maven-dependency-plugin插件的使用

　　maven-dependency-plugin是处理与依赖相关的插件。它有很多可用的goal，大部分是和依赖构建、分析和解决相关的goal，这部分goal可以直接用maven的命令操作，例如：mvn dependency:tree、mvn dependency:analyze；这类操作在平时的maven应用中很少会用到。这里主要介绍除此之外的、用得最多的几个操作：copy, copy-dependencies和它们对应的unpack, unpack-dependencies.

　　首先声明插件:

<build>

    <plugins>

        <plugin>

            <groupId>org.apache.maven.plugins</groupId>

            <artifactId>maven-dependency-plugin</artifactId>

            <version>2.8</version>

        </plugin>

    </plugins>

</build>

copy 和 unpack

copy操作可以用来将某个（些）maven artifact(s)拷贝到某个目录下。添加phase和goal如下：

<build>

    <plugins>

        <plugin>

            <groupId>org.apache.maven.plugins</groupId>

            <artifactId>maven-dependency-plugin</artifactId>

            <version>2.8</version>

            <executions>

                <execution>

                    <phase>package</phase>

                    <goals>

                        <goal>copy</goal>

                    </goals>

                </execution>

            </executions>

        </plugin>

    </plugins>

</build>

然后就是配置，copy可以的配置的项比较多，详细的请参考：copy配置。下面是一些常用项说明：

Name Type Since Description

artifactItems	`List`	`1.0`	Collection of ArtifactItems to work on. (ArtifactItem contains groupId, artifactId, version, type, classifier, outputDirectory, destFileName and overWrite.) See Usage for details.
outputDirectory	`File`	`1.0`	Default output location used for mojo, unless overridden in ArtifactItem. Default value is: `${project.build.directory}/dependency`. User property is: `outputDirectory`.
prependGroupId	`boolean`	`2.7`	Prepend artifact groupId during copy Default value is: `false`. User property is: `mdep.prependGroupId`.

prependGroupId: 用来指示拷出来的library名字需要不需要加上groupId，默认是不加
outputDirectory: 用来指定拷出后Libraries的存放地

这里除了artifactItems没有默认值，需要指定外，所有其他的选项都可以被忽略：

<configuration>

    <artifactItems>

        <artifactItem>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <version>4.11</version>

        </artifactItem>

    </artifactItems>

</configuration>

以上配置会将junit包拷到target/dependency目录下，文件名为：junit-4.11.jar。

如果想把它拷到lib目录下，可以如下配置：

<configuration>

    <artifactItems>

        <artifactItem>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <version>4.11</version>

        </artifactItem>

    </artifactItems>

    <outputDirectory>lib</outputDirectory>

</configuration>

或者:

<configuration>

    <artifactItems>

        <artifactItem>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <version>4.11</version>

            <outputDirectory>lib</outputDirectory>

        </artifactItem>

    </artifactItems>

</configuration>

根据上面的说明，artifactItem里可以有以下几个参数：

groupId
artifactId
version
type
classifier
outputDirectory
destFileName
overWrite

同样的参数，artifactItem里的优先级更高，例如：

<configuration>

    <artifactItems>

        <artifactItem>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <version>4.11</version>

        </artifactItem>

        <artifactItem>

            <groupId>org.slf4j</groupId>

            <artifactId>slf4j-log4j12</artifactId>

            <version>1.7.7</version>

            <outputDirectory>lib2</outputDirectory>

        </artifactItem>

    </artifactItems>

    <outputDirectory>lib</outputDirectory>

</configuration>

其中junit会拷到lib目录下，因为它没有定义自己的outputDirectory；slf4j-log4j12会拷到lib2下，因为它定义了自己的outputDirectory。

unpack和copy类似，只不过它会把拷来的包解开，例如：

<executions>

    <execution>

        <phase>package</phase>

        <goals>

            <goal>unpack</goal>

        </goals>

    </execution>

</executions>

<configuration>

    <artifactItems>

        <artifactItem>

            <groupId>junit</groupId>

            <artifactId>junit</artifactId>

            <version>4.11</version>

        </artifactItem>

        <artifactItem>

            <groupId>org.slf4j</groupId>

            <artifactId>slf4j-log4j12</artifactId>

            <version>1.7.7</version>

            <outputDirectory>lib2</outputDirectory>

        </artifactItem>

    </artifactItems>

    <outputDirectory>lib</outputDirectory>

</configuration>

则junit和slf4j-log4j12拷完以后，放到lib和lib2下的不再是Jar包，还是Jar包里的内容。

copy-dependencies 和 unpack-dependencies

上面介绍的copy 和 unpack操作是由要拷某个包，这个包需要具体指定要拷哪个包，与当前工程的依赖没有关系。copy-dependencies和它有点类似，但是它是用来拷当前工程的依赖包的，典型的，例如我们有一个web应用，当打成war包的时候，它所有的依赖也需要被打到应用中。

