Maven_2_核心知識

時間  2019-11-19
標籤 maven 核心 知識 欄目 Maven 简体版
原文   原文鏈接

Documentation http://maven.apache.org/guides/index.htmlhtml

-----3-1 經常使用構建命令------------------------------------------------------------------------------------------------------java

mvnreact

　　-vspring

　　compileapache

　　test 測試windows

　　package 打包服務器

　　

　　clean 刪除targetapp

　　　　

D:\java\code\maven01>mvn clean
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building maven01-model 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ maven01-model ---
[INFO] Deleting D:\java\code\maven01\target
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 4.228 s
[INFO] Finished at: 2017-06-27T17:22:55+08:00
[INFO] Final Memory: 9M/104M
[INFO] ------------------------------------------------------------------------

 

　　install 安裝jar包到本地倉庫框架

　　example：maven02 中使用maven01的類eclipse

     1) cd 到maven01 目錄　，mvn install 把jar包安裝到本地倉庫

　　　　

[INFO] Installing D:\java\code\maven01\target\maven01-model-0.0.1-SNAPSHOT.jar to C:\Users\30478\.m2\repository\com\iooc\maven01-model\0.0.1-SNAPSHOT\maven01-model-0.0.1-SNAPSHOT.jar
[INFO] Installing D:\java\code\maven01\pom.xml to C:\Users\30478\.m2\repository\com\iooc\maven01-model\0.0.1-SNAPSHOT\maven01-model-0.0.1-SNAPSHOT.pom
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 10.419 s
[INFO] Finished at: 2017-06-27T17:40:35+08:00
[INFO] Final Memory: 18M/168M
[INFO] ------------------------------------------------------------------------

 

　 2） 在maven02的pom.xml中添加依賴，

<?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><!--固定-->
    <groupId>com.imooc.maven02</groupId><!--groupId項目包名-->
    <artifactId>maven02-model02</artifactId><!--artifactId模塊名；建議使用項目名-->
    <version>0.0.1SNAPSHOT</version><!--快照版本-->
    <dependencies>
        <dependency>
            <!--junit依賴-->
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.10</version>
        </dependency>
        <dependency>
                <groupId>com.iooc</groupId>
                <artifactId>maven01-model</artifactId>
                <version>0.0.1-SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

 

　　

 

再cd 到maven02 ,執行mvn compile

D:\java\code\maven02>mvn compile
[INFO] Scanning for projects...
[WARNING]
[WARNING] Some problems were encountered while building the effective model for com.imooc.maven02:maven02-model02:jar:0.0.1SNAPSHOT
[WARNING] 'version' uses an unsupported snapshot version format, should be '*-SNAPSHOT' instead. @ line 9, column 11
[WARNING]
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING]
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building maven02-model02 0.0.1SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ maven02-model02 ---
[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory D:\java\code\maven02\src\main\resources
[INFO]
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ maven02-model02 ---
[INFO] Changes detected - recompiling the module!
[WARNING] File encoding has not been set, using platform encoding GBK, i.e. build is platform dependent!
[INFO] Compiling 1 source file to D:\java\code\maven02\target\classes
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.909 s
[INFO] Finished at: 2017-06-27T17:43:33+08:00
[INFO] Final Memory: 13M/162M
[INFO] ------------------------------------------------------------------------

 經過mvn compile編譯源代碼，若是在編譯的過程當中程序用到了其餘的依賴包，它會去pom.xml中查找是否引入了該依賴包的座標（groupId,artifactId,version），
若是找到了該座標，會去本地倉庫中查找是否有相應的jar,若是沒有的話，會去maven的中央倉庫中去找並下載到本地倉庫中，供項目引用。

----maven 自動創建目錄骨架-------------------------------------------------------------------------------------------------------

創建maven03 目錄

cd 到maven03根目錄,

方式1 archetype:generate 按照提示：

mvn archetype:generate 會先下載依賴的jar

1878: remote -> us.fatehi:schemacrawler-archetype-plugin-lint (-)
Choose a number or apply filter (format: [groupId:]artifactId, case sensitive contains): 991: 回車
Choose org.apache.maven.archetypes:maven-archetype-quickstart version:
1: 1.0-alpha-1
2: 1.0-alpha-2
3: 1.0-alpha-3
4: 1.0-alpha-4
5: 1.0
6: 1.1
Choose a number: 6: 6 選擇版本，此處選6

