多模块Maven项目中的Nar依赖关系 [英] Nar dependency in multi-module maven project
问题描述
我建立了一个多模块maven项目，该项目由一个旨在构建nar jni库的模块和一个依赖于该库的jar打包模块组成.
I set up a multi module maven project, which is comprised of a module destined to build nar jni library, and a jar packaged module that is dependent on that library.
我能够将nar库安装到本地maven存储库中，但是无法在相关模块中使用它.
I am able to install the nar library to my local maven repository, but I fail to use it in dependent module.
例如，我运行mvn nar:nar-unpack，我得到:
For instance, I run mvn nar:nar-unpack and I get:
[INFO] ------------------------------------------------------------------------
[INFO] Building nar-dependent 1.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- nar-maven-plugin:3.2.0:nar-unpack (default-cli) @ nar-dependent ---
[INFO] Unpacking 0 dependencies to /home/przemek/Documents/stimulant/nar-dependent/target/nar
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
似乎没有nar依赖性，这显然是不正确的. 此外，尝试执行使用jni库的类的main方法失败:
It seems that there are no nar dependencies, which is obviously not true. Moreover, trying to execute the main method of the class that makes use of the jni library fails:
mvn exec:java -Dexec.mainClass=App
[INFO] --- exec-maven-plugin:1.4.0:java (default-cli) @ nar-dependent ---
[WARNING]
java.lang.reflect.InvocationTargetException
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:497)
at org.codehaus.mojo.exec.ExecJavaMojo$1.run(ExecJavaMojo.java:293)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.UnsatisfiedLinkError: no nar-library-1.0-SNAPSHOT in java.library.path
at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1865)
at java.lang.Runtime.loadLibrary0(Runtime.java:870)
at java.lang.System.loadLibrary(System.java:1122)
at jnibook.NarSystem.loadLibrary(NarSystem.java:23)
at jnibook.HelloWorld.<clinit>(HelloWorld.java:10)
at App.main(App.java:9)
... 6 more
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
项目的结构如下:
.
├── nar-dependent
│ ├── pom.xml
│ └── src
│ └── main
│ └── java
│ └── App.java
├── nar-library
│ ├── pom.xml
│ └── src
│ ├── main
│ │ ├── c
│ │ │ └── HelloWorld.c
│ │ ├── include
│ │ ├── java
│ │ │ └── jnibook
│ │ │ └── HelloWorld.java
│ │ └── resources
│ └── test
│ └── java
├── parent
│ └── pom.xml
这是父pom.xml:
Here is the parent pom.xml:
<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>
<groupId>sidec</groupId>
<artifactId>stimulant</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<modules>
<module>../nar-library</module>
<module>../nar-dependent</module>
</modules>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.3</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.7</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>
nar-library模块pom.xml:
The nar-library module pom.xml:
<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>
<parent>
<groupId>sidec</groupId>
<artifactId>stimulant</artifactId>
<version>1.0-SNAPSHOT</version>
<relativePath>../parent/pom.xml</relativePath>
</parent>
<artifactId>nar-library</artifactId>
<packaging>nar</packaging>
<name>nar-library</name>
<properties>
<skipTests>true</skipTests>
</properties>
<build>
<plugins>
<plugin>
<groupId>com.github.maven-nar</groupId>
<artifactId>nar-maven-plugin</artifactId>
<version>3.2.0</version>
<extensions>true</extensions>
<configuration>
<cpp>
<exceptions>false</exceptions>
</cpp>
<libraries>
<library>
<type>jni</type>
<linkCPP>false</linkCPP>
<narSystemPackage>jnibook</narSystemPackage>
</library>
</libraries>
<javah>
<includes>
<include></include>
</includes>
</javah>
</configuration>
</plugin>
</plugins>
</build>
</project>
与nar相关的pom.xml
The nar-dependent pom.xml
<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>
<parent>
<groupId>sidec</groupId>
<artifactId>stimulant</artifactId>
<version>1.0-SNAPSHOT</version>
<relativePath>../parent/pom.xml</relativePath>
</parent>
<artifactId>nar-dependent</artifactId>
<packaging>jar</packaging>
<name>nar-dependent</name>
<build>
<plugins>
<plugin>
<groupId>com.github.maven-nar</groupId>
<artifactId>nar-maven-plugin</artifactId>
<version>3.2.0</version>
<extensions>true</extensions>
<!--<executions>-->
<!--<execution>-->
<!--<id>nar-download</id>-->
<!--<goals>-->
<!--<goal>nar-download</goal>-->
<!--</goals>-->
<!--</execution>-->
<!--</executions>-->
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>sidec</groupId>
<artifactId>nar-library</artifactId>
<version>1.0-SNAPSHOT</version>
<type>nar</type>
</dependency>
</dependencies>
</project>
最后，为了证明它确实是HelloWorld项目，它是一个库类:
Finally, as a proof that it is really the HelloWorld project, a library class:
package jnibook;
public class HelloWorld {
public native void print();
static {
NarSystem.loadLibrary();
}
}
和一个客户端应用程序:
and a client app:
import jnibook.HelloWorld;
public class App {
public static void main(String ... args){
(new HelloWorld()).print();
}
}
我引用了 https://maven-nar.github.io/examples.html没有成功. 我不知道出了什么问题.
I referenced https://maven-nar.github.io/examples.html with no success. I have no idea what is going wrong.
有什么想法吗? 此处为项目的zip .
推荐答案
这可能是一个过时的问题，但我会一一回答:
This might be an outdated question, but I'll answer all the same :
运行Java JNI应用程序时，必须告知在哪里可以找到保存有JNI使用的相关本机C代码的.so库. 例如，如果您在可执行jar jar.app中关闭了应用程序:
When running the java JNI app, it must be told where to find the .so library holding the relevant native C code used by JNI. For example, if you closed your app in the executable jar app.jar :
java -Djava.library.path=[path to the .so native C library] -jar app.jar
PS-您可以看到JVM由于以下异常而找不到本机C库:java.lang.UnsatisfiedLinkError: no nar-library-1.0-SNAPSHOT in java.library.path
PS - you can see that the JVM can't find the native C library thanks to the exception : java.lang.UnsatisfiedLinkError: no nar-library-1.0-SNAPSHOT in java.library.path
这篇关于多模块Maven项目中的Nar依赖关系的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
