Solution for a jar file not findable in the `WEB-I

2019-04-08 22:43发布

问题:

I have a Java application running on Jetty/App Engine/Spring.

After removing some jar files from the pom and putting them in the WEB-INF/lib folder, they are no longer findable - I get numerous "Cannot find symbol" build errors.

I also tried putting the jars in the src/main/resources folder - but the same outcome.

How can I make these jars findable without referencing them in the pom?

UPDATE FOR PASCAL'S QUESTION:

Here are the "unable fo find resource" messages I was receiving:

Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/htmlunit/2.8/htmlunit-2.8.pom
[INFO] Unable to find resource 'htmlunit:htmlunit:pom:2.8' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.com/svn/re
pository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/htmlunit/2.8/htmlunit-2.8.pom
[INFO] Unable to find resource 'htmlunit:htmlunit:pom:2.8' in repository jboss-repo (https://repository.jboss.org/nexus/content/groups
/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/htmlunit/2.8/htmlunit-2.8.pom
[INFO] Unable to find resource 'htmlunit:htmlunit:pom:2.8' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/apache-mime/0.6/apache-mime-0.6.pom
[INFO] Unable to find resource 'htmlunit:apache-mime:pom:0.6' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.com/svn
/repository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/apache-mime/0.6/apache-mime-0.6.pom
[INFO] Unable to find resource 'htmlunit:apache-mime:pom:0.6' in repository jboss-repo (https://repository.jboss.org/nexus/content/gro
ups/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/apache-mime/0.6/apache-mime-0.6.pom
[INFO] Unable to find resource 'htmlunit:apache-mime:pom:0.6' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/commons-codec/1.4/commons-codec-1.4.pom
[INFO] Unable to find resource 'htmlunit:commons-codec:pom:1.4' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.com/s
vn/repository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/commons-codec/1.4/commons-codec-1.4.pom
[INFO] Unable to find resource 'htmlunit:commons-codec:pom:1.4' in repository jboss-repo (https://repository.jboss.org/nexus/content/g
roups/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/commons-codec/1.4/commons-codec-1.4.pom
[INFO] Unable to find resource 'htmlunit:commons-codec:pom:1.4' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/commons-collections/3.2.1/commons-collections-3.2.1.pom
[INFO] Unable to find resource 'htmlunit:commons-collections:pom:3.2.1' in repository maven-gae-repo (http://maven-gae-plugin.googleco
de.com/svn/repository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/commons-collections/3.2.1/commons-collections-3.2.1.pom