groupId: com.imooc.mavne03
artifactId: maven03-service
version: 1.0.0SNAPSHOT
package: com.imooc.maven03.server
 Y: : y
-archetype-1.0.0.jar (3.7 kB at 8.3 kB/s)
Define value for property 'groupId': com.imooc.mavne03
Define value for property 'artifactId': maven03-service
Define value for property 'version' 1.0-SNAPSHOT: : 1.0.0SNAPSHOT
Define value for property 'package' com.imooc.mavne03: : com.imooc.maven03.server
Confirm properties configuration:
groupId: com.imooc.mavne03
artifactId: maven03-service
version: 1.0.0SNAPSHOT
package: com.imooc.maven03.server
 Y: : y
 Y: : y
[INFO] ----------------------------------------------------------------------------
[INFO] Using following parameters for creating project from Archetype: maven-reactjs-blank-archetype:1.0.0
[INFO] ----------------------------------------------------------------------------
[INFO] Parameter: groupId, Value: com.imooc.mavne03
[INFO] Parameter: artifactId, Value: maven03-service
[INFO] Parameter: version, Value: 1.0.0SNAPSHOT
[INFO] Parameter: package, Value: com.imooc.maven03.server
[INFO] Parameter: packageInPathFormat, Value: com/imooc/maven03/server
[INFO] Parameter: package, Value: com.imooc.maven03.server
[INFO] Parameter: version, Value: 1.0.0SNAPSHOT
[INFO] Parameter: groupId, Value: com.imooc.mavne03
[INFO] Parameter: artifactId, Value: maven03-service
[WARNING] CP Don't override file D:\java\code\maven03-service\app\components\Greet.jsx
[WARNING] CP Don't override file D:\java\code\maven03-service\app\components\App.jsx
[INFO] Project created from Archetype in dir: D:\java\code\maven03-service
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 05:53 min
[INFO] Finished at: 2017-06-28T16:28:55+08:00
[INFO] Final Memory: 15M/135M
[INFO] ------------------------------------------------------------------------

 

方式2 一次性輸入全部參數(注意 參數名與參數值之間不能有空格 錯： -DartifactId= maven04-model ）

使用mvn archetype:generate -DgroupId=組織名 -DarticfactId=項目名-模塊名 -Dversion=... -Dpackage=包 等待加載相應的依賴

mvn archetype:generate -DgroupId=com.imooc.maven04 -DartifactId=maven04-demo -Dversion=1.0.0SNAPSHO
T -Dpackage=com.imooc.maven04.demo

Choose a number or apply filter (format: [groupId:]artifactId, case sensitive contains): 991: 回車
Choose org.apache.maven.archetypes:maven-archetype-quickstart version:
1: 1.0-alpha-1
2: 1.0-alpha-2
3: 1.0-alpha-3
4: 1.0-alpha-4
5: 1.0
6: 1.1
Choose a number: 6: 6
[INFO] Using property: groupId = com.imooc.maven04
[INFO] Using property: artifactId = maven04-demo
[INFO] Using property: version = 1.0.0SNAPSHOT
[INFO] Using property: package = com.imooc.maven04.demo
Confirm properties configuration:
groupId: com.imooc.maven04
artifactId: maven04-demo
version: 1.0.0SNAPSHOT
package: com.imooc.maven04.demo
 Y: : y

 

Choose a number or apply filter (format: [groupId:]artifactId, case sensitive contains): 991:
Choose org.apache.maven.archetypes:maven-archetype-quickstart version:
1: 1.0-alpha-1
2: 1.0-alpha-2
3: 1.0-alpha-3
4: 1.0-alpha-4
5: 1.0
6: 1.1
Choose a number: 6: 6
[INFO] Using property: groupId = com.imooc.maven04
[INFO] Using property: artifactId = maven04-demo
[INFO] Using property: version = 1.0.0SNAPSHOT
[INFO] Using property: package = com.imooc.maven04.demo
Confirm properties configuration:
groupId: com.imooc.maven04
artifactId: maven04-demo
version: 1.0.0SNAPSHOT
package: com.imooc.maven04.demo
 Y: : y
[INFO] ----------------------------------------------------------------------------
[INFO] Using following parameters for creating project from Old (1.x) Archetype: maven-archetype-quickstart:1.1
[INFO] ----------------------------------------------------------------------------
[INFO] Parameter: basedir, Value: D:\java\code\maven03
[INFO] Parameter: package, Value: com.imooc.maven04.demo
[INFO] Parameter: groupId, Value: com.imooc.maven04
[INFO] Parameter: artifactId, Value: maven04-demo
[INFO] Parameter: packageName, Value: com.imooc.maven04.demo
[INFO] Parameter: version, Value: 1.0.0SNAPSHOT
[INFO] project created from Old (1.x) Archetype in dir: D:\java\code\maven03\maven04-demo
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 01:59 min
[INFO] Finished at: 2017-06-28T16:57:41+08:00
[INFO] Final Memory: 19M/207M
[INFO] ------------------------------------------------------------------------

