Run an executable JAR with external class path

Question

Using Maven I compiled my project into a JAR that includes all the dependencies except for one big dependecy. The inclusion of the dependecies is done using:

<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.2.1</version>
<configuration>
    <archive>
      <manifest>
        <mainClass>com.mypackage.Main</mainClass>
      </manifest>
    </archive>
    <descriptorRefs>
        <descriptorRef>jar-with-dependencies</descriptorRef>
    </descriptorRefs>
</configuration>
<executions>
    <execution>
        <id>make-assembly</id> 
        <phase>package</phase>
        <goals>
            <goal>single</goal>
        </goals>
    </execution>
</executions>

Exclusion of dependencies is done with <scope>provided</scope>

The target myjar.jar is in the same folder as BigExternalJar.jar, but when I try to run:

java -cp ".:BigExternalJar.jar:myjar.jar" -jar myjar.jar

I get an exception for missing classes (those classes are from BigExternalJar.jar).

How can one pack dependencies into a JAR, using Maven only, but still be able to add additional JARs in classpath? Note that the BigExternalJar is not always in the same folder so I cannot add it manually to the MANIFEST file.

There are two similar questions that might look duplicate but they do not have an answer to this situation. Eclipse: How to build an executable jar with external jar? AND Running a executable JAR with external dependencies

Don't you use ; to separate class path entries (instead of :)? — J Fabian Meier, Nov 26 '17 at 18:40
`java -cp ... com.mypackage.Main`. -jar means: ignore -cp, use classpath specified in manifest. — JB Nizet, Nov 26 '17 at 18:41
@JBNizet Thanks. If so, I conclude from your comment that it is *not* possible to have some dependencies inside a jar then add additional classpath when executing. Correct? — Zoltán, Nov 26 '17 at 18:45
Not correct. As I said, just use `java -cp ... com.mypackage.Main`. — JB Nizet, Nov 26 '17 at 18:47

score 0 · Accepted Answer · answered Nov 27 '17 at 01:24

0

The classpath argument is ignored if you use the -jar option. Only the classpath provided in the manifest is used.

answered Nov 27 '17 at 01:24

user207421

305,947
44
307
483

score 0 · Answer 2 · answered Nov 27 '17 at 02:56

<build>
    <plugins>
        <!-- compiler插件, 设定JDK版本 -->
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <source>1.7</source>
                <target>1.7</target>
                <encoding>UTF-8</encoding>
            </configuration>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-shade-plugin</artifactId>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals>
                        <goal>shade</goal>
                    </goals>
                    <configuration>
                        <createDependencyReducedPom>false</createDependencyReducedPom>
                        <transformers>
                            <transformer
                                    implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
                                <mainClass>xxx.xxx.yourmain</mainClass>
                            </transformer>
                            <transformer
                                    implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                                <resource>META-INF/spring.handlers</resource>
                            </transformer>
                            <transformer
                                    implementation="org.apache.maven.plugins.shade.resource.AppendingTransformer">
                                <resource>META-INF/spring.schemas</resource>
                            </transformer>
                        </transformers>
                        <filters>
                            <filter>
                                <artifact>*:*</artifact>
                                <excludes>
                                    <exclude>META-INF/*.SF</exclude>
                                    <exclude>META-INF/*.DSA</exclude>
                                    <exclude>META-INF/*.RSA</exclude>
                                </excludes>
                            </filter>
                        </filters>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
</build>

pls try this~~~ all external jar will be in your packaged jar

Run an executable JAR with external class path

2 Answers2

Linked