preface

• Maven is a project construction and management tool, which can be used to build and manage JAVA projects.
• Maven uses the Project Object Model (POM) to manage the project.
• Maven's main work is to parse some XML documents and manage the life cycle and plug-ins.
• Maven is designed to delegate the main responsibilities to a group of Maven plug-ins, which can affect the Maven life cycle and provide access to the target.

0x01 Maven environment configuration

1. JDK installation and system requirements

Maven is a Java based tool, so the first thing to do is to install JDK (Baidu). System requirements

2. Maven installation and environment variable configuration

Mevan Download: http://maven.apache.org/download.cgi

Download Maven package and decompression path on the corresponding platform

Set Maven environment variable

Windows

New system variable: MAVEN_HOME, variable value: e: maven apache-maven-3.3 nine

Edit system variable Path and add variable value:;% MAVEN_HOME%bin

Linux

Download and extract:

# wget http://mirrors.hust.edu.cn/apache/maven/maven-3/3.3.9/binaries/apache-maven-3.3.9-bin.tar.gz
# tar -xvf  apache-maven-3.3.9-bin.tar.gz
# sudo mv -f apache-maven-3.3.9 /usr/local/

Edit the / etc/profile} sudo vim /etc/profile and add the following code at the end of the file:

export MAVEN_HOME=/usr/local/apache-maven-3.3.9
export PATH=${PATH}:${MAVEN_HOME}/bin

Save the file and run the following command to make the environment variable effective:

Enter the following command on the console. If you can see the relevant version information of maven, it indicates that Maven has been successfully installed:

# source /etc/profile
# mvn -v

Mac

Download and extract:

$ curl -O http://mirrors.hust.edu.cn/apache/maven/maven-3/3.3.9/binaries/apache-maven-3.3.9-bin.tar.gz
$ tar -xvf  apache-maven-3.3.9-bin.tar.gz
$ sudo mv -f apache-maven-3.3.9 /usr/local/

Edit the / etc/profile} sudo vim /etc/profile and add the following code at the end of the file:

export MAVEN_HOME=/usr/local/apache-maven-3.3.9
export PATH=${PATH}:${MAVEN_HOME}/bin

Save the file and run the following command to make the environment variable effective:

$ source /etc/profile

Enter the following command on the console. If you can see the relevant version information of maven, it indicates that Maven has been successfully installed:

$ mvn -v
Apache Maven 3.3.9 (bb52d8502b132ec0a5a3f4c09453c07478323dc5; 2015-11-11T00:41:47+08:00)
Maven home: /usr/local/apache-maven-3.3.9
Java version: 1.8.0_31, vendor: Oracle Corporation
Java home: /Library/Java/JavaVirtualMachines/jdk1.8.0_31.jdk/Contents/Home/jre
Default locale: zh_CN, platform encoding: ISO8859-1
OS name: "mac os x", version: "10.13.4", arch: "x86_64", family: "mac"

0x02 Maven introduces external dependencies

Project structure

If our project needs to introduce external dependencies, you can use POM Add dependency to XML file

eg:sevlet Dependence of

        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>

Complete POM XML file

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>javaweb-03-jsp</artifactId>
    <packaging>pom</packaging>
    <version>1.0-SNAPSHOT</version>
    <modules>
        <module>servlet-01</module>
    </modules>
    <dependencies>
        <!-- https://mvnrepository.com/artifact/taglibs/standard -->
        <dependency>
            <groupId>taglibs</groupId>
            <artifactId>standard</artifactId>
            <version>1.1.2</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>4.0.1</version>
            <scope>provided</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/javax.servlet.jsp/javax.servlet.jsp-api -->
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>javax.servlet.jsp-api</artifactId>
            <version>2.3.3</version>
            <scope>provided</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/javax.servlet.jsp.jstl/jstl -->
        <dependency>
            <groupId>javax.servlet.jsp.jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

    </dependencies>

</project>

The dependent packages used in the project will be imported and used in the lib file under the WEB-INF folder when generating war

Dependent libraries: https://mvnrepository.com/