 

 

----3-3 maven 中的座標和倉庫-------------------------------------------------------------------------------------------------------

座標  groupId,artifactId,version構成一個座標，在maven項目中，全部的依賴，插件，項目構建的輸出均可以稱之爲‘構件’，構件經過座標做爲其惟一標識。

　　構件 (groupId,artifactId,version等)

    <groupId>com.imooc.mavne03</groupId>
    <artifactId>maven03-service</artifactId>
    <version>1.0.0SNAPSHOT</version>  組成基本座標

(package 名應與groupId 和 artifactId 相吻合，看起來更加清晰)

 

倉庫(依賴)

　　本地倉庫和遠程倉庫 

 

maven提供的超級pom:下載的maven/lib/maven-model-builder-3.3.3.jar/org/apache/maven/model/pom-4.0.0.xml
 

 
 
　　url爲全球的中央倉庫的地址，http://repo.maven.apache.org/maven2
 
 
　　id表示惟一標識，name爲名稱，url爲地址，layout爲佈局，snapshot爲快照版本，<enabled>false</enabled>表示禁止下載快照的版本。
 
 
鏡像倉庫的概念：A提供和B同樣的功能。
　　maven中修改鏡像倉庫位置的文件：maven/conf/settings.xml  裏mirrors
 
 
　　id爲倉庫標識，mirrorOf表示爲誰建立鏡像倉庫，name爲鏡像倉庫的命名，url爲鏡像倉庫地址
 
 
倉庫默認放在當前用戶的目錄中，.m2目錄
 
 
　　更改倉庫位置:找到maven的conf/settings.xml中的<localRepository></localRepository>爲設置的路徑，並把settings.xml拷貝到新建立的路徑中，這樣每次更新maven,就不用從新設置倉庫路徑了
 

 

---3-4 eclipse中安裝maven插件以及建立maven項目------------------------------------------------------------------------------------
 

eclipse4.0以上版本，myEclipse不須要安裝
 

　　查看方式 Eclipse-Windows-preferences中是否有maven選項
 

說明以3.6版本爲例子：
 

　1.安裝maven插件
 

　　　下載好的maven插件 放入eclipse/dropins目錄，就完成安裝，而後重啓eclipse
 

 
 
　　放入到插件目錄後，windows-preference中點擊maven若是有如圖所示的彈出框，表示eclipse須要jdk支持，能夠 點擊其中的eclipse.ini在其中配置jvm
 
 
 
  　　  在eclipse.ini中配置JVM -vm 加jdk路徑\javaw.exe 
 
 
 
 
  
　　配置與jdk相匹配的jre(preferences -java-Installed JREs)
 
 
 

 

 
 　　   更改maven的默認配置爲本地maven (preferences -Maven-Instllations) 

 

 
 
　　修改settings.xml的路徑（preferences -Maven-User Settings本身配置的本地倉庫的路徑）。
 2 新建maven項目
　　新建maven項目- new -other-maven- maven project
　　　　目錄模板選擇quickstart
　　　　配置groupId,artifactId,version,點擊finish
　　　　運行新建的maven項目，pom.xml點擊右鍵-->run as-->maven build
　　　　在Main的goals中輸入compile命令
　　　　console中報紅字，此時項目並無編譯，此時在JRE的Default VM Arguments中配置'相應的報紅字'=$M2_HOME
　　　　　　（右擊項目-run as-maven build-輸入compile報錯： -Dmaven.multiModuleProjectDirectory system property is not set. Check $M2_HOME environment variable and mvn script match. 解決辦法： Windows-preferences-Java-InstalledJRE-edit, -Dmaven.multiModuleProjectDirectory=$M2_HOME）
　　　　控制檯無報錯，一樣步驟在goals中輸入 package命令。
　　　　進入項目根目錄進行查看，生成target文件，裏面有classes,reports及相應的項目jar包
 

 

-----3-5 maven的生命週期和插件-----------------------------------------------------------------------------------
 

