Java 如何将maven构建文件的各个部分外部化？

我遇到了一个问题：如何将配置文件的版本设置为XML格式。最简单的方法是编写XSLT更新。应用程序的每个版本都有自己的XSLT更新。所有这些更新文件都足够小，可以由IDE管理，特别是它的DIFF工具

由于该项目已经作为Maven2开发，Java逻辑解决方案是通过maven构建文件触发这些更新

这是今天应用一组更新的部分的外观：

<plugin>
  <groupId>org.codehaus.mojo</groupId>
  <artifactId>xml-maven-plugin</artifactId>
  <executions>
    <execution>
    <phase>compile</phase>
      <goals>
        <goal>transform</goal>
      </goals>
    </execution>
  </executions>
  <configuration>
    <transformationSets>
      <transformationSet>
        <dir>config/xsltUpdates/input</dir>
        <stylesheet>config/xsltUpdates/update1-8-3.xsl</stylesheet>
        <outputDir>config/xsltUpdates/update1-8-3</outputDir>
      </transformationSet>
      <transformationSet>
         <dir>config/xsltUpdates/update1-8-3</dir>
         <stylesheet>config/xsltUpdates/update1-8-9.xsl</stylesheet>
         <outputDir>config/xsltUpdates/update1-8-9</outputDir>
      </transformationSet>
      <transformationSet>
        <dir>config/xsltUpdates/update1-8-9</dir>
        <stylesheet>config/xsltUpdates/update1-9-0.xsl</stylesheet>
        <outputDir>config/xsltUpdates/update1-9-0</outputDir>
      </transformationSet>
      <transformationSet>
        <dir>config/xsltUpdates/update1-9-0</dir>
        <stylesheet>config/xsltUpdates/update1-10-0.xsl</stylesheet>
        <outputDir>config/xsltUpdates/update1-10-0</outputDir>
      </transformationSet>
      <transformationSet>
        <dir>config/xsltUpdates/update1-10-0</dir>
        <stylesheet>config/xsltUpdates/update1-10-0-1.xsl</stylesheet>
        <outputDir>config/xsltUpdates/update1-10-0-1</outputDir>
      </transformationSet>
      <transformationSet>
        <dir>config/xsltUpdates/update1-10-0-1</dir>
        <stylesheet>config/xsltUpdates/update1-10-0-2.xsl</stylesheet>
        <outputDir>config/xsltUpdates/update1-10-0-2</outputDir>
      </transformationSet>
      <transformationSet>
        <dir>config/xsltUpdates/update1-10-0-2</dir>
        <stylesheet>config/xsltUpdates/updateCurrent.xsl</stylesheet>
        <outputDir>config/xsltUpdates/output</outputDir>
      </transformationSet>
    </transformationSets>
  </configuration>
  <dependencies>
    <dependency>
      <groupId>net.sf.saxon</groupId>
      <artifactId>saxon</artifactId>
      <version>8.7</version>
    </dependency>
  </dependencies>
</plugin>

org.codehaus.mojo
xml maven插件
编译
使改变
config/xsltUpdates/input
config/xsltUpdates/update1-8-3.xsl
config/xsltUpdates/update1-8-3
config/xsltUpdates/update1-8-3
config/xsltUpdates/update1-8-9.xsl
config/xsltUpdates/update1-8-9
config/xsltUpdates/update1-8-9
config/xsltUpdates/update1-9-0.xsl
config/xsltUpdates/update1-9-0
config/xsltUpdates/update1-9-0
config/xsltUpdates/update1-10-0.xsl
config/xsltUpdates/update1-10-0
config/xsltUpdates/update1-10-0
config/xsltUpdates/update1-10-0-1.xsl
config/xsltUpdates/update1-10-0-1
config/xsltUpdates/update1-10-0-1
config/xsltUpdates/update1-10-0-2.xsl
config/xsltUpdates/update1-10-0-2
config/xsltUpdates/update1-10-0-2
config/xsltUpdates/updateCurrent.xsl
config/xsltUpdates/output
net.sf.saxon
撒克逊人
8.7

我想在一些属性/xml文件导入中具体化有关transformationSet的信息。我的pom.xml文件将更清晰，外部化信息更易于维护

我该怎么做

---

我可以在构建文件中使用一些迭代控制语句吗？有没有从外部文件导入数据的方法？

可能还有其他方法，但您可以在父pom中有一个节

pluginManagement：是一个可以在插件旁边看到的元素。插件管理包含插件元素的方式与此基本相同，不同之处在于它不是为这个特定的项目构建配置插件信息，而是配置从这个项目构建继承的项目构建。但是，这仅配置在子元素的plugins元素中实际引用的插件。孩子们完全有权推翻插件管理的定义

