我在一个maven项目中有一个用C编写的JNI共享库和相应的Java类，在另一个项目中有一个使用该类的应用程序。我使用nar-maven-plugin处理JNI。 版本： Maven的3.6.0 Java 12 nar插件3.6.0 我以nar-maven-plugin附带的集成测试3和4为例。 为此，我刚刚将POM更新为独立的并可以与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>
我在此项目上运行mvn install，并将其安装在我的.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
现在我使用它的压缩版本4对其进行测试，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();
}
}
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。依存关系用<type>nar</type>指定，这样就可以找到依存关系。但是nar文件不在classPath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
可以看到，依赖项的nar文件不在classPath中，所以编译失败，因为它找不到依赖项类。如何确定nar文件包含在classPath中？
答案 0 :(得分：0)
找到了答案。我应该看过it0025示例。需要添加到依赖项目的pom.xml中的是
<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>