copy-dependencies的参数有很多，详细的可以参考：copy-dependencies Doc，但是几乎所有都有默认值。所以一个最简单的定义如下：

<plugin>

    <groupId>org.apache.maven.plugins</groupId>

    <artifactId>maven-dependency-plugin</artifactId>

    <version>2.8</version>

    <executions>

        <execution>

            <phase>package</phase>

            <goals>

                <goal>copy-dependencies</goal>

            </goals>

        </execution>

    </executions>

</plugin>

这里没有指定任何配置，所有的参数都用默认值，则当前工程的所有依赖（直接、间接的）都会被拷到target/dependency目录下。

也可以使用outputDirectory指定存放在。另外，以下几个参数可以控制哪些依赖将被拷出（或排除）：

Name Type Since Description

excludeArtifactIds	`String`	`2.0`	Comma separated list of Artifact names to exclude. User property is: `excludeArtifactIds`.
excludeClassifiers	`String`	`2.0`	Comma Separated list of Classifiers to exclude. Empty String indicates don't exclude anything (default). User property is: `excludeClassifiers`.
excludeGroupIds	`String`	`2.0`	Comma separated list of GroupId Names to exclude. User property is: `excludeGroupIds`.
excludeScope	`String`	`2.0`	Scope to exclude. An Empty string indicates no scopes (default). User property is: `excludeScope`.
excludeTransitive	`boolean`	`2.0`	If we should exclude transitive dependencies Default value is: `false`. User property is: `excludeTransitive`.
excludeTypes	`String`	`2.0`	Comma Separated list of Types to exclude. Empty String indicates don't exclude anything (default). User property is: `excludeTypes`.
includeArtifactIds	`String`	`2.0`	Comma separated list of Artifact names to include. User property is: `includeArtifactIds`.
includeClassifiers	`String`	`2.0`	Comma Separated list of Classifiers to include. Empty String indicates include everything (default). User property is: `includeClassifiers`.
includeGroupIds	`String`	`2.0`	Comma separated list of GroupIds to include. User property is: `includeGroupIds`.
includeScope	`String`	`2.0`	Scope to include. An Empty string indicates all scopes (default). The scopes being interpreted are the scopes as Maven sees them, not as specified in the pom. In summary: `runtime` scope gives runtime and compile dependencies, `compile` scope gives compile, provided, and system dependencies, `test` (default) scope gives all dependencies, `provided` scope just gives provided dependencies, `system` scope just gives system dependencies. User property is: `includeScope`.
includeTypes	`String`	`2.0`	Comma Separated list of Types to include. Empty String indicates include everything (default). User property is: `includeTypes`.

例如当前工程有以下依赖：

<dependencies>

    <dependency>

        <groupId>junit</groupId>

        <artifactId>junit</artifactId>

        <version>4.11</version>

        <scope>test</scope>

    </dependency>

    <dependency>

        <groupId>org.slf4j</groupId>

        <artifactId>slf4j-log4j12</artifactId>

        <version>1.7.7</version>

        <scope>test</scope>

    </dependency>

    <dependency>

        <groupId>org.apache.camel</groupId>

        <artifactId>camel-script</artifactId>

        <version>2.13.2</version>

    </dependency>

    <dependency>

        <groupId>org.apache.camel</groupId>

        <artifactId>camel-spring</artifactId>

        <version>2.13.2</version>

    </dependency>

    <dependency>

        <groupId>org.apache.camel</groupId>

        <artifactId>camel-xstream</artifactId>

        <version>2.13.2</version>

    </dependency>

    <dependency>

        <groupId>org.springframework</groupId>

        <artifactId>spring-jms</artifactId>

        <version>3.2.4.RELEASE</version>

    </dependency>

    <dependency>

        <groupId>org.springframework</groupId>

        <artifactId>spring-tx</artifactId>

        <version>3.2.4.RELEASE</version>

    </dependency>

    <dependency>

        <groupId>org.apache.activemq</groupId>

        <artifactId>activemq-all</artifactId>

        <version>5.10.0</version>

    </dependency>

    <dependency>

        <groupId>com.thoughtworks.xstream</groupId>

        <artifactId>xstream</artifactId>

        <version>1.4.7</version>

    </dependency>

    <dependency>

        <groupId>org.ogce</groupId>

        <artifactId>xpp3</artifactId>

        <version>1.1.6</version>

    </dependency>

</dependencies>

要排除所有scope为test的依赖：

<plugin>

    <groupId>org.apache.maven.plugins</groupId>

    <artifactId>maven-dependency-plugin</artifactId>

    <version>2.8</version>

    <executions>

        <execution>

            <phase>package</phase>

            <goals>

                <goal>copy-dependencies</goal>

            </goals>

        </execution>

    </executions>

    <configuration>

        <includeScope>compile</includeScope>

    </configuration>

</plugin>

注意：这里不能<excludeScope>test</excludeScope>，这样会把所有compile级别的也排除。看下图：

Copied From: Dependencies Scopes

scope/phase->	compile	test	run	assembly
compile	U	U	U	U
provided	U	!	!	!
runtime	!	U	U	U
test	!	U	!	!

说明：最左侧是表示dependency的scope级别，顶行表示maven的阶段，可以看出：compile级别的dependency会在所有阶段都被使用。

要排除所有camel的依赖，如下：

<configuration>

    <excludeGroupIds>org.apache.camel</excludeGroupIds>

</configuration>

要排除除camel-spring外的所有其他依赖如下：

<configuration>

    <includeArtifactIds>camel-spring</includeArtifactIds>

</configuration>

转载:http://liugang594.iteye.com/blog/2093082