一個項目的完整的構建過程：清理·編譯·測試·打包·集成測試·驗證·部署
 

maven抽象出一套項目構建的生命週期，插件是對maven抽象的具體實現。

 

maven構建了三套項目生命週期，clean 清理項目，default 構建項目，site 生成項目站點
 

三個生命週期是相互獨立的，每一個生命週期之間又包含相應的階段，每一個階段之間又是有順序的。
 

且後一個階段依賴前一個階段，階段之間是有順序的，此階段的執行不會觸發其餘的生命週期。
 

運行package時，雖然沒有執行compile和test,可是這兩個命令是依次執行的。（執行maven生命週期中的某個階段時，其前面的每一個階段會依次執行。）
 

clean 清理項目
　　pre-clean 執行清理前的工做
　　clean 清理上一次構建生成的全部文件
　　post-clean 執行清理後的文件
 

default包含構建項目時所要執行的步驟。
 

　　compile test package install屬於default默認的生命週期中。
 

site會根據pom.xml中的相關信息生成站點。
　　pre-site 在生成項目站點前要完成的工做
　　site 生成項目的站點文檔
　　post-site 在生成項目站點後要完成的工做
　　site-deploy 發佈生成的站點到服務器上
 

eclipse默承認操做的語言爲java,但能夠經過第三方插件來運行PHP,c等語言，這些語言運行時所須要執行的相似javac.exe則來自於插件中。maven也是經過插件的方式調用compile,test等。若是要在maven項目中添加一個插件，須要在pom.xml中添加
 

******
 

　　plugins參照                                                                                   
 

　　http://maven.apache.org/plugins/index.html                                
 

　　本例子：http://maven.apache.org/plugins/maven-source-plugin/
 

******

<build>
      <plugins>
          <plugin>
              <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-source-plugin</artifactId>
            <version>2.4</version>
            <executions>
                <execution>
                    <phase>package</phase>  <!-表示在package命令中執行此source插件- -->
                    <goals>
                           <goal>jar-no-fork</goal>
                    </goals>
                </execution>
            </executions>
          </plugin>
      </plugins>
  </build>
 

 
 
<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>com.imooc.hellow</groupId>
  <artifactId>mode</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>mode</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
  <build>
      <plugins>
          <plugin>
              <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-source-plugin</artifactId>
            <version>2.4</version>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                           <goal>jar-no-fork</goal>
                    </goals>
                </execution>
            </executions>
          </plugin>
      </plugins>
  </build>
</project>
 

 

goals中輸入package ，執行 結果：
 

[INFO] Scanning for projects...
[INFO] 
[INFO] ------------------------------------------------------------------------
[INFO] Building mode 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ mode ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory D:\java\workspace\mode\src\main\resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ mode ---
[INFO] Nothing to compile - all classes are up to date
[INFO] 
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ mode ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory D:\java\workspace\mode\src\test\resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ mode ---
[INFO] Nothing to compile - all classes are up to date
[INFO] 
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ mode ---
[INFO] Surefire report directory: D:\java\workspace\mode\target\surefire-reports

-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running com.imooc.hellow.mode.AppTest
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.013 sec

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

[INFO] 
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ mode ---
[INFO] Building jar: D:\java\workspace\mode\target\mode-0.0.1-SNAPSHOT.jar
[INFO] 
[INFO] --- maven-source-plugin:2.4:jar-no-fork (default) @ mode ---
[INFO] Building jar: D:\java\workspace\mode\target\mode-0.0.1-SNAPSHOT-sources.jar
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 19.411 s
[INFO] Finished at: 2017-06-29T10:29:43+08:00
[INFO] Final Memory: 17M/168M
[INFO] ------------------------------------------------------------------------
package 執行時自動執行了compile,test  ,並且打包了source
 


執行maven生命週期中的某個階段時，其前面的每一個階段會依次執行。
 

 
 

 
 

 
 

 
 

 
 

