Maven nar 插件:nar 文件不在依赖项目的类路径中

Question

我有一个用 C 编写的 JNI 共享库和一个 maven 项目中的相应 Java 类，还有一个在另一个项目中使用该类的应用程序。我使用 nar-maven-plugin 来处理 JNI。 版本： Maven 3.6.0 爪哇 12 NAR 插件 3.6.0 我以 nar-maven-plugin 附带的集成测试 3 和 4 为例。 对于它 3，我刚刚将 POM 更新为独立并与 Java 12 一起使用：

<?xml version="1.0" encoding="UTF-8"?>
<!--
#%L
Native ARchive plugin for Maven
%%
Copyright (C) 2002 - 2014 NAR Maven Plugin developers.
%%
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
#L%
-->
<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.github.maven-nar</groupId>
<artifactId>it0003-jni</artifactId>
<packaging>nar</packaging>
<name>NAR JNI Test</name>
<version>1.0-SNAPSHOT</version>
<description>
Simple JNI Library
</description>
<url>http://maven.apache.org/</url>
<properties>
<skipTests>true</skipTests>
<maven-compiler.version>3.8.1</maven-compiler.version>
<surefire.version>2.22.2</surefire.version>
<java.version>12</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
</properties>  
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<defaultGoal>install</defaultGoal>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven-compiler.version}</version>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
<compilerArgs>
<arg>-Xlint</arg>
<arg>-h</arg>
<arg>${project.build.directory}/nar/javah-include</arg>
</compilerArgs>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>${surefire.version}</version>
<configuration>
<excludes>
<exclude>**/*Test.java</exclude>
</excludes>
<argLine>
<!-- - -illegal-access=permit-->
</argLine>
</configuration>
</plugin>
<plugin>
<groupId>com.github.maven-nar</groupId>
<artifactId>nar-maven-plugin</artifactId>
<version>3.6.0</version>
<extensions>true</extensions>
<configuration>
<cpp>
<debug>true</debug>
</cpp>
<c>
<testOptions>
<testOption>-DTESTOPT="this is a nar-testCompile flag"</testOption>
</testOptions>
</c>
<libraries>
<library>
<type>jni</type>
<narSystemPackage>it0003</narSystemPackage>
<linkCPP>false</linkCPP>
</library>
</libraries>
<javah>
<includes>
<include></include>
</includes>
</javah>
<tests>
<test>
<name>HelloWorld</name>
</test>
</tests>
</configuration>
<executions> 
<execution>
<id>default-nar-javah</id>
<phase>none</phase>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>

我在这个项目上运行mvn install，它安装在我的.m2目录中

/home/karsten/.m2/repository/com/github/maven-nar/it0003-jni/:
total 0
drwxr-xr-x 1 karsten karsten 4096 Sep 27 12:20 1.0-SNAPSHOT
-rw-r--r-- 1 karsten karsten  288 Sep 27 12:21 maven-metadata-local.xml
/home/karsten/.m2/repository/com/github/maven-nar/it0003-jni/1.0-SNAPSHOT:
total 20
-rw-r--r-- 1 karsten karsten  250 Sep 27 12:21 _remote.repositories
-rw-r--r-- 1 karsten karsten 3097 Sep 27 12:21 it0003-jni-1.0-SNAPSHOT-amd64-Linux-gpp-jni.nar
-rw-r--r-- 1 karsten karsten 4570 Sep 27 12:21 it0003-jni-1.0-SNAPSHOT.nar
-rw-r--r-- 1 karsten karsten 4086 Sep 27 12:21 it0003-jni-1.0-SNAPSHOT.pom
-rw-r--r-- 1 karsten karsten  925 Sep 27 12:21 maven-metadata-local.xml

并且it0003-jni-1.0-SNAPSHOT.nar包含

META-INF/MANIFEST.MF
META-INF/
META-INF/nar/
META-INF/nar/com.github.maven-nar/
META-INF/nar/com.github.maven-nar/it0003-jni/
it0003/
META-INF/maven/
META-INF/maven/com.github.maven-nar/
META-INF/maven/com.github.maven-nar/it0003-jni/
META-INF/nar/com.github.maven-nar/it0003-jni/nar.properties
it0003/HelloWorldJNI.class
it0003/NarSystem.class
META-INF/maven/com.github.maven-nar/it0003-jni/pom.xml
META-INF/maven/com.github.maven-nar/it0003-jni/pom.properties