例如：

父项目POM（需要运行mvn安装，以确保您的子项目可见）

4.0.0
org.nkl
父母亲
聚甲醛
0.0.1-快照
org.codehaus.mojo
xml maven插件
编译
使改变
config/xsltUpdates/input
config/xsltUpdates/update1-8-3.xsl
config/xsltUpdates/update1-8-3
config/xsltUpdates/update1-8-3
config/xsltUpdates/update1-8-9.xsl
config/xsltUpdates/update1-8-9
config/xsltUpdates/update1-8-9
config/xsltUpdates/update1-9-0.xsl
config/xsltUpdates/update1-9-0
config/xsltUpdates/update1-9-0
config/xsltUpdates/update1-10-0.xsl
config/xsltUpdates/update1-10-0
config/xsltUpdates/update1-10-0
config/xsltUpdates/update1-10-0-1.xsl
config/xsltUpdates/update1-10-0-1
config/xsltUpdates/update1-10-0-1
config/xsltUpdates/update1-10-0-2.xsl
config/xsltUpdates/update1-10-0-2
config/xsltUpdates/update1-10-0-2
config/xsltUpdates/updateCurrent.xsl
config/xsltUpdates/output
net.sf.saxon
撒克逊人
8.7

儿童项目POM

<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/maven-v4_0_0.xsd">
  <parent>
    <artifactId>parent</artifactId>
    <groupId>org.nkl</groupId>
    <version>0.0.1-SNAPSHOT</version>
  </parent>
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.nkl</groupId>
  <artifactId>child</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <build>
    <plugins>
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>xml-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>
</project>

父母亲
org.nkl
0.0.1-快照
4.0.0
org.nkl
小孩
0.0.1-快照
org.codehaus.mojo
xml maven插件

一些插件允许您使用外部描述符（例如。不幸的是，XMLMaven插件还不是其中之一

一种选择是从XMLMaven插件复制相关目标，并将maven共享io的处理嵌入目标。我一直在寻找自己这样做，以期对各种插件提出请求，使用描述符文件和Locator策略方法来查找描述符。下面是一些修改XMLMaven插件以允许使用描述符的处理。注意，所涉及的文件几乎没有验证，所以它有点脆弱，但它确实有效

1） 创建一个新的maven插件项目（称为xml ext maven插件），该项目具有以下依赖项：

<dependencies>
  <dependency>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>xml-maven-plugin</artifactId>
    <version>1.0-beta-2</version>
  </dependency>
  <dependency>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-assembly-plugin</artifactId>
    <version>2.2-beta-2</version>
  </dependency>
</dependencies>

4） 修改execute（）方法以读取TransformationSet的描述符

public void execute() throws MojoExecutionException, MojoFailureException {
    //insert at start of method to resolve transformationSets fronm descriptors
    if (descriptors != null && descriptors.length > 0) {
        transformationSets = readDescriptors(descriptors);
    }

    ...

5） 实现readDescriptors（），允许您在类路径上或项目中定位描述符（读卡器处理主要从程序集插件的DefaultAssemblyReader中提升）。注意在这个实现中几乎没有验证，一个合适的插件会检查是否设置了值等

private TransformationSet[] readDescriptors(String[] descriptors)
        throws MojoExecutionException {

    List descriptorSets = new ArrayList();
    // add all the existing transformationSets
    if (transformationSets != null && transformationSets.length != 0) {
        descriptorSets.addAll(Arrays.asList(transformationSets));
    }

    for (int i = 0; i < descriptors.length; i++) {
        getLog().info(
                "Reading transformation descriptor: " + descriptors[i]);

        Location location = getLocation(descriptors[i]);

        Reader reader = null;
        try {
            reader = new InputStreamReader(location.getInputStream(),
                    "UTF-8");

            Xpp3Dom dom = Xpp3DomBuilder.build(reader);

            descriptorSets.addAll(parseTransformationSets(dom));
        } catch (IOException e) {
            throw new MojoExecutionException(
                    "Error reading transformation descriptor: "
                            + descriptors[i], e);
        } catch (XmlPullParserException e) {
            throw new MojoExecutionException(
                    "Error parsing transformation descriptor: "
                            + descriptors[i], e);
        } finally {
            IOUtil.close(reader);
        }
    }

    return (TransformationSet[]) descriptorSets
            .toArray(new TransformationSet[descriptorSets.size()]);
}

/**
 * Create transformationSets from the Xpp3Dom.
 * TODO use plexus utilities to resolve these elegantly?
 */
private List parseTransformationSets(Xpp3Dom dom) {
    // TODO validation of the input files!
    Xpp3Dom[] setDoms = dom.getChildren("transformationSet");

    List sets = new ArrayList();
    for (int i = 0; i < setDoms.length; i++) {
        TransformationSet set = new TransformationSet();
        set.setDir(new File(setDoms[i].getChild("dir").getValue()));
        set.setStylesheet(new File(setDoms[i].getChild("stylesheet")
                .getValue()));

