stream
Byte stream completes the copying of video files
code table
character stream write data
String read data
Use of character buffer streams
standard input and output streams
object serialization stream
memory operation flow
RandomAccessFile
SequenceInputStream
compress stream/decompress stream

set basis :

Collection frame
Features of ArrayList Collection
Constructor of ArrayList
Common operations of ArrayList
HashMap、HashTable、Hashset
HashMap source code
Iterator Iterator
Map collection traversal
LinkedHashMap
ConcurrentHashMap

Java Web

Java Web is a synthesis of a series of technologies, and it is also the technical direction of most Java developers. It is necessary to learn. Check out the video tutorial for this part.

Video recommendation [Shang Silicon Valley]'s full set of JavaWeb tutorials, HTML/CSS/JavaScript and other related front-end can be viewed at double speed.

https://www.bilibili.com/video/BV1Y7411K7zz

The Java web tutorial of [Dark Horse Programmer] is generally good, IDEA version: https://www.bilibili.com/video/BV1qv4y1o79t

HTML&CSS (understand)

Basic use of HTML
HTML common tags
CSS selectors
What's New in HTML5
CSS3 new features

JavaScript (understand)

Embedding in JavaScript
Basic JavaScript syntax
ECMA6 new features
JavaScript flow control
array, function, object
JavaScript Object Oriented
Commonly used built-in objects
JavaScript event binding/triggering
JavaScript DOM manipulation and API
JavaScript BOM object and API

Servlet

Servlet overview
Servlet execution process analysis
Analysis of the Implementation of Servlet
The class of Servlet tries to explain in detail
Servlet life cycle
Analysis of Thread Safety of Servlet

Java EE

JavaEE Specification
Static and dynamic resources
C/S and B/S
Tomcat overview
Tomcat download and installation
Support for each version of Tomcat
Tomcat startup and startup problem analysis and solution
Tomcat directory structure
JavaEE Engineering Overview

tool

The first is Git, the version control tool, that must be mastered. Many students who have just started working may often encounter Git-related problems, such as code conflicts, branch merges, etc., so they still have to learn Git. Recommended Mad God video:

Git zero-based entry to actual combat detailed explanation:

https://www.bilibili.com/video/BV1FE411P7B3

Next up are Maven and Gradle, build tools used to build and manage various projects.

Getting started with maven zero basis:

https://www.bilibili.com/video/BV1TW411g7hP

Git basics

Git overview and features
Basic concepts of Git
Git History Version Control
Git branch version control
Git remote repository
Git remote hosting platform
Git conflict resolution

Maven Basics

Maven environment setup
Maven builds & automated builds
Local Warehouse & Central Warehouse
Maven creates Java and Web projects
pom.xml, dependency management
Coordinates, dependencies, lifecycle, etc.
Introduction to pom file dependency transitivity
Dependency conflict resolution
Maven project inheritance relationship
Maven project aggregation relationship
Building aggregated projects by sub-modules
Introduction and construction of private server warehouse
Upload local resources to private server
Download resources from private server to local
Install third-party resources to the local repository
Install third-party resources to private server repositories

Docker Basics

Docker image command
Docker container commands
Docker deploys MySQL, Redis, etc.
Container save to image
mirror backup
Image recovery and migration
Dockerfile
Docker Compose common commands
Docker private repository usage

database

The database is also a must-learn, mainly the Mysql database. Book Recommendations:

"mysql must know must know"
"High-performance mysql"

"mysql must know must know" is mainly the basic grammar of Mysql, which is easy to understand. After you have the foundation, look at "High Performance MySQL". This book mainly explains indexes, SQL optimization, advanced features, etc. Many MySQL related interview questions come from the book "High Performance MySQL", which is worth reading.

MySQL Basics:

CRUD
Transaction characteristics, isolation level
Indexing principle, optimization
b+ tree
Leftmost matching principle
storage engine
MVCC
Implementation plan
Sub-library and sub-table
log, bin log/undo log/redo log
complex query of data
use of constraints
Multi-table relationships (one-to-one, one-to-many, many-to-many)
Database restore and backup
Multi-table query operation
Business introduction
transaction isolation
Database user management and authority management
Use of views
Use of stored procedures
Use of triggers
Storage Engine Principle
Index efficient query
lock mechanism
database cluster

frame

Mainstream frameworks are:

spring: face-to-face, dependency injection, recommend the book "Spring in Action", and take you step by step to build Spring applications through demo
springboot: Habit is better than configuration, automatic configuration. At present, many companies use Spring Boot internally. Book recommendation "Spring Boot in action"
springmvc: a lightweight web framework based on the MVC architectural pattern
Mybatis: orm framework, recommended book "Mybatis in simple language"
springcloud: Now interviews are basically asked about microservices, and it is best to know about microservices. Service registration and discovery, load balancing, service degradation, API gateway, etc. Recommended book "spring cloud microservices in practice"

Spring

Spring overview
Coupling and Decoupling
Factory Design Pattern
IoC overview and role
The concept of dependency injection
Dependency Injection in Spring
Spring annotation-based IoC configuration
The use of common annotations
component scanner
BeanFactoryPostProcessor
BeanPostProcessor
InitializingBean