现在我使用它 4 的精简版本来测试它，这是 Java 文件src/main/java/it0004/Hello.java

package it0004;
import it0003.HelloWorldJNI;
public class Hello {
public static void hello()
{
HelloWorldJNI.sayHello();
}
}

而 POM 是

<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">
<modelVersion>4.0.0</modelVersion>
<properties>
<java.version>12</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<maven-compiler.version>3.8.1</maven-compiler.version>
<maven-source.version>2.0.4</maven-source.version>
<nar-plugin.version>3.6.0</nar-plugin.version>
</properties>
<groupId>mygroup</groupId>
<artifactId>myit0004</artifactId>
<packaging>jar</packaging>
<version>1.0.0</version>
<name>Java dependency test</name>
<dependencies>
<dependency>
<groupId>com.github.maven-nar</groupId>
<artifactId>it0003-jni</artifactId>
<version>1.0-SNAPSHOT</version>
<type>nar</type>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven-compiler.version}</version>
<configuration>
<source>${java.version}</source>
<target>${java.version}</target>
<compilerArgs>
<arg>-Xlint</arg>
</compilerArgs>
</configuration>
</plugin>
</plugins>
</build>
</project>

请注意，此 POM 仅处理编译。依赖关系是用<type>nar</type>指定的，以便找到依赖关系。但是 nar 文件不在类路径中，因此编译失败。mvn -X compile的输出包含