-----3-6 maven中Pom.xml解析-----------------------------------------------------------------------------------------------
 

pom.xml是maven項目的核心管理文件，用於項目描述，組織管理，依賴管理，構件信息的管理。
 

 project是pom.xml的根元素，設定一些約束。
 

modelVersion指定了當前pom的版本，其次是座標的信息，groupId爲主項目標識，表示maven屬於哪一個主項目，由反寫的公司網址+項目名組成。
 

實際的項目和maven項目會有些不一樣，maven項目體現的是一個模塊化的概念，一個項目可能有幾個模塊構成。
 

artifactId就是項目實際的模塊，項目名+模塊名構成。
 

version表示版本號，通常有三個0構成，第一個0表示大版本好，第二個0表示分支版本號，第三個0表示小版本號。snapshot快照版本。版本有快照版本，α版本（內測版本）以及beta版本（公測版本），還有release版本，ga版本，release版本爲一個穩定的版本，ga版本爲一個正式的發佈版本。
 

packaging標籤表示maven項目默認的打包方式，默認爲jar,也有war,zip，pom包。
 

 
 

name爲項目描述名，url爲項目地址，description爲項目描述，developers爲開發人員信息，licenses爲許可證信息。
 

organization爲組織信息。
 

dependencies表示依賴列表，dependency表示依賴項，scope表示依賴範圍，optional表示設置依賴是否可選，默認爲false,默認繼承，爲true則項目必須加載依賴項。exclusions表示排除依賴傳遞列表，好比若是項目引用spring，spring中被引用其餘jar也會被引用，此爲依賴傳遞。
 

dependencyManagement爲依賴的管理，通常用於父模塊中，運行時不會被編譯加載依賴。用於子模塊繼承父模塊中依賴，好比junit測試依賴。
 

build中爲插件列表，會放相應的插件，parent用於對父模塊中pom的繼承，modules用於當項目啓動時，須要多個模塊是，對其餘項目進行編譯，不須要一個個進行編譯。

 

 
 
pom.xml經常使用元素介紹：
<project>根
<modelVersion>指定了當前pom的版本
<groupId>反寫的公司網址+項目名
<artifactId>項目名+模塊名
<version>第一個0表示大版本號、第二個0表示分支版本號、第三個0表示小版本號
0.0.1SNAPSHOT
<packaging>打包方式，默認是jar
<name>項目描述名
<url>項目地址
<description>項目描述
<developers>開發人員列表
<licenses>許可證信息
<organization>組織信息

<dependencies>
 <dependence>座標groupId,artifactId,version
   <groupId></groupId>
   <artifactId></artifactId>
   <version></version>
   <type></type>
   <scope></scope>依賴範圍
   <optional></optional>設置依賴是否可選，true必須顯示的引入該依賴/false繼承
    <exclusions>排除依賴傳遞列表(a依賴b，b依賴c,c對a 就是傳遞依賴)
　　　　<exclusion>
　　　　</exclusion>
　　</exclusions></dependence>
</dependencies>
依賴管理
<dependencyManagement>
　　<dependence>
　　</dependence>
</dependencyManagement>
<build>
 <plugins>
  <plugin> </plugin>  
 </plugins>
</build>
 

 

---3-7 maven 依賴範圍dependency scope ----------------------------------------------------------------------
 

Documentation script：http://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html
 

當咱們要引用某個框架的話，須要把項目的jar放入到項目的classpath中，這樣項目就能夠引用框架的jar了。
maven提供了三種calsspath，1編譯，2測試，3運行
dependency中的scope就是控制依賴的範圍，test表示僅在測試的classpath中。
scope有六種，compile,provided,runtime,test,system,import
provided在編譯和測試時有效。
runtime在測試和運行時有效。
system與本機系統相關聯，可移植性差，好比利用到本機的jdk配置。
import僅使用在dependencyManagement中，表示從其它的pom中導入dependency的配置。
如圖表示將a中的依賴導入到B中。
<name>B</name>
 

<dependencyManagement>
　　<dependences>
 

　　  <dependencey>
 

　　　　<groupId>maven</groupId> 
 

　　　　<artifactId>A</artifactId> 
 

　　　　<version>1.8</version> 
 

　　　　<type>pom</type>
 

　　　　<scope>import</scope>
 

　　   </dependencey>
　　</dependences>
</dependencyManagement>
 

----3-8 maven依賴傳遞-------------------------------------------------------------------------------------------------------
 

 建立三個maven項目bge,nange,shanji。nange依賴bge項目啓動，shanji依賴nange啓動，啓動下層項目時，上層須要打成jar。如圖若是不寫其中的exclusion中的內容時，shanji也會依賴bge的jar。此爲傳遞依賴。
 

下層項目啓動，上層沒有打包，安裝時的error msg。goals中直接輸入clean 
 

 
 
