If a user double-clicks on an executable JAR file, is it possible to check what version of Java that he or she has installed, and then display an appropriate message in a window that says that he or she needs to have X version of Java to run the application?
如果用户双击可执行JAR文件，是否可以检查他或她安装的Java版本，然后在窗口中显示相应的消息，表明他或她需要拥有X版本的Java运行应用程序？
I am creating an application that requires Java 7, and if a user does not have that version installed, I would like to display a message that says that he or she needs to download and install it.
我正在创建一个需要Java 7的应用程序，如果用户没有安装该版本，我想显示一条消息，说明他或她需要下载并安装它。
Of course, the user can type java -version, but it would be nice to display the version in a window for those who don't know how to check what version is installed. Is it possible to do so?
当然，用户可以键入java -version，但是对于那些不知道如何检查安装的版本的人来说，在窗口中显示版本会很不错。有可能这样做吗？
Or should I run some type of script to check before launching the application?
或者我应该在启动应用程序之前运行某种类型的脚本来检查？
2 个解决方案
#1
3
Check the System.getProperty("java.version")
检查System.getProperty（“java.version”）
You'll need to do some parsing, but this should give you a jumping of point
你需要做一些解析，但这应该给你一个跳跃点
#2
2
You can get the java version by using System.getProperty("java.version")
您可以使用System.getProperty（“java.version”）获取Java版本
See the documentation (http://docs.oracle.com/javase/tutorial/essential/environment/sysprop.html)
请参阅文档（http://docs.oracle.com/javase/tutorial/essential/environment/sysprop.html）
#1
3
Check the System.getProperty("java.version")
检查System.getProperty（“java.version”）
You'll need to do some parsing, but this should give you a jumping of point
你需要做一些解析，但这应该给你一个跳跃点
#2
2
You can get the java version by using System.getProperty("java.version")
您可以使用System.getProperty（“java.version”）获取Java版本
See the documentation (http://docs.oracle.com/javase/tutorial/essential/environment/sysprop.html)
请参阅文档（http://docs.oracle.com/javase/tutorial/essential/environment/sysprop.html）