[INFO] Unable to find resource 'htmlunit:commons-collections:pom:3.2.1' in repository jboss-repo (https://repository.jboss.org/nexus/c
ontent/groups/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/commons-collections/3.2.1/commons-collections-3.2.1.pom
[INFO] Unable to find resource 'htmlunit:commons-collections:pom:3.2.1' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/commons-logging/1.1.1/commons-logging-1.1.1.pom
[INFO] Unable to find resource 'htmlunit:commons-logging:pom:1.1.1' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.c
om/svn/repository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/commons-logging/1.1.1/commons-logging-1.1.1.pom
[INFO] Unable to find resource 'htmlunit:commons-logging:pom:1.1.1' in repository jboss-repo (https://repository.jboss.org/nexus/conte
nt/groups/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/commons-logging/1.1.1/commons-logging-1.1.1.pom
[INFO] Unable to find resource 'htmlunit:commons-logging:pom:1.1.1' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/cssparser/0.9.5/cssparser-0.9.5.pom
[INFO] Unable to find resource 'htmlunit:cssparser:pom:0.9.5' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.com/svn
/repository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/cssparser/0.9.5/cssparser-0.9.5.pom
[INFO] Unable to find resource 'htmlunit:cssparser:pom:0.9.5' in repository jboss-repo (https://repository.jboss.org/nexus/content/gro
ups/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/cssparser/0.9.5/cssparser-0.9.5.pom
[INFO] Unable to find resource 'htmlunit:cssparser:pom:0.9.5' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/htmlunit-core-js/2.8/htmlunit-core-js-2.8.pom
[INFO] Unable to find resource 'htmlunit:htmlunit-core-js:pom:2.8' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.co
m/svn/repository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/htmlunit-core-js/2.8/htmlunit-core-js-2.8.pom
[INFO] Unable to find resource 'htmlunit:htmlunit-core-js:pom:2.8' in repository jboss-repo (https://repository.jboss.org/nexus/conten
t/groups/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/htmlunit-core-js/2.8/htmlunit-core-js-2.8.pom
[INFO] Unable to find resource 'htmlunit:htmlunit-core-js:pom:2.8' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/httpclient/4.0.1/httpclient-4.0.1.pom
[INFO] Unable to find resource 'htmlunit:httpclient:pom:4.0.1' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.com/sv
n/repository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/httpclient/4.0.1/httpclient-4.0.1.pom
[INFO] Unable to find resource 'htmlunit:httpclient:pom:4.0.1' in repository jboss-repo (https://repository.jboss.org/nexus/content/gr
oups/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/httpclient/4.0.1/httpclient-4.0.1.pom
[INFO] Unable to find resource 'htmlunit:httpclient:pom:4.0.1' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/httpcore/4.0.1/httpcore-4.0.1.pom
[INFO] Unable to find resource 'htmlunit:httpcore:pom:4.0.1' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.com/svn/
repository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/httpcore/4.0.1/httpcore-4.0.1.pom
[INFO] Unable to find resource 'htmlunit:httpcore:pom:4.0.1' in repository jboss-repo (https://repository.jboss.org/nexus/content/grou
ps/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/httpcore/4.0.1/httpcore-4.0.1.pom
[INFO] Unable to find resource 'htmlunit:httpcore:pom:4.0.1' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/httpmime/4.0.1/httpmime-4.0.1.pom
[INFO] Unable to find resource 'htmlunit:httpmime:pom:4.0.1' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.com/svn/
repository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/httpmime/4.0.1/httpmime-4.0.1.pom
[INFO] Unable to find resource 'htmlunit:httpmime:pom:4.0.1' in repository jboss-repo (https://repository.jboss.org/nexus/content/grou
ps/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/httpmime/4.0.1/httpmime-4.0.1.pom
[INFO] Unable to find resource 'htmlunit:httpmime:pom:4.0.1' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/nekohtml/1.9.14/nekohtml-1.9.14.pom
[INFO] Unable to find resource 'htmlunit:nekohtml:pom:1.9.14' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.com/svn
/repository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/nekohtml/1.9.14/nekohtml-1.9.14.pom
[INFO] Unable to find resource 'htmlunit:nekohtml:pom:1.9.14' in repository jboss-repo (https://repository.jboss.org/nexus/content/gro
ups/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/nekohtml/1.9.14/nekohtml-1.9.14.pom
[INFO] Unable to find resource 'htmlunit:nekohtml:pom:1.9.14' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/sac/1.3/sac-1.3.pom
[INFO] Unable to find resource 'htmlunit:sac:pom:1.3' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.com/svn/reposit
ory)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/sac/1.3/sac-1.3.pom
[INFO] Unable to find resource 'htmlunit:sac:pom:1.3' in repository jboss-repo (https://repository.jboss.org/nexus/content/groups/publ
ic)
Downloading: http://repo1.maven.org/maven2/htmlunit/sac/1.3/sac-1.3.pom
[INFO] Unable to find resource 'htmlunit:sac:pom:1.3' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/serializer/2.7.1/serializer-2.7.1.pom
[INFO] Unable to find resource 'htmlunit:serializer:pom:2.7.1' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.com/sv
n/repository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/serializer/2.7.1/serializer-2.7.1.pom
[INFO] Unable to find resource 'htmlunit:serializer:pom:2.7.1' in repository jboss-repo (https://repository.jboss.org/nexus/content/gr
oups/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/serializer/2.7.1/serializer-2.7.1.pom
[INFO] Unable to find resource 'htmlunit:serializer:pom:2.7.1' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/xalan/2.7.1/xalan-2.7.1.pom
[INFO] Unable to find resource 'htmlunit:xalan:pom:2.7.1' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.com/svn/rep
ository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/xalan/2.7.1/xalan-2.7.1.pom
[INFO] Unable to find resource 'htmlunit:xalan:pom:2.7.1' in repository jboss-repo (https://repository.jboss.org/nexus/content/groups/
public)
Downloading: http://repo1.maven.org/maven2/htmlunit/xalan/2.7.1/xalan-2.7.1.pom
[INFO] Unable to find resource 'htmlunit:xalan:pom:2.7.1' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/xercesImpl/2.9.1/xercesImpl-2.9.1.pom
[INFO] Unable to find resource 'htmlunit:xercesImpl:pom:2.9.1' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.com/sv
n/repository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/xercesImpl/2.9.1/xercesImpl-2.9.1.pom
[INFO] Unable to find resource 'htmlunit:xercesImpl:pom:2.9.1' in repository jboss-repo (https://repository.jboss.org/nexus/content/gr
oups/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/xercesImpl/2.9.1/xercesImpl-2.9.1.pom
[INFO] Unable to find resource 'htmlunit:xercesImpl:pom:2.9.1' in repository central (http://repo1.maven.org/maven2)
Downloading: http://maven-gae-plugin.googlecode.com/svn/repository/htmlunit/xml-apis/1.3.04/xml-apis-1.3.04.pom
[INFO] Unable to find resource 'htmlunit:xml-apis:pom:1.3.04' in repository maven-gae-repo (http://maven-gae-plugin.googlecode.com/svn
/repository)
Downloading: https://repository.jboss.org/nexus/content/groups/public/htmlunit/xml-apis/1.3.04/xml-apis-1.3.04.pom
[INFO] Unable to find resource 'htmlunit:xml-apis:pom:1.3.04' in repository jboss-repo (https://repository.jboss.org/nexus/content/gro
ups/public)
Downloading: http://repo1.maven.org/maven2/htmlunit/xml-apis/1.3.04/xml-apis-1.3.04.pom
[INFO] Unable to find resource 'htmlunit:xml-apis:pom:1.3.04' in repository central (http://repo1.maven.org/maven2)