[INFO] Scanning for projects...
[INFO] 
[INFO] ------------------------------------------------------------------------
[INFO] Building shanji 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[WARNING] The POM for com.hongxing:nange:jar:0.0.1-SNAPSHOT is missing, no dependency information available
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.306 s
[INFO] Finished at: 2017-06-29T13:59:32+08:00
[INFO] Final Memory: 6M/123M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project shanji: Could not resolve dependencies for project com.hongxing:shanji:jar:0.0.1-SNAPSHOT: Could not find artifact com.hongxing:nange:jar:0.0.1-SNAPSHOT -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyResolutionException
 

 

 
 

 bge b哥 (mvn package,mvn install 以後 nange才能找到(打包安裝在本地倉庫中))
 

　　安裝成功log
 

 
 
[INFO] 
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ nange ---
[INFO] 
[INFO] --- maven-install-plugin:2.4:install (default-install) @ nange ---
[INFO] Installing D:\java\workspace\nange\target\nange-0.0.1-SNAPSHOT.jar to D:\java\localRepository\com\hongxing\nange\0.0.1-SNAPSHOT\nange-0.0.1-SNAPSHOT.jar
[INFO] Installing D:\java\workspace\nange\pom.xml to D:\java\localRepository\com\hongxing\nange\0.0.1-SNAPSHOT\nange-0.0.1-SNAPSHOT.pom
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.904 s
[INFO] Finished at: 2017-06-29T14:01:29+08:00
[INFO] Final Memory: 12M/155M
[INFO] ------------------------------------------------------------------------
 

 

 
 

nange 南哥 (mvn package,mvn install 以後 shanji才能找到(打包安裝在本地倉庫中))
 

shanji 山雞
 

 bge pom.xml
 

 
 
<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>com.hongxing</groupId>
  <artifactId>bge</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>bge</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>
 

 

nange pom.xml
 

 
 
<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>com.hongxing</groupId>
  <artifactId>nange</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>nange</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>com.hongxing</groupId>
          <artifactId>bge</artifactId>
          <version>0.0.1-SNAPSHOT</version>
    </dependency>
  </dependencies>
</project>
 

 

shanji
 

 
 
<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>com.hongxing</groupId>
  <artifactId>shanji</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>shanji</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>com.hongxing</groupId>
          <artifactId>nange</artifactId>
          <version>0.0.1-SNAPSHOT</version>
    </dependency>
  </dependencies>
</project>
 

 

 
 

 
 

 排除bge的依賴
 

 
 
<dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>com.hongxing</groupId>
          <artifactId>nange</artifactId>
          <version>0.0.1-SNAPSHOT</version>
          <exclusions>
              <exclusion>
                  <groupId>com.hongxing</groupId>
                  <artifactId>bge</artifactId>
              </exclusion>
          </exclusions>
    </dependency>
  </dependencies>
 

 

 

bge已經被排除
 

 注意 ：JRE System Library 的版本maven 默認爲1.5,此處已經手工修改成1.8
 

　　      能夠經過修改settings.xml來改變。
 

　　可參照：如何修改maven的默認jdk版本
 

　　　　182行左右 找到 <profiles>添加以下代碼
 

　　　　　　
 

 
 
  <profiles>
      <profile>    
    <id>jdk-1.8</id>    
     <activation>    
          <activeByDefault>true</activeByDefault>    
          <jdk>1.8</jdk>    
      </activation>    
    <properties>    
        <maven.compiler.source>1.8</maven.compiler.source>    
        <maven.compiler.target>1.8</maven.compiler.target>    
        <maven.compiler.compilerVersion>1.8</maven.compiler.compilerVersion>    
    </properties> 
 

 

 
 

 
 

要點1：install指令能把項目打包到本地倉庫，運行install指令，同時還運行了package打包。 編譯一個項目，若是存在依賴，首先會在本地倉庫查找，若是沒找到，直接到中央倉庫查找，若是仍是沒找到，則報錯。因此編譯一個存在本地依賴的項目，本地依賴必定要運行install指令，把依賴的項目打包到本地倉庫。 要點2： 若是想排除某個依賴的項目，則須要在pom.xml添加exclusions標籤，添加到已經添加了排除依賴的依賴裏，把須要排除的依賴的座標引進來。
 

 
 

 
 

----3-9 依賴衝突-------------------------------------------------------------------------------------------------------
 

 依賴衝突：
 

A->B->C->X(jar1.0)
 

A->D->X(jar1.1)
 

