java - 依赖项不应指向项目目录中的文件

Question

我事先查看了这个问题，看到其他人也有类似的问题，但没有一个解决方案对我有用。

我是 Maven 的完全菜鸟，但我刚刚从 GitHub 导入了一个项目。现在我在让依赖项工作方面遇到了问题。当我清理它时，会出现以下错误。

SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
SLF4J: Defaulting to no-operation (NOP) logger implementation
SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further         details.
[INFO] Scanning for projects...
[WARNING] 
[WARNING] Some problems were encountered while building the effective model for com.walrusone.skywars:skywarsreloadedplugin-api:jar:API
[WARNING] 'dependencies.dependency.systemPath' for org.bukkit:bukkit:jar should not point at files within the project directory, ${project.basedir}/lib/bukkit-1.8.6-R0.1-SNAPSHOT.jar will be unresolvable by dependent projects @ line 19, column 19
[WARNING] 
[WARNING] Some problems were encountered while building the effective model for com.walrusone.skywars:skywarsreloadedplugin-v1_7_R3:jar:v1_7_R3
[WARNING] 'dependencies.dependency.systemPath' for org.bukkit:craftbukkit:jar should not point at files within the project directory, ${project.basedir}/lib/craftbukkit-1.7.9-R0.2-SNAPSHOT.jar will be unresolvable by dependent projects @ line 19, column 19
[WARNING] 
[WARNING] Some problems were encountered while building the effective model for com.walrusone.skywars:skywarsreloadedplugin-v1_7_R4:jar:v1_7_R4
[WARNING] 'dependencies.dependency.systemPath' for org.bukkit:craftbukkit:jar should not point at files within the project directory, ${project.basedir}/lib/craftbukkit-1.7.10-R0.1.jar will be unresolvable by dependent projects @ line 19, column 19
[WARNING] 
[WARNING] Some problems were encountered while building the effective model for com.walrusone.skywars:skywarsreloadedplugin-v1_8_R1:jar:v1_8_R1
[WARNING] 'dependencies.dependency.systemPath' for org.bukkit:craftbukkit:jar should not point at files within the project directory, ${project.basedir}/lib/craftbukkit-1.8.jar will be unresolvable by dependent projects @ line 19, column 19
[WARNING] 
[WARNING] Some problems were encountered while building the effective model for com.walrusone.skywars:skywarsreloadedplugin-v1_8_R2:jar:v1_8_R2
[WARNING] 'dependencies.dependency.systemPath' for org.bukkit:craftbukkit:jar should not point at files within the project directory, ${project.basedir}/lib/craftbukkit-1.8.3.jar will be unresolvable by dependent projects @ line 19, column 19
[WARNING] 
[WARNING] Some problems were encountered while building the effective model for com.walrusone.skywars:skywarsreloadedplugin-v1_8_R3:jar:v1_8_R3
[WARNING] 'dependencies.dependency.systemPath' for org.bukkit:craftbukkit:jar should not point at files within the project directory, ${project.basedir}/lib/craftbukkit-1.8.4.jar will be unresolvable by dependent projects @ line 19, column 19
[WARNING] 
[WARNING] Some problems were encountered while building the effective model for com.walrusone.skywars:SkyWarsReloadedPlugin:jar:V2.8
[WARNING] 'dependencies.dependency.systemPath' for org.bukkit:bukkit:jar should not point at files within the project directory, ${project.basedir}/lib/craftbukkit-1.8.4.jar will be unresolvable by dependent projects @ line 72, column 25
[WARNING] 
[WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING] 
[WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING] 

我相信这与告诉我它找不到它的原始错误不同，所以我继续下载所有 .jar 文件并将其放在正确的位置。现在我不知道该怎么办。

我遇到的另一个问题是，每当我尝试编辑或添加一个类时，它都不像普通的 jar 文件。当我键入 Main 时，我不能像 Main.instance.staticMethod() 那样做。它只是坐在那里。

如果您需要任何其他文件，请告诉我。

另外，如果有人知道关于 maven 的任何好的教程视频

Answer 1

maven 的要点是您应该 不必下载依赖项。只需克隆该项目。您应该在根目录中看到一个文件 pom.xml。然后输入

mvn compile

这应该会编译软件并下载正在进行的依赖项。依赖项不存储在项目文件夹中，它们使用默认配置放在 ~/.m2/... 中。

编辑:警告似乎是项目维护者没有正确理解 maven 引起的问题。他们似乎在项目中添加了 jars 而不是依赖项。

下一步编辑:例如考虑 v1_8_R3 模块中的文件 pom.xml:它链接到基本目录中的 jars:

<dependency>
  <groupId>org.bukkit</groupId>
  <artifactId>craftbukkit</artifactId>
  <version>1.8.4-R0.1-SNAPSHOT</version>
  <scope>system</scope>
  <systemPath>${project.basedir}/lib/craftbukkit-1.8.4.jar</systemPath>
  <type>jar</type>
  <optional>true</optional>
</dependency>

通常不鼓励使用系统路径。 正确的 方法是开发人员将 jar 作为单独的 Artifact 发送。参见 this question and the related answers