[INFO]
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ myit0004 ---
[DEBUG] Dependency collection stats: {ConflictMarker.analyzeTime=428200, ConflictMarker.markTime=241300, ConflictMarker.nodeCount=118, ConflictIdSorter.graphTime=137600, ConflictIdSorter.topsortTime=62600, ConflictIdSorter.conflictIdCount=45, ConflictIdSorter.conflictIdCycleCount=0, ConflictResolver.totalTime=4391200, ConflictResolver.conflictItemCount=72, DefaultDependencyCollector.collectTime=419330500, DefaultDependencyCollector.transformTime=5343800}
[DEBUG] org.apache.maven.plugins:maven-compiler-plugin:jar:3.8.1:
[DEBUG]    org.apache.maven:maven-plugin-api:jar:3.0:compile
[DEBUG]       org.apache.maven:maven-model:jar:3.0:compile
[DEBUG]       org.sonatype.sisu:sisu-inject-plexus:jar:1.4.2:compile
[DEBUG]          org.sonatype.sisu:sisu-inject-bean:jar:1.4.2:compile
[DEBUG]             org.sonatype.sisu:sisu-guice:jar:noaop:2.1.7:compile
[DEBUG]    org.apache.maven:maven-artifact:jar:3.0:compile
[DEBUG]       org.codehaus.plexus:plexus-utils:jar:2.0.4:compile
[DEBUG]    org.apache.maven:maven-core:jar:3.0:compile
[DEBUG]       org.apache.maven:maven-settings:jar:3.0:compile
[DEBUG]       org.apache.maven:maven-settings-builder:jar:3.0:compile
[DEBUG]       org.apache.maven:maven-repository-metadata:jar:3.0:compile
[DEBUG]       org.apache.maven:maven-model-builder:jar:3.0:compile
[DEBUG]       org.apache.maven:maven-aether-provider:jar:3.0:runtime
[DEBUG]       org.sonatype.aether:aether-impl:jar:1.7:compile
[DEBUG]          org.sonatype.aether:aether-spi:jar:1.7:compile
[DEBUG]       org.sonatype.aether:aether-api:jar:1.7:compile
[DEBUG]       org.sonatype.aether:aether-util:jar:1.7:compile
[DEBUG]       org.codehaus.plexus:plexus-interpolation:jar:1.14:compile
[DEBUG]       org.codehaus.plexus:plexus-classworlds:jar:2.2.3:compile
[DEBUG]       org.codehaus.plexus:plexus-component-annotations:jar:1.7.1:compile
[DEBUG]       org.sonatype.plexus:plexus-sec-dispatcher:jar:1.3:compile
[DEBUG]          org.sonatype.plexus:plexus-cipher:jar:1.4:compile
[DEBUG]    org.apache.maven.shared:maven-shared-utils:jar:3.2.1:compile
[DEBUG]       commons-io:commons-io:jar:2.5:compile
[DEBUG]    org.apache.maven.shared:maven-shared-incremental:jar:1.1:compile
[DEBUG]    org.codehaus.plexus:plexus-java:jar:0.9.10:compile
[DEBUG]       org.ow2.asm:asm:jar:6.2:compile
[DEBUG]       com.thoughtworks.qdox:qdox:jar:2.0-M9:compile
[DEBUG]    org.codehaus.plexus:plexus-compiler-api:jar:2.8.4:compile
[DEBUG]    org.codehaus.plexus:plexus-compiler-manager:jar:2.8.4:compile
[DEBUG]    org.codehaus.plexus:plexus-compiler-javac:jar:2.8.4:runtime
[DEBUG] Created new class realm plugin>org.apache.maven.plugins:maven-compiler-plugin:3.8.1
[DEBUG] Importing foreign packages into class realm plugin>org.apache.maven.plugins:maven-compiler-plugin:3.8.1
[DEBUG]   Imported:  < maven.api
[DEBUG] Populating class realm plugin>org.apache.maven.plugins:maven-compiler-plugin:3.8.1
[DEBUG]   Included: org.apache.maven.plugins:maven-compiler-plugin:jar:3.8.1
[DEBUG]   Included: org.sonatype.sisu:sisu-inject-bean:jar:1.4.2
[DEBUG]   Included: org.sonatype.sisu:sisu-guice:jar:noaop:2.1.7
[DEBUG]   Included: org.codehaus.plexus:plexus-utils:jar:2.0.4
[DEBUG]   Included: org.sonatype.aether:aether-util:jar:1.7
[DEBUG]   Included: org.codehaus.plexus:plexus-interpolation:jar:1.14
[DEBUG]   Included: org.codehaus.plexus:plexus-component-annotations:jar:1.7.1
[DEBUG]   Included: org.sonatype.plexus:plexus-sec-dispatcher:jar:1.3
[DEBUG]   Included: org.sonatype.plexus:plexus-cipher:jar:1.4
[DEBUG]   Included: org.apache.maven.shared:maven-shared-utils:jar:3.2.1
[DEBUG]   Included: commons-io:commons-io:jar:2.5
[DEBUG]   Included: org.apache.maven.shared:maven-shared-incremental:jar:1.1
[DEBUG]   Included: org.codehaus.plexus:plexus-java:jar:0.9.10
[DEBUG]   Included: org.ow2.asm:asm:jar:6.2
[DEBUG]   Included: com.thoughtworks.qdox:qdox:jar:2.0-M9
[DEBUG]   Included: org.codehaus.plexus:plexus-compiler-api:jar:2.8.4
[DEBUG]   Included: org.codehaus.plexus:plexus-compiler-manager:jar:2.8.4
[DEBUG]   Included: org.codehaus.plexus:plexus-compiler-javac:jar:2.8.4
[DEBUG] Configuring mojo org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile from plugin realm ClassRealm[plugin>org.apache.maven.plugins:maven-compiler-plugin:3.8.1, parent: jdk.internal.loader.ClassLoaders$AppClassLoader@446cdf90]
