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如何在OpenJDK中找到主类

[英]Java 9 gives “Main Class not found” ob Ubuntu, but file works on Windows and Mac // how to find main Class in OpenJDK

原文 2017-11-13 13:36:16 4 2 java/ ubuntu/ openjdk

So I have a jar file that works perfectly fine on Windows and Mac, but not on Ubuntu (the only place where Openjdk is installed) This question hints at OpenJDK being the problem: Java Application main class not found on Ubuntu So: how do I show OpenJDK the correct Main Class? 因此，我有一个jar文件，该文件在Windows和Mac上都可以正常运行，但在Ubuntu（无法安装Openjdk的唯一位置）上却无法正常工作。这个问题暗示了OpenJDK存在问题：在Ubuntu上找不到Java应用程序主类。显示正确的MainJDK OpenJDK？ (Its Client.class in /chat in the jar file) I know it has something to do with the MetaINF File, but I cant guess the correct input there. （其jar文件中/ chat中的Client.class）我知道它与MetaINF文件有关，但是我无法猜测那里的正确输入。 This is what's currently in the MANIFEST.MF file: 这是MANIFEST.MF文件中当前的内容：

Manifest-Version: 1.0 清单版本：1.0

Main-Class: Chat.Client 主类：Chat.Client

I cant find anything anywhere on the topic, but I also cant install the proprietary java on the Ubuntu PC, as its the one where the jar HAS to run and the one where I m not admin at. 我在该主题的任何地方都找不到任何东西，但是我也无法在Ubuntu PC上安装专有的Java，因为它是jar可以运行的地方，而我不是管理员。

2 个解决方案

Its Client.class in /chat in the jar file jar文件中/ chat中的Client.class

Then Main-Class: Chat.Client is incorrect, it should be Main-Class: chat.Client (lower case chat ). 然后Main-Class: Chat.Client不正确，应该是Main-Class: chat.Client （小写chat ）。

So probably not an OpenJDK issue, just the fact that some file systems are case-insensitive and others are case-sensitive. 因此，可能不是OpenJDK问题，而是某些文件系统不区分大小写而另一些文件区分大小写的事实。 You're almost certainly using a case-insensitive one on Windows. 您几乎可以肯定在Windows上使用了不区分大小写的代码。 I guess you must be on Mac as well, though I find that surprising. 我想您也必须在Mac上，尽管我觉得很奇怪。 You probably aren't on Ubuntu. 您可能不在Ubuntu上。

Not really an answer but an easy workaround for people with the same Problem: Install (installing is optional, you can use it directly after the download) the proprietary JDK from Oracle, and if you dont have admin privileges (I dont): you dont need them, simply download the Java JDK from oracle and start the .Jar with /pathtothedownloadedJDK/bin/java instead of "java" and then the usual -jar yourJarFile.jar 对于那些具有相同问题的人来说，这不是真正的答案，而是一个简单的解决方法：从Oracle安装专有的JDK（安装是可选的，您可以在下载后直接使用它），并且如果您没有管理权限（我没有）：您没有需要它们，只需从oracle下载Java JDK并使用/ pathtothedownloadedJDK / bin / java而不是“ java”启动.Jar，然后使用通常的-jar yourJarFile.jar

Tl:Dr: Get the JDK from Oracle, you dont need sudo to use it. Tl：Dr：从Oracle获得JDK，您不需要sudo即可使用它。