They are all related to htmlunit version 2.8 rather than the gdata library I said earlier had caused the errors.

These are the corresponding htmlunit entries in the pom file for the project I am trying to build:

    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>htmlunit</artifactId>
        <version>2.8</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>apache-mime</artifactId>
        <version>0.6</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>commons-codec</artifactId>
        <version>1.4</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>commons-collections</artifactId>
        <version>3.2.1</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>commons-logging</artifactId>
        <version>1.1.1</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>cssparser</artifactId>
        <version>0.9.5</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>htmlunit-core-js</artifactId>
        <version>2.8</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>httpclient</artifactId>
        <version>4.0.1</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>httpcore</artifactId>
        <version>4.0.1</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>httpmime</artifactId>
        <version>4.0.1</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>nekohtml</artifactId>
        <version>1.9.14</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>sac</artifactId>
        <version>1.3</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>serializer</artifactId>
        <version>2.7.1</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>xalan</artifactId>
        <version>2.7.1</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>xercesImpl</artifactId>
        <version>2.9.1</version>
    </dependency>
    <dependency>
        <groupId>htmlunit</groupId>
        <artifactId>xml-apis</artifactId>
        <version>1.3.04</version>
    </dependency>

As you correctly guessed, the htmlunit that is in my local maven repository does not have pom files. I also can't remember how I installed it. In each subdirectory containing a jar file there no pom file - but instead a file called, for example, htmlunit-2.8.pom.lastUpdated which contains this text:

#Last modified on: Tue Oct 26 13:43:29 BST 2010
#Tue Oct 26 13:43:29 BST 2010
http\://maven-gae-plugin.googlecode.com/svn/repository=1288097006231
https\://repository.jboss.org/nexus/content/groups/public=1288097009578
http\://repo1.maven.org/maven2=1288097009912

You may be asking why I am using version 2.8 - well, it contains some patches that are essential for my project. Version 2.7 builds fine from the maven dependency:

<dependency>
   <groupId>net.sourceforge.htmlunit</groupId>
   <artifactId>htmlunit</artifactId>
   <version>2.7</version>
</dependency>

but when I use this:

<dependency>
   <groupId>net.sourceforge.htmlunit</groupId>
   <artifactId>htmlunit</artifactId>
   <version>2.8</version>
</dependency>

I get an error during the build that says "command line too long":

10/26/10 9:03:27 PM BST: [ERROR]  Standard error from the DataNucleus tool + org.datanucleus.enhancer.DataNucleusEnhancer :
10/26/10 9:03:27 PM BST: [ERROR] --------------------
10/26/10 9:03:27 PM BST: [ERROR] The command line is too long.

