怎么查看本机安装的jdk版本与jre版本

Question

怎么查看本机安装的jdk版本与jre版本

Answer 1

System.out.println(System.getProperty("java.version"));
        System.out.println(System.getProperty("java.vendor"));
        System.out.println(System.getProperty("java.vendor.url"));
        System.out.println(System.getProperty("java.home"));
        System.out.println(System.getProperty("java.vm.specification.version"));
        System.out.println(System.getProperty("java.vm.specification.vendor"));
        System.out.println(System.getProperty("java.vm.specification.name"));
        System.out.println(System.getProperty("java.vm.version"));
        System.out.println(System.getProperty("java.vm.vendor"));
        System.out.println(System.getProperty("java.vm.name"));
        System.out.println(System.getProperty("java.specification.version"));
        System.out.println(System.getProperty("java.specification.vendor"));
        System.out.println(System.getProperty("java.specification.name"));
        System.out.println(System.getProperty("java.class.version"));
        System.out.println(System.getProperty("java.class.path"));
        System.out.println(System.getProperty("java.library.path"));
        System.out.println(System.getProperty("java.io.tmpdir"));
        System.out.println(System.getProperty("java.compiler"));
        System.out.println(System.getProperty("java.ext.dirs"));
        System.out.println(System.getProperty("os.name"));
        System.out.println(System.getProperty("os.arch"));
        System.out.println(System.getProperty("os.version"));
        System.out.println(System.getProperty("file.separator"));
        System.out.println(System.getProperty("path.separator"));
        System.out.println(System.getProperty("line.separator"));
        System.out.println(System.getProperty("user.name"));
        System.out.println(System.getProperty("user.home"));        
        System.out.println(System.getProperty("user.dir"));

Answer 2

System.out.println(System.getProperties());

Answer 3

在命令行窗口，输入： java -version

Answer 4

System.out.println(System.getProperties());

Answer 5

Properties prop = new Properties(System.getProperties());
//打印出jvm属性，这里有jvm所有的信息，
prop.list(System.out)