给定一个带有父 POM 的 maven 项目 - 主要包括插件和依赖版本 - 我如何生成一个 POM，它从父级获取信息，将其放入子级并删除对父级的引用？
理想情况下，这将使用 maven-assembly-plugin 完成。
更新：我需要自动完成，因为手动操作很无聊且乏味。
更新 2：我正在为外部准备源代码，并且只想交付一个项目，而不是整个家庭。
【问题讨论】：
不久前我遇到了类似的问题，您可以通过定义一个新的 Maven 插件来执行以下操作来避免 Maven 替换属性和解析路径等。
这是我用来证明自己的过程的一些测试代码，您显然需要将其包装在 Maven 插件中并将其绑定到您的过程的某个阶段。解析后的 pom 默认输出到名称为resolved-pom.xml 的输出目录（即目标），这两个属性可以通过设置“outputDir”和/或“pomfileName”属性用通常的Maven插件配置方法覆盖.
package name.seller.rich;
import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Writer;
import java.util.Stack;
import org.apache.maven.artifact.Artifact;
import org.apache.maven.artifact.resolver.ArtifactNotFoundException;
import org.apache.maven.artifact.resolver.ArtifactResolutionException;
import org.apache.maven.model.Model;
import org.apache.maven.model.io.xpp3.MavenXpp3Reader;
import org.apache.maven.plugin.AbstractMojo;
import org.apache.maven.plugin.MojoExecutionException;
import org.apache.maven.plugin.MojoFailureException;
import org.apache.maven.project.MavenProject;
import org.apache.maven.project.inheritance.ModelInheritanceAssembler;
import org.codehaus.plexus.util.xml.pull.XmlPullParserException;
/**
* @goal output-project
* @phase process-resources
* @requiresProject true
*/
public class OutputResolvedProjectMojo extends AbstractMojo {
/**
* Used to look up overlay the parent models on the project's model.
*
* @parameter expression=
* "${component.org.apache.maven.project.inheritance.ModelInheritanceAssembler}"
* @required
* @readonly
*/
private ModelInheritanceAssembler modelInheritanceAssembler;
/**
* Used to look up Artifacts in the remote repository.
*
* @parameter expression=
* "${component.org.apache.maven.artifact.factory.ArtifactFactory}"
* @required
* @readonly
*/
protected org.apache.maven.artifact.factory.ArtifactFactory factory;
/**
* Used to look up Artifacts in the remote repository.
*
* @parameter expression=
* "${component.org.apache.maven.artifact.resolver.ArtifactResolver}"
* @required
* @readonly
*/
protected org.apache.maven.artifact.resolver.ArtifactResolver artifactResolver;
/**
* List of Remote Repositories used by the resolver
*
* @parameter expression="${project.remoteArtifactRepositories}"
* @readonly
* @required
*/
protected java.util.List remoteRepos;
/**
* Location of the local repository.
*
* @parameter expression="${localRepository}"
* @readonly
* @required
*/
protected org.apache.maven.artifact.repository.ArtifactRepository local;
/**
* @parameter expression="${project}"
* @required
* @readonly
*/
private MavenProject mavenProject;
/**
* The directory to output the resolved project to.
*
* @parameter expression="${project.build.directory}"
*/
private File outputDir;
/**
* The directory to output the resolved project to.
*
* @parameter expression="resolved-pom.xml"
*/
private String pomfileName;
public void execute() throws MojoExecutionException, MojoFailureException {
MavenProject parentProject = mavenProject.getParent();
// get the unresolved project by reading the file
MavenProject bareProject = readBareProject(mavenProject.getFile());
Stack hierarchy = new Stack();
hierarchy.push(bareProject);
try {
while (parentProject != null) {
try {
// get Maven to resolve the parent artifact (download if
// needed)
Artifact pomArtifact = this.factory.createArtifact(
parentProject.getGroupId(), parentProject
.getArtifactId(), parentProject
.getVersion(), "", "pom");
artifactResolver.resolve(pomArtifact, this.remoteRepos,
this.local);
// get the file from the local repository and read the bare
// project
File parentPomFile = pomArtifact.getFile();
parentProject = readBareProject(parentPomFile);
hierarchy.push(parentProject);
parentProject = parentProject.getParent();
} catch (ArtifactResolutionException e) {
getLog().error("can't resolve parent pom", e);
} catch (ArtifactNotFoundException e) {
getLog().error("can't resolve parent pom", e);
}
}
// merge each model starting with the oldest ancestors
MavenProject currentParent = (MavenProject) hierarchy.pop();
MavenProject currentProject = null;
while (hierarchy.size() != 0) {
currentProject = (MavenProject) hierarchy.pop();
modelInheritanceAssembler.assembleModelInheritance(
currentProject.getModel(), currentParent.getModel());
currentParent = currentProject;
}
// spit the merged model to the output file.
Writer writer = getWriter(outputDir, pomfileName);
if (writer != null) {
currentProject.writeModel(writer);
writer.close();
}
} catch (IOException e) {
getLog().error("can't write resolved pom", e);
}
}
/**
* Creates and returns a writer for outputting the project to a pom file.
*
* @param logDir
* the directory to output the file to.
* @param logFileName
* name of the log file
* @return the writer.
* @throws IOException
* if the writer cannot be created.
*/
private Writer getWriter(final File logDir, final String logFileName)
throws IOException {
if (!logDir.exists()) {
logDir.mkdirs();
}
File pomLog = new File(logDir, logFileName);
if (!pomLog.exists()) {
pomLog.createNewFile();
}
return new FileWriter(pomLog);
}
/**
* Read the mavenProject without resolving any inherited settings.
*
* @return the MavenProject for the project's POM
* @throws MojoExecutionException
* if the POM can't be parsed.
*/
MavenProject readBareProject(final File file) {
MavenXpp3Reader reader = new MavenXpp3Reader();
Model model = null;
try {
model = reader.read(new FileReader(file));
} catch (IOException e) {
getLog().error("can't read pom file", e);
} catch (XmlPullParserException e) {
getLog().error("can't read pom file", e);
}
return new MavenProject(model);
}
}
【讨论】：
mvn help:effective-pom 会做你需要的吗？您可以使用-Doutput=new-pom.xml 将输出发送到文件。
【讨论】：
如果您不想要父母，您可以尝试 BOM（材料清单）模式并在您的依赖管理部分中选择要导入的 pom。
由于您不希望引用其他任何内容，因此您需要构建一个应用程序来解析来自“父母”的 xml，然后将它们写入依赖项部分的目标 pom 文件。我不认为有任何插件可以做你想做的事，因为它似乎违背了 maven 应该如何帮助你的核心。 maven 的全部意义在于，您可以使用继承或使用导入范围导入所有依赖项。
另一种选择，但我认为您已将其排除在外，是单独维护可发布的 POM 文件。虽然我认为如果您参考 LATEST 或 SNAPSHOTS 然后使用发布插件将它们解析为已发布版本，您可能会发现更轻松。
【讨论】：