SpringMVC

Common Components
@RequestMapping annotation
Request parameter encapsulation
Notes on form validation
ServletAPI related annotation usage
Detailed explanation of the return value of the controller method
An introduction to asynchronous interactions and related annotations
Rest-style URLs
@PathVariable annotation
Detailed explanation of cross-domain access and use of @CrossOrigin annotation
Exception Handling in SpringMVC
Interceptors in SpringMVC

MyBatis

global configuration file
mapping configuration file
CRUD
Parameters in depth
result set encapsulation
Connection pooling and transactions in depth
dynamic sql statement
Multi-table query
lazy loading strategy
Add pagination plugin
log integration

Spring Boot

Core Features of SpringBoot
Advantages of SpringBoot
Analysis of the principle of starting dependence
Analysis of the principle of automatic configuration
Customize starter dependencies and implement automatic configuration
SpringBoot configuration file type
Attribute mapping method between configuration file and configuration class
SpringBoot integrates Mybatis
Custom Starter
event listener
initialization process

SpringCloud

Service registry Eureka introduction
Eureka server development
Microservice development and registration to the Eureka service registry
Eureka Protected Mode
Client load and server load
Ribbon implements client load balancing
Implementation of Feign
How Feign works
Avalanche effect and fuses
Fuses Hystrix use
Gateway introduction
Building Gateway Service Based on Gateway
Access microservices through Gateway
Spring Cloud Config
Configuration management using Git storage
Microservice transformation obtains configuration information from the configuration center
Introduction and application of service bus Spring Cloud Bus

Dubbo

Introduction to Dubbo
Dubbo Architecture
Dubbo service provider
Dubbo service consumer
Dubbo related configuration
monitoring Center
Architecture Principles
How It Works and Service Governance
Heartbeat and Communication

middleware

Redis

Advantages of Redis
Five data types of Redis
Basic Operation Commands
Redis persistence (RDB and AOF)
lua script
Distributed lock
pipeline
Redis Data Deletion Policy
Redis data elimination strategy
Cluster master-slave replication
Cluster Sentinel Mode

RocketMQ

Building RocketMQ
RocketMQ-Console
RocketMQ mode
message lost
message repeat
MQ-based distributed transaction solution description

JVM

JVM is also often asked in interviews. Java developers do not need to perform memory management and garbage collection by themselves. JVM does it for us, but it is still necessary to understand the working principle of JVM, so that when problems such as oom occur, they can have ideas to troubleshoot and solve problems. The book recommends Teacher Zhou's "In-depth Understanding of Java Virtual Machine".

Basic knowledge of jvm:

JVM memory structure (program counter, virtual machine stack, native method stack, heap, method area, runtime constant pool, direct memory)
class loading process
class file structure
object header
parental delegation
memory allocation and reclamation
Garbage Collection Algorithm
garbage collector
Tuning tools (jsp/jstack/jstat/jmap, just understand)

Concurrency

For the related content of concurrent programming, you can see the book "JAVA Concurrent Programming Practice". The main contents are:

Basic Definition of Thread
ways to implement threads
thread running status
Thread Pool Principle
Inter-thread communication
Locks (synchronized, ReentrantLock)
Concurrency tool class (CountDownLatch/CyclicBarrier/Semaphore)
Atomic class
AQS
Methods of communication between threads
thread synchronization
thread deadlock

computer basics

Usually take the time to learn basic computer knowledge, consolidate the foundation.

Data Structures and Algorithms

The recommended book "Data Structure and Algorithm Analysis Java Language Description", describes various data structures and algorithms in Java language, which is easier for Java developers to understand, mainly learn the following content:

Basic data structures (arrays, linked lists, stacks, queues, etc.)
Trees (binary trees, avl trees, b-trees, red-black trees, etc.)
heap structure
Sorting algorithms (bubble sort, selection sort, insertion sort, quick sort, merge sort, heap sort, etc. and time and space complexity)
dynamic programming
backtracking
how are you

computer network

The "Top-Down Approach to Computer Networks" is recommended:

network hierarchy
TCP/IP
Three handshakes four waves
Sliding window, congestion control
HTTP/HTTPS
the entire process of accessing a link
DNS
Network security issues (CSRF, XSS, SQL injection, etc.)

operating system

It's a big head to learn, you can go to station B to find the video, recommend Tsinghua University's open class . Book recommendation "In-depth understanding of computer systems", tome, classic books, it is worth reading several times.

Basics:

process thread
inter-process communication
thread synchronization
What is deadlock? producing conditions
Deadlock handling strategy
Pagination and segmentation difference
Process scheduling strategy
what is virtual memory
page replacement algorithm
signal
...

linux

Recommended book "Brother Bird's Linux Private Kitchen".

The above is the Java learning route. It takes at least half a year to learn the entire route. Persistence is victory!

Finally, I will share with you a github repository, which more than 200 classic computer books , including C language, C++, Java, Python, front-end, database, operating system, computer network, data structure and algorithm, machine learning, programming Life, etc., you can star, and the next time you find a book, you can directly search on it, the warehouse is continuously updated~

github repository: https://github.com/Tyson0314/java-books

If github cannot be accessed, you can access the gitee repository.

gitee repository: https://gitee.com/tysondai/java-books

It is not easy to code words. If you find it helpful, you can !

I'm @Programmer Dabin, I regularly share the core knowledge of Java background, welcome everyone to pay attention~