[DEBUG] Configuring mojo 'org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile' with basic configurator -->
[DEBUG]   (f) basedir = /home/karsten/svn/myit0004
[DEBUG]   (f) buildDirectory = /home/karsten/svn/myit0004/target
[DEBUG]   (f) compilePath = [/home/karsten/svn/myit0004/target/classes]
[DEBUG]   (f) compileSourceRoots = [/home/karsten/svn/myit0004/src/main/java]
[DEBUG]   (f) compilerArgs = [-Xlint]
[DEBUG]   (f) compilerId = javac
[DEBUG]   (f) debug = true
[DEBUG]   (f) encoding = UTF-8
[DEBUG]   (f) failOnError = true
[DEBUG]   (f) failOnWarning = false
[DEBUG]   (f) forceJavacCompilerUse = false
[DEBUG]   (f) fork = false
[DEBUG]   (f) generatedSourcesDirectory = /home/karsten/svn/myit0004/target/generated-sources/annotations
[DEBUG]   (f) mojoExecution = org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile {execution: default-compile}
[DEBUG]   (f) optimize = false
[DEBUG]   (f) outputDirectory = /home/karsten/svn/myit0004/target/classes
[DEBUG]   (f) parameters = false
[DEBUG]   (f) project = MavenProject: mygroup:myit0004:1.0.0 @ /home/karsten/svn/myit0004/pom.xml
[DEBUG]   (f) projectArtifact = mygroup:myit0004:jar:1.0.0
[DEBUG]   (f) session = org.apache.maven.execution.MavenSession@3e84111a
[DEBUG]   (f) showDeprecation = false
[DEBUG]   (f) showWarnings = false
[DEBUG]   (f) skipMultiThreadWarning = false
[DEBUG]   (f) source = 12
[DEBUG]   (f) staleMillis = 0
[DEBUG]   (s) target = 12
[DEBUG]   (f) useIncrementalCompilation = true
[DEBUG]   (f) verbose = false
[DEBUG] -- end configuration --
[DEBUG] Using compiler 'javac'.
[DEBUG] Adding /home/karsten/svn/myit0004/target/generated-sources/annotations to compile source roots:
/home/karsten/svn/myit0004/src/main/java
[DEBUG] New compile source roots:
/home/karsten/svn/myit0004/src/main/java
/home/karsten/svn/myit0004/target/generated-sources/annotations
[DEBUG] CompilerReuseStrategy: reuseCreated
[DEBUG] useIncrementalCompilation enabled
[DEBUG] Stale source detected: /home/karsten/svn/myit0004/src/main/java/it0004/Hello.java
[INFO] Changes detected - recompiling the module!
[DEBUG] Classpath:
[DEBUG]  /home/karsten/svn/myit0004/target/classes
[DEBUG] Source roots:
[DEBUG]  /home/karsten/svn/myit0004/src/main/java
[DEBUG]  /home/karsten/svn/myit0004/target/generated-sources/annotations
[DEBUG] Command line options:
[DEBUG] -d /home/karsten/svn/myit0004/target/classes -classpath /home/karsten/svn/myit0004/target/classes: -sourcepath /home/karsten/svn/myit0004/src/main/java:/home/karsten/svn/myit0004/target/generated-sources/annotations: -s /home/karsten/svn/myit0004/target/generated-sources/annotations -g -nowarn -target 12 -source 12 -encoding UTF-8 -Xlint
[DEBUG] incrementalBuildHelper#beforeRebuildExecution
[INFO] Compiling 1 source file to /home/karsten/svn/myit0004/target/classes
[DEBUG] incrementalBuildHelper#afterRebuildExecution
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] /home/karsten/svn/myit0004/src/main/java/it0004/Hello.java:[3,14] package it0003 does not exist
[ERROR] /home/karsten/svn/myit0004/src/main/java/it0004/Hello.java:[8,9] cannot find symbol
symbol:   variable HelloWorldJNI
location: class it0004.Hello
[INFO] 2 errors
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  2.606 s
[INFO] Finished at: 2019-09-27T13:28:44Z
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project myit0004: Compilation failure: Compilation failure:
[ERROR] /home/karsten/svn/myit0004/src/main/java/it0004/Hello.java:[3,14] package it0003 does not exist
[ERROR] /home/karsten/svn/myit0004/src/main/java/it0004/Hello.java:[8,9] cannot find symbol
[ERROR]   symbol:   variable HelloWorldJNI
[ERROR]   location: class it0004.Hello

可以看出，依赖的 nar 文件不在 classPath 中，所以编译失败，因为它找不到依赖类。如何确保 nar 文件包含在类路径中？

Answer 1

找到了答案。我应该看看 it0025 的例子。需要添加到依赖项目pom.xml

的是

<plugin>
<groupId>com.github.maven-nar</groupId>
<artifactId>nar-maven-plugin</artifactId>
<version>${nar-plugin.version}</version>
<extensions>true</extensions>
<executions>
<execution>
<id>nar-download</id>
<goals>
<goal>nar-download</goal>
</goals>
</execution>
<execution>
<id>nar-test-unpack</id>
<goals>
<goal>nar-test-unpack</goal>
</goals>
</execution>
<execution>
<id>nar-integration-test</id>
<goals>
<goal>nar-integration-test</goal>
</goals>
</execution>
</executions>
</plugin>