這是A依賴兩個X的版本，會有衝突。
 

1.短路優先原則
 

bge 新加依賴 2.4
 

nange 新加依賴2.0
 

山雞 因爲短路優先 會是2.0
 

注：eclipse,在pom.xml中添加完依賴後會自動下載
 

 

 
 

 2.若是路徑長度相同的狀況下，則誰先聲明，先解析誰。（若是前面兩個pom.xml都聲明瞭同一個依賴的不一樣版本，第三個pom.xml同時依賴了前兩個pom.xml，則誰的依賴座標在前，就用誰的依賴版本。）
 

上例修改成 nange不依賴bge,shanji同時依賴nange和bge（exclusion去掉），bge座標在前就解析爲2.4
 

 

 
 

---3-10 maven聚合和繼承--------------------------------------------------------------------------------------------------------
 

若是項目D依賴項目C，項目C依賴項目B，項目B依賴項目A，咱們須要一個個安裝這項項目，在Maven中有一種方式能夠將多個項目一次性安裝，這就是聚合的概念。簡單講就是，須要人工屢次操做的，只要Maven能理解，一次性告訴他，他就能幫咱們作這件單調煩人的事情了。——使用
 

maven聚合：聚合其實是對多個項目同時進行作處理，好比編譯、打包等。作法以下：建立一個新的maven項目，用於作其它項目的聚合，而後把pom.xml文件裏的package標籤裏的jar改爲pom，並去掉依賴，而後添加modules把其它項目引進來。
 

 
 

 
 
<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>com.hongxing</groupId>
  <artifactId>aggreation</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>pom</packaging>

  <name>aggreation</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <modules>
    <module>../bge</module>
    <module>../nange</module>
    <module>../shanji</module>
  </modules>
</project>
 

 

pom.xml - run as -maven build : 
 

　　Goals: clean install (刪除target  安裝)
 

 
 
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Build Order:
[INFO] 
[INFO] bge
[INFO] nange
[INFO] shanji
[INFO] aggreation
[INFO] 
[INFO] ------------------------------------------------------------------------
[INFO] Building bge 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-clean-plugin/2.5/maven-clean-plugin-2.5.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-clean-plugin/2.5/maven-clean-plugin-2.5.pom (3.9 kB at 2.4 kB/s)
[INFO] 
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ bge ---
[INFO] Deleting D:\java\workspace\bge\target
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ bge ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory D:\java\workspace\bge\src\main\resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ bge ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to D:\java\workspace\bge\target\classes
[INFO] 
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ bge ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory D:\java\workspace\bge\src\test\resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ bge ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to D:\java\workspace\bge\target\test-classes
[INFO] 
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ bge ---
[INFO] Surefire report directory: D:\java\workspace\bge\target\surefire-reports

-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running com.hongxing.bge.AppTest
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.01 sec

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

[INFO] 
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ bge ---
[INFO] Building jar: D:\java\workspace\bge\target\bge-0.0.1-SNAPSHOT.jar
[INFO] 
[INFO] --- maven-install-plugin:2.4:install (default-install) @ bge ---
[INFO] Installing D:\java\workspace\bge\target\bge-0.0.1-SNAPSHOT.jar to D:\java\localRepository\com\hongxing\bge\0.0.1-SNAPSHOT\bge-0.0.1-SNAPSHOT.jar
[INFO] Installing D:\java\workspace\bge\pom.xml to D:\java\localRepository\com\hongxing\bge\0.0.1-SNAPSHOT\bge-0.0.1-SNAPSHOT.pom
[INFO] 
[INFO] ------------------------------------------------------------------------
[INFO] Building nange 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ nange ---
[INFO] Deleting D:\java\workspace\nange\target
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ nange ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory D:\java\workspace\nange\src\main\resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ nange ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to D:\java\workspace\nange\target\classes
[INFO] 
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ nange ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory D:\java\workspace\nange\src\test\resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ nange ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to D:\java\workspace\nange\target\test-classes
[INFO] 
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ nange ---
[INFO] Surefire report directory: D:\java\workspace\nange\target\surefire-reports

-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running com.hongxing.nange.AppTest
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.013 sec

