preface

Because work needs, try to learn and use Java, this article mainly records the Java development environment related configuration

Java

Java Runtime Environment

introduce

The Java Runtime Environment (JRE) is a collection of environments necessary to run Java programs, including the JVM standard implementation and Java core class libraries. JRE is a Java runtime environment and is not a development environment, so it does not include any development tools (such as compilers and debuggers)

JRE is designed for the Java program running environment. In the development environment, you only need to install JDK, which contains JRE

Download, install, use

Visit the Official Java website to download, install, and use the Java software.

Official website: www.java.com

Java Development Kit

introduce

Java Development Kit (JDK) is a Java software Development Kit for Java developers, including the JRE, a bunch of Java tools (Javac/Java/JDB…). And java-based class libraries (that is, Java apis including Rt.jar). For a Java programmer, the use of the JDK is a basic skill.

download

Go to the JDK product download page on the Oracle website and find the specific JDK version to download.

Because Java is cross-platform, you need to pay attention to the CPU platform as well as the operating system platform. In addition, to download JDK8 from Oracle, you also need to log in to Oracle account, and the registration process is very tedious, so I accidentally found a magical website bugmenot.com

Download page: www.oracle.com/java/techno…

The installation

JDK 8U251-macosx-x64. DMG file is downloaded from Oracle’s official website. If you mount JDK 8U251-Macosx-x64. DMG file, you will get JDK8 Update 251. PKG file.

You can then check the currently installed Java version by using Java –version

configuration

TODO

check

TODO

uninstall

Uninstall Java completely on MacOS and run the following commands one at a time

Delete related system components
sudo rm -fr /Library/Internet\ Plug-Ins/JavaAppletPlugin.plugin 
sudo rm -fr /Library/PreferencesPanes/JavaControlPanel.prefpane

# find the current version
ls /Library/Java/JavaVirtualMachines/

# Delete related versionsSudo rm - rf/Library/Java/JavaVirtualMachines/JDK - 9.0.1. JDKCopy the code

Maven

introduce

Maven is a dedicated tool for building and managing Java-related projects

download

Download the Archive from the Download page of the Maven project official website

Download address: maven.apache.org/download.cg…

The installation

For example, to install Maven 3.6.3 on MacOS, download the apache-Maven-3.6.3-bin. zip file, decompress it and move the binary file to a specific directory

/apache-maven-3.6.3-bin.zip mv./apache-maven-3.6.3 ~/JavaLibrary/Copy the code

Then add the following configuration to ~/.bash_profile to add Maven’s executables to the PATH environment variable

The export PATH = $PATH: ~ / JavaLibrary/apache maven - 3.6.3 / binCopy the code

Then run source ~/.bash_profile for this to take effect

Then you can run mvN-v to check whether the configuration takes effect

Optional configuration

Add a domestic mirror mirror warehouse

Setting up a Maven project requires going to the repository to download some dependencies. The default central repository of Maven is the UK, so the download may fail or be very slow due to inconvenient access to the external network in China, so we changed the central repository to the domestic one.

Open ~/JavaLibrary/apache-maven-3.6.3/conf/settings. XML, find the mirrors node, and add the following content to it

<mirror>
    <id>maven.net.cn</id>
    <mirrorOf>central</mirrorOf>
    <name>mirror in china</name>
    <url>http://maven.net.cn/content/groups/public/</url>
</mirror>
Copy the code

use

TODO

Spring

download

TODO