有没有办法强制maven(2.0.9)将所有依赖项包含在一个jar文件中?

我有一个项目的构建到一个单一的jar文件。我希望依赖的类也能复制到jar中。

更新:我知道我不能只在jar文件中包含一个jar文件。我正在寻找一种方法来解包指定为依赖项的jar,并将类文件打包到我的jar中。


当前回答

你可以使用带有"jar-with-dependencies"描述符的maven-assembly插件来做到这一点。下面是我们的pom.xml的相关代码块:

  <build>
    <plugins>
      <!-- any other plugins -->
      <plugin>
        <artifactId>maven-assembly-plugin</artifactId>
        <executions>
          <execution>
            <phase>package</phase>
            <goals>
              <goal>single</goal>
            </goals>
          </execution>
        </executions>
        <configuration>
          <descriptorRefs>
            <descriptorRef>jar-with-dependencies</descriptorRef>
          </descriptorRefs>
        </configuration>
      </plugin>
    </plugins>
  </build>

其他回答

我对月食Luna和m2eclipse的最终解决方案: 自定义类加载器(下载并添加到您的项目,只有5个类) : http://git.eclipse.org/c/jdt/eclipse.jdt.ui.git/plain/org.eclipse.jdt.ui/jar%20in%20jar%20loader/org/eclipse/jdt/internal/jarinjarloader/; 这个类加载器是单jar类加载器中最好的,而且非常快;

< project.mainClass > org.eclipse.jdt.internal.jarinjarloader.JarRsrcLoader < / project.mainClass > < project.realMainClass > my.Class < / project.realMainClass >

编辑JIJConstants“Rsrc-Class-Path”为“Class-Path” MVN清洁依赖:复制依赖包 是创建一个jar与依赖lib文件夹与一个瘦类加载器

<build>
    <resources>
        <resource>
            <directory>src/main/java</directory>
            <includes>
                <include>**/*.java</include>
                <include>**/*.properties</include>
            </includes>
        </resource>
        <resource>
            <directory>src/main/resources</directory>
            <filtering>true</filtering>
            <includes>
                <include>**/*</include>
            </includes>
            <targetPath>META-INF/</targetPath>
        </resource>
        <resource>
            <directory>${project.build.directory}/dependency/</directory>
            <includes>
                <include>*.jar</include>
            </includes>
            <targetPath>lib/</targetPath>
        </resource>
    </resources>
<pluginManagement>
        <plugins>

            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <configuration>
                    <archive>
                        <manifest>
                            <addClasspath>true</addClasspath>
                            <mainClass>${project.mainClass}</mainClass>
                            <classpathPrefix>lib/</classpathPrefix>
                        </manifest>

                        <manifestEntries>
                            <Rsrc-Main-Class>${project.realMainClass}  </Rsrc-Main-Class>
                            <Class-Path>./</Class-Path>
                        </manifestEntries>

                    </archive>
                </configuration>
            </plugin>
<plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-dependency-plugin</artifactId>
                <executions>
                    <execution>
                        <id>copy-dependencies</id>
                        <phase>package</phase>
                        <goals>
                            <goal>copy-dependencies</goal>
                        </goals>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </pluginManagement>
</build>

为了使它更简单,你可以使用下面的插件。

             <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal>
                        </goals>
                        <configuration>
                            <classifier>spring-boot</classifier>
                            <mainClass>
                                com.nirav.certificate.CertificateUtility
                            </mainClass>
                        </configuration>
                    </execution>
                </executions>
            </plugin>

http://fiji.sc/Uber-JAR提供了一个很好的解释:

There are three common methods for constructing an uber-JAR: Unshaded. Unpack all JAR files, then repack them into a single JAR. Pro: Works with Java's default class loader. Con: Files present in multiple JAR files with the same path (e.g., META-INF/services/javax.script.ScriptEngineFactory) will overwrite one another, resulting in faulty behavior. Tools: Maven Assembly Plugin, Classworlds Uberjar Shaded. Same as unshaded, but rename (i.e., "shade") all packages of all dependencies. Pro: Works with Java's default class loader. Avoids some (not all) dependency version clashes. Con: Files present in multiple JAR files with the same path (e.g., META-INF/services/javax.script.ScriptEngineFactory) will overwrite one another, resulting in faulty behavior. Tools: Maven Shade Plugin JAR of JARs. The final JAR file contains the other JAR files embedded within. Pro: Avoids dependency version clashes. All resource files are preserved. Con: Needs to bundle a special "bootstrap" classloader to enable Java to load classes from the wrapped JAR files. Debugging class loader issues becomes more complex. Tools: Eclipse JAR File Exporter, One-JAR.

如果你想做一个可执行的jar文件,他们也需要设置主类。所以全构型应该是。

    <plugins>
            <plugin>
                 <artifactId>maven-assembly-plugin</artifactId>
                 <executions>
                     <execution>
                          <phase>package</phase>
                          <goals>
                              <goal>single</goal>
                          </goals>
                      </execution>
                  </executions>
                  <configuration>
                       <!-- ... -->
                       <archive>
                           <manifest>
                                 <mainClass>fully.qualified.MainClass</mainClass>
                           </manifest>
                       </archive>
                       <descriptorRefs>
                           <descriptorRef>jar-with-dependencies</descriptorRef>
                      </descriptorRefs>
                 </configuration>
         </plugin>
   </plugins>

如果你(像我一样)不是特别喜欢上面描述的带依赖的罐子方法, 我更喜欢的maven解决方案是简单地建立一个war项目, 即使你只是在构建一个独立的Java应用程序:

Make a normal maven jar-project, that will build your jar-file (without the dependencies). Also, setup a maven war-project (with only an empty src/main/webapp/WEB-INF/web.xml file, which will avoid a warning/error in the maven-build), that only has your jar-project as a dependency, and make your jar-project a <module> under your war-project. (This war-project is only a simple trick to wrap all your jar-file dependencies into a zip-file.) Build the war-project to produce the war-file. In the deployment-step, simply rename your .war-file to *.zip and unzip it.

你现在应该有一个lib目录(你可以移动到你想要的地方),里面有你的jar和运行应用程序所需的所有依赖项:

java -cp 'path/lib/*' MainClass

(类路径中的通配符在Java-6或更高版本中有效)

我认为这样在maven中设置起来更简单(不需要使用汇编插件),而且可以更清楚地看到应用程序结构(您将在普通视图中看到所有依赖jar的版本号,并避免将所有内容都塞进一个jar文件中)。