无法在 com.itextpdf:itext7-core:pom:RELEASE 收集依赖项

Question

I am trying to create a pdf report using itextpdf library. As it is instructed in the official documentation , I did add the following dependency in my pom.xml :

<properties>
   <itext.version>RELEASE</itext.version>
</properties>
<dependencies>
    <!-- add all iText 7 modules -->
    <dependency>
        <groupId>com.itextpdf</groupId>
        <artifactId>itext7-core</artifactId>
        <version>${itext.version}</version>
        <type>pom</type>
    </dependency>
</dependencies>

To make sure everything is neat and clean, I deleted my .m2/repository directory $rm -R .m2/repository and did run afterwwards $mvn clean compile in my project home directory. I got then the following error :

org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal on project business-project: Could not resolve dependencies for project myproject:business-project:jar:1.1-SNAPSHOT: Failed to collect dependencies at com.itextpdf:itext7-core:pom:RELEASE
    at org.apache.maven.lifecycle.internal.LifecycleDependencyResolver.getDependencies (LifecycleDependencyResolver.java:269)
    at org.apache.maven.lifecycle.internal.LifecycleDependencyResolver.resolveProjectDependencies (LifecycleDependencyResolver.java:147)
    at org.apache.maven.lifecycle.internal.MojoExecutor.ensureDependenciesAreResolved (MojoExecutor.java:248)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:202)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:156)
    at org.apache.maven.lifecycle.internal.MojoExecutor.execute (MojoExecutor.java:148)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:117)
    at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
    at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
    at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
    at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
    at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
    at org.apache.maven.cli.MavenCli.execute (MavenCli.java:957)
    at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:289)
    at org.apache.maven.cli.MavenCli.main (MavenCli.java:193)
    at sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke (Method.java:498)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:282)
    at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:225)
    at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:406)
    at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:347)
Caused by: org.apache.maven.project.DependencyResolutionException: Could not resolve dependencies for project myproject:business-project:jar:1.1-SNAPSHOT: Failed to collect dependencies at com.itextpdf:itext7-core:pom:RELEASE

This the output of $mvn dependency:tree :

[INFO] -------------------< myproject:business-project >--------------------
[INFO] Building Business Layer 1.1-SNAPSHOT                        [3/4]
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] Reactor Summary for myproject 1.1-SNAPSHOT:
[INFO] 
[INFO] my project ......................................... SUCCESS [  0.921 s]
[INFO] DB .......................................... SUCCESS [  0.108 s]
[INFO] Business Layer .............................. FAILURE [  0.234 s]
[INFO] Web Application ............................. SKIPPED
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  1.662 s
[INFO] Finished at: 2020-02-21T20:07:06+01:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project business-project: Could not resolve dependencies for project myproject:business-project:jar:1.1-SNAPSHOT: Failed to collect dependencies at com.itextpdf:itext7-core:pom:RELEASE: Failed to read artifact descriptor for com.itextpdf:itext7-core:pom:RELEASE: Failed to resolve version for com.itextpdf:itext7-core:pom:RELEASE: Could not find metadata com.itextpdf:itext7-core/maven-metadata.xml in local (/Users/MyComputer/.m2/repository) -> [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
[ERROR] 
[ERROR] After correcting the problems, you can resume the build with the command
[ERROR]   mvn <args> -rf :business-project

Running $mvn -v I get :

Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)
Maven home: /usr/local/Cellar/maven/3.6.3/libexec
Java version: 1.8.0_101, vendor: Oracle Corporation, runtime: /Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre
Default locale: de_DE, platform encoding: UTF-8
OS name: "mac os x", version: "10.14.3", arch: "x86_64", family: "mac"

My nexus server configured in my settings.xml :

<mirrors>

        <mirror>
                                               <id>public</id>
                                               <mirrorOf>*</mirrorOf>
                                               <name>Central Repositories of internal repository manager Nexus</name>
                                                <url>http://nexus-server:8081/nexus/content/repositories/public</url>
                               </mirror>
    </mirrors>

How can I fix this problem please? Thank you.

Answer 1

I don't understand exactly what you are trying to do but based on the given information I suppose you are trying to import the pom file as a so called BOM (Bill Of Material) . The issue you have is that you are trying to define a pom type as a dependency which will not work cause it is nothing what you can put on the classpath. Furthermore the given version, which you have defined via the property does simply not exist in Central repository .

The trick is to go via dependencyManagement like this:

<dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>com.itextpdf</groupId>
        <artifactId>itext7-core</artifactId>
        <version>7.1.10</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
   </dependencies>
</dependencyManagement>

Afterwards you can use now the dependencies which have been defined in that BOM file as this:

<dependencies>
  <dependency>
      <groupId>com.itextpdf</groupId>
      <artifactId>barcodes</artifactId>
  </dependency>
</dependencies>

All of the dependencies in that bom can now simply being used by defining them without the version which is controlled by the bom file in the dependencyManagement . This is an elegant way to manage dependencies at a single location via the bom file. You only need to change the version of the bom file and that's it.