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

[INFO] 
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ nange ---
[INFO] Building jar: D:\java\workspace\nange\target\nange-0.0.1-SNAPSHOT.jar
[INFO] 
[INFO] --- maven-install-plugin:2.4:install (default-install) @ nange ---
[INFO] Installing D:\java\workspace\nange\target\nange-0.0.1-SNAPSHOT.jar to D:\java\localRepository\com\hongxing\nange\0.0.1-SNAPSHOT\nange-0.0.1-SNAPSHOT.jar
[INFO] Installing D:\java\workspace\nange\pom.xml to D:\java\localRepository\com\hongxing\nange\0.0.1-SNAPSHOT\nange-0.0.1-SNAPSHOT.pom
[INFO] 
[INFO] ------------------------------------------------------------------------
[INFO] Building shanji 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ shanji ---
[INFO] Deleting D:\java\workspace\shanji\target
[INFO] 
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ shanji ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory D:\java\workspace\shanji\src\main\resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.1:compile (default-compile) @ shanji ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to D:\java\workspace\shanji\target\classes
[INFO] 
[INFO] --- maven-resources-plugin:2.6:testResources (default-testResources) @ shanji ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory D:\java\workspace\shanji\src\test\resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ shanji ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to D:\java\workspace\shanji\target\test-classes
[INFO] 
[INFO] --- maven-surefire-plugin:2.12.4:test (default-test) @ shanji ---
[INFO] Surefire report directory: D:\java\workspace\shanji\target\surefire-reports

-------------------------------------------------------
 T E S T S
-------------------------------------------------------
Running com.hongxing.shanji.AppTest
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.016 sec

Results :

Tests run: 1, Failures: 0, Errors: 0, Skipped: 0

[INFO] 
[INFO] --- maven-jar-plugin:2.4:jar (default-jar) @ shanji ---
[INFO] Building jar: D:\java\workspace\shanji\target\shanji-0.0.1-SNAPSHOT.jar
[INFO] 
[INFO] --- maven-install-plugin:2.4:install (default-install) @ shanji ---
[INFO] Installing D:\java\workspace\shanji\target\shanji-0.0.1-SNAPSHOT.jar to D:\java\localRepository\com\hongxing\shanji\0.0.1-SNAPSHOT\shanji-0.0.1-SNAPSHOT.jar
[INFO] Installing D:\java\workspace\shanji\pom.xml to D:\java\localRepository\com\hongxing\shanji\0.0.1-SNAPSHOT\shanji-0.0.1-SNAPSHOT.pom
[INFO] 
[INFO] ------------------------------------------------------------------------
[INFO] Building aggreation 0.0.1-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] 
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ aggreation ---
[INFO] Deleting D:\java\workspace\aggreation\target
[INFO] 
[INFO] --- maven-install-plugin:2.4:install (default-install) @ aggreation ---
[INFO] Installing D:\java\workspace\aggreation\pom.xml to D:\java\localRepository\com\hongxing\aggreation\0.0.1-SNAPSHOT\aggreation-0.0.1-SNAPSHOT.pom
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary:
[INFO] 
[INFO] bge ................................................ SUCCESS [  6.069 s]
[INFO] nange .............................................. SUCCESS [  0.670 s]
[INFO] shanji ............................................. SUCCESS [  0.494 s]
[INFO] aggreation ......................................... SUCCESS [  0.019 s]
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 7.419 s
[INFO] Finished at: 2017-06-29T15:59:41+08:00
[INFO] Final Memory: 19M/139M
[INFO] ------------------------------------------------------------------------
 

 

 
 

繼承：屢次使用到的依賴，好比：單元測試，沒有必要在全部的項目中都引用一下，此時就能夠採用繼承的方式來實現，先來一個父級的POM.XML而後再繼承此POM.XML。
1. packaging 改成pom。
2. dependencyManagement 中並不提取依賴，只進行統一管理。
3. property中定義了junit版本號，以後能夠引用。
4. 父類parent中的main和test沒有意義，能夠刪除。

父類pom：
 

<properties>
 

　　<junit.version>3.8.1</junit.version>
 

</properties>
<dependencyManagement>
   <dependencies>
   <dependency>
     <groupId>junit</groupId>
     <artifactId>junit</artifactId>
     <version>${junit.version}</version>
 

　  <scope>test</scope>
   </dependency>
 </dependencies>
</dependencyManagement>

子類pom：
<parent>
 <groupId>com.hongxin</groupId>
 <artifactId>hongxin-parent</artifactId>
 <version>0.0.1-SNAPSHOT</version>
</parent>
<dependencies>
   <dependency>
     <groupId>junit</groupId>
     <artifactId>junit</artifactId>
   </dependency>
</dependencies>
 

 
 

 
 

 
 

 
 

 
 

 
 

 
 

 
 

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