Figure and text explain the steps of creating a new Maven webapp project in MyEclipse (very detailed)

The process of creating a new Maven project (webapp directory structure) in MyEclipse is as follows:

 

1. New -> Project... -> Maven Project

 

2. Next, 

 

3. Next, select "maven-archetype-webapp" to create a project with a webapp directory structure

4. Fill in Group Id, Artifact Id, and Package (please refer to "Keywords" below), and click "Finish"

5. Take a break and wait for MyEclipse to create the project

After the creation is complete, the file directory structure is as follows:

 

6. (If you don't like the current file name) Modify the project name and storage path : right-click on the project -> refactor -> rename

7. Add the code directory:

Note: If it is MyEclipse2015, you only need to change the JRE System Library to "Workspace default JRE" in Java Build Path -> Libraries to automatically have those directories without the following operations.

Right-click on the project -> Build Path -> New Source Folder..., fill in "src/main/java"

(Note: MyEclipse2015 does not have this menu, just do this: right-click the project -> New -> Folder -> Folder Name, enter "src/main/java", and then repeat the steps to enter "src/test/java")

 

 

After adding, the test directory also automatically has:

 

8. (If necessary) modify the jdk used by the project: right-click the project -> Build Path -> Configure Build Path...

 

 

The final project directory structure is as follows:

9. Add the corresponding plugin , such as maven-compiler-plugin

[html] view plain copy

 

print ?

1. <plugin>  
2.  <groupId>org.apache.maven.plugins</groupId>  
3.  <artifactId>maven-compiler-plugin</artifactId>  
4.  <version>2.3.2</version>  
5.  <configuration>  
6.   <source>1.7</source>  
7.   <target>1.7</target>  
8.  </configuration>  
9. </plugin>  

   <plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-compiler-plugin</artifactId>
    <version>2.3.2</version>
    <configuration>
     <source>1.7</source>
     <target>1.7</target>
    </configuration>
   </plugin>

Key words:

GroupId: usually company name or organization name

ArtifactId: usually the project name

Packaging：打包类型，jar/war/rar/ear/pom等，默认是jar

Version：版本号，GroupId+ArtifactId+Packaging+Version构成项目的唯一标识

Snapshot：标识一个正在开发阶段、会经常更新、但尚未发布的版本

 

<dependency management>和<dependencies>的区别：

在父POM中用<dependency management>定义好version, scope, 和exclusions后，可以被子POM中用<dependencies>定义的依赖所继承使用。这样，如果有多个子POM的话，可以确保用同一套version, scope, 和exclusions。

 

Dependency Scope:

• compile: 默认的scope。编译、测试、打包全都需要。compile参与依赖传递，就是说，项目A依赖于B(依赖scope是compile)，项目C依赖于你的项目A，那么C也就依赖于B。
• provided: 表示JDK或者容器会在Runtime时提供这些(jar)，如servlet api，部署时是不需要它的，因为应用服务器肯定有这些东西。provided的东西在编译和测试时会用到，不参与传递依赖。
• runtime: 表示编译时不需要，但测试和运行时需要，最终打包时会包含进去。
• test: 只用于测试阶段（测试的编译和测试的运行），典型的就是junit的jar。
• system: 和provided类似，但要求jar是系统里已有的，不会在repository里找，如rt.jar,tools.jar这些。
• import: 简单的说，项目的pom可以继承另一个项目的pom，从而继承了父项目的依赖关系，但是因为之后single inheritance的限制，所以创造了import，使得你可以“导入”或者说“继承”任何一到多个项目的依赖关系。

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找包的方法：

1. 在GOOGLE里输入: maven spring repository 
2. 得到：

[html] view plain copy

 

print ?

1. <dependency>    
2.     <groupId>org.springframework</groupId>  
3.     <artifactId>spring</artifactId>  
4.     <version>2.5.5</version>  
5. </dependency>   

<dependency>  
    <groupId>org.springframework</groupId>
    <artifactId>spring</artifactId>
    <version>2.5.5</version>
</dependency> 

等Maven下载完jar包后，

1. Stop server
2. Redeploy/Reload application
3. Start serve