        Xpp3Dom outDom = setDoms[i].getChild("outputDir");

        if (outDom != null) {
            set.setOutputDir(new File(outDom.getValue()));
        }

        sets.add(set);
    }
    return sets;
}

7） 重写asAbsoluteFile（）以使用定位器策略解析文件（也允许我们在描述符项目中定义xsl文件）

8） 将插件安装到您的存储库中

9） 创建一个新的maven项目

public void execute() throws MojoExecutionException, MojoFailureException {
    //insert at start of method to resolve transformationSets fronm descriptors
    if (descriptors != null && descriptors.length > 0) {
        transformationSets = readDescriptors(descriptors);
    }

    ...

private TransformationSet[] readDescriptors(String[] descriptors)
        throws MojoExecutionException {

    List descriptorSets = new ArrayList();
    // add all the existing transformationSets
    if (transformationSets != null && transformationSets.length != 0) {
        descriptorSets.addAll(Arrays.asList(transformationSets));
    }

    for (int i = 0; i < descriptors.length; i++) {
        getLog().info(
                "Reading transformation descriptor: " + descriptors[i]);

        Location location = getLocation(descriptors[i]);

        Reader reader = null;
        try {
            reader = new InputStreamReader(location.getInputStream(),
                    "UTF-8");

            Xpp3Dom dom = Xpp3DomBuilder.build(reader);

            descriptorSets.addAll(parseTransformationSets(dom));
        } catch (IOException e) {
            throw new MojoExecutionException(
                    "Error reading transformation descriptor: "
                            + descriptors[i], e);
        } catch (XmlPullParserException e) {
            throw new MojoExecutionException(
                    "Error parsing transformation descriptor: "
                            + descriptors[i], e);
        } finally {
            IOUtil.close(reader);
        }
    }

    return (TransformationSet[]) descriptorSets
            .toArray(new TransformationSet[descriptorSets.size()]);
}

/**
 * Create transformationSets from the Xpp3Dom.
 * TODO use plexus utilities to resolve these elegantly?
 */
private List parseTransformationSets(Xpp3Dom dom) {
    // TODO validation of the input files!
    Xpp3Dom[] setDoms = dom.getChildren("transformationSet");

    List sets = new ArrayList();
    for (int i = 0; i < setDoms.length; i++) {
        TransformationSet set = new TransformationSet();
        set.setDir(new File(setDoms[i].getChild("dir").getValue()));
        set.setStylesheet(new File(setDoms[i].getChild("stylesheet")
                .getValue()));

        Xpp3Dom outDom = setDoms[i].getChild("outputDir");

        if (outDom != null) {
            set.setOutputDir(new File(outDom.getValue()));
        }

        sets.add(set);
    }
    return sets;
}

private Location getLocation(String path) {
    List strategies = new ArrayList();
    strategies.add(new RelativeFileLocatorStrategy(getBasedir()));
    strategies.add(new ClasspathResourceLocatorStrategy());
    strategies.add(new FileLocatorStrategy());
    strategies.add(new URLLocatorStrategy());

    List refStrategies = new ArrayList();
    refStrategies.add(classpathStrategy);

    Locator locator = new Locator();

    locator.setStrategies(strategies);

    Location location = locator.resolve(path);
    return location;
}

protected File asAbsoluteFile(File f) {
    String path = f.getPath();

    // ensure we're getting a path in the form that URL can handle
    if (path != null) {
        path = path.replaceAll("\\\\", "/");
    }
    Location location = getLocation(path);

    if (location == null) {
        //can't find the file, let the parent implementation have a try
        return super.asAbsoluteFile(f);
    }
    try {
        return location.getFile();
    } catch (IOException e) {
        throw new RuntimeException("unable to read file " + f.getPath(), e);
    }
}

<transformationSets>
  <transformationSet>
    <!--the config directory is in the root of the project -->
    <dir>config/xsltUpdates/input</dir>
    <!-- the stylesheet can be in the descriptor project-->
    <stylesheet>/stylesheets/update1-8-3.xsl</stylesheet>       
    <outputDir>config/xsltUpdates/update1-8-3</outputDir>
  </transformationSet>
  <transformationSet>
     <dir>config/xsltUpdates/update1-8-3</dir>
     <stylesheet>/stylesheets/update1-8-9.xsl</stylesheet>
     <outputDir>config/xsltUpdates/update1-8-9</outputDir>
  </transformationSet>
</transformationSets>

<plugin>
  <groupId>org.codehaus.mojo</groupId>
  <artifactId>xml-maven-plugin</artifactId>
  <executions>
    <execution>
      <phase>compile</phase>
      <goals>
        <goal>transform</goal>
      </goals>
    </execution>
  </executions>
  <dependencies>
    <dependency>
      <groupId>name.seller.rich</groupId>
      <artifactId>xml-ext-test-descriptor</artifactId>
      <version>0.0.1</version>
    </dependency>
  </dependencies>
  <configuration>
   <descriptors>
     <!-- will be resolved from xml-ext-test-descriptor -->
     <descriptor>/transformationSet1.xml</descriptor>
   </descriptors>
 </plugin>