回答1:

As I mentioned in a comment below, I want to remove them from the pom because even though they are in my local Maven repository, while maven is building the project it always says it is trying to download each of these local dependencies, adding extra time onto each build cycle.

You aren't showing any trace illustrating the exact problem (this usually helps) but unless your local dependencies are SNAPSHOT dependencies (and that would be a bad choice for manually installed artifacts), I don't think your description of the behavior is accurate.

I was hoping to copy these jars to a location where they will be found by the build process but without Maven trying to download any resources each time.

My guess is that the dependencies are just missing a .pom file, which is what Maven is trying to download. You can tell Maven to generate this pom for you when installing a JAR in your local repository using:

mvn install:install-file -Dfile=your-artifact-1.0.jar \
                         [-DgroupId=org.some.group] \
                         [-DartifactId=your-artifact] \
                         [-Dversion=1.0] \
                         [-Dpackaging=jar] \
                         [-DgeneratePom=true] 

Regardless of how horrible it may seem, I find Maven's behavior here more horrible.

Using system scope dependencies doesn't seem horrible, it is an horrible and discouraged practice and should be avoided in 99,999% of the cases. Quoting the provided link:

system: This dependency is required in some phase of your project's lifecycle, but is system-specific. Use of this scope is discouraged: This is considered an "advanced" kind of feature and should only be used when you truly understand all the ramifications of its use, which can be extremely hard if not actually impossible to quantify. This scope by definition renders your build non-portable. It may be necessary in certain edge cases. The system scope includes the <systemPath> element which points to the physical location of this dependency on the local machine. It is thus used to refer to some artifact expected to be present on the given local machine an not in a repository; and whose path may vary machine-to-machine. The systemPath element can refer to environment variables in its path: ${JAVA_HOME} for instance.

Just use Maven the right way and you won't have problems. With system scoped dependencies (why on earth people keep suggesting to abuse them?!), I predict more troubles later.


As you correctly guessed, the htmlunit that is in my local maven repository does not have pom files. I also can't remember how I installed it.

So I'm not crazy :) Obviously, my suggestion is to fix the problem and to provide the missing .pom files. If you don't want to reinstall the artifacts (so that Maven could generate them), you can create the .pom manually. A simple file like this would suffice:

<project>
  <modelVersion>4.0.0</modelVersion>
  <groupId>ze.groupId</groupId>
  <artifactId>some-artifact-id</artifactId>
  <version>X.Y.Z</version>
</project>

But please, don't switch to system scoped dependencies, this will do more harm than good on the long run.

You may be asking why I am using version 2.8 - well, it contains some patches that are essential for my project.

You certainly have good reasons and I won't even discuss them.

(...) I get an error during the build that says "command line too long":

That's unfortunate, and you should report this problem to datanucleus.



回答2:

<dependency>
    <groupId>org.companyname</groupId>
    <artifactId>artifact</artifactId>
    <version>versionNumber</version>
    <scope>system</scope>
    <systemPath>PATH_TO_YOUR_JAR</systemPath>
</dependency>

Try something like this

Dependencies with the scope system are always available and are not looked up in repository. They are usually used to tell Maven about dependencies which are provided by the JDK or the VM. Thus, system dependencies are especially useful for resolving dependencies on artifacts which are now provided by the JDK, but where available as separate downloads earlier. Typical example are the JDBC standard extensions or the Java Authentication and Authorization Service (JAAS).

A simple example would be:

<project>
  ...
  <dependencies>
    <dependency>
      <groupId>javax.sql</groupId>
      <artifactId>jdbc-stdext</artifactId>
      <version>2.0</version>
      <scope>system</scope>
      <systemPath>${java.home}/lib/rt.jar</systemPath>
    </dependency>
  </dependencies>
  ...
</project>  
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