java 运行错误

Posted 2023-02-14

不知道怎么回事，环境变量我也设置好了， 没有问题，可是每次编译的时候总会出现错误提示：

C:\Documents and Settings\user\桌面>javac HelloWorld.class
javac: invalid flag: HelloWorld.class
Usage: javac <options> <source files>
where possible options include:
-g Generate all debugging info
-g:none Generate no debugging info
-g:lines,vars,source Generate only some debugging info
-nowarn Generate no warnings
-verbose Output messages about what the compiler is doing
-deprecation Output source locations where deprecated APIs are u
sed
-classpath <path> Specify where to find user class files
-cp <path> Specify where to find user class files
-sourcepath <path> Specify where to find input source files
-bootclasspath <path> Override location of bootstrap class files
-extdirs <dirs> Override location of installed extensions
-endorseddirs <dirs> Override location of endorsed standards path
-d <directory> Specify where to place generated class files
-encoding <encoding> Specify character encoding used by source files
-source <release> Provide source compatibility with specified release

-target <release> Generate class files for specific VM version
-version Version information
-help Print a synopsis of standard options
-X Print a synopsis of nonstandard options
-J<flag> Pass <flag> directly to the runtime system

不知道是那里没有搞好，请高手指点！

javac命令是用来编译java源文件的，即以.java结尾的文件
java命令用来执行编译之后形成的class文件，你把两个命令搞混了 参考技术A 文件保存了吗？ 参考技术B javac HelloWorld.java

这样编译

运行：java HelloWorld 参考技术C